1.GENERAL 1.1 GUARANTEED TECHNICAL PARTICULARS The Contract Works shall comply with the guaranteed technical particulars as per REC/CEA guide lines.
1.2 ERECTION AT SITE AND ACCOMMODATION The Contractor shall provide, at his own cost and expense, all labors, plant and material necessary for
unloading and erection at the Site and shall be entirely responsible for its efficient and correct operation.
The Contractor shall be responsible for arranging and providing all living accommodation services and
amenities required by his employees. 1.3 Use of electrical energy The Contractor shall arrange at his own cost and expense, any site supplies of electrical energy which he
may require for supplying power for heavy erection plant, welding plant or other tools, lighting and testing
purposes.All wiring for such tackle and for lighting from the point of supply shall be provided by the
Contractor and all such installations shall comply with all appropriate statutory regulations.
1.4 RESPONSIBILITY OF THE CONTRACTOR Until each Section of the Contract Works has been taken over or deemed to have been taken over under
the Conditions of Contract, the Contractor shall be entirely responsible for the Contract Works, whether
under construction, during tests, or in use for the Employer‟s service. 1.5 COMPLIANCE WITH REGULATIONS All apparatus and material supplied, and all works carried out shall comply in all respects with such of the
requirements of all Regulations and Acts in force in the country and state in particular of the Employer as
are applicable to the Contract Works and with any other applicable regulations to which the Employer is
subjected to oblige. 1.6 MAINTENANCE AND CLEARING OF SITE The placing of materials and plant near the erection site prior to their being erected and installed shall be
done in a neat, tidy and safe manner. The Contractor shall at his own expense keep the site area allocated
to him and also the erection area of the Contract Works reasonably clean and shall remove all waste
material as it accumulates and as directed by the Engg In-charge from time to time. 1.7 INSURANCE 1.7.1 Worksmen's Compensation Insurance This insurance shall protect the Contractor against all claims applicable under the worksmen‟s Compensation Act, 1948 (Government of India). This policy shall also cover the Contractor against the
claims for injury, disability, disease or death of his or his sub-contractor's employees, which for any reason
are not covered under the Worksmen‟s Compensation Act, 1948. The liabilities shall not be less than; a. Worksmen‟s Compensation- As per statutory provisions a Employee's liability-As per statutory provisions According to the Govt. rules. b Comprehensive automobile insurance This insurance shall be in a such a form to protect the Contractor against all claims for injuries, disability,
disease and death to members of public including the Employer's men and damage to the property of
others arising from the use of motor vehicles during on or off the Site operations, irrespective of the
ownership of such vehicles and as per latest prevailing Govt. rules. d. Comprehensive General Liability Insurance
This insurance shall protect the Contractor against all claims arising from injuries, disabilities, disease or
death of members or public or damage to property of others, due to any act or omission on the part of the
Contractor, its agents, its employees, its representatives and sub-contractors or from riots, strikes and civil
commotion. The hazards to be covered will pertain to all works and areas where the Contractor, its sub-
contractors, agents and employees have to perform works pursuant to the Contracts. 1.7.2 WORKS AND SAFETY REGULATIONS The Contractor shall ensure safety of all the workmen, plant and equipment belonging to him or to others,
working at the Site. The Contractor shall also provide for all safety notices and safety equipment required
by the relevant legislation and deemed necessary by the Engg- In-charge.
1.7.2.1 Drawings Within 07 days of contract commencement the Contractor shall submit, for approval by the SOUTHCO
Utility, a schedule of the drawings to be produced detailing which are to be submitted for "Approval" and
which are to be submitted "For Information Only". The schedule shall also provide a programme of drawing
submission, for approval by the Engineer in charge that ensures that all drawings and calculations are
submitted within the period specified above.
1.1.2 GENERAL PARTICULARS OF SYSTEM
System description
The following are the general particulars governing the design and working of the complete system of
which the Contract Works will eventually form a part: The system is three phase, 50 Hz and power is to
be distributed to consumers under SOUTHCO at appropriate voltage level.
Sl.No. DescriptionofTechnicalParameters Unit
11KV
1 Nominal system voltage KVrms 11 KV
2 Maximumsystem voltage KVrms 12.KV
3 Powerfrequency withstand voltage KVrms 28KV
Lightningimpulsewithstand voltage KVp 75KVp
4 a)Lineto earth 85KVp
b) Acrossisolatinggap
One minutepowerfrequencywithstand value
5 Dry KVrms 35
Wet KVrms
35
6 Systemfrequency Hz 50
7 Variation in frequency % 2.5
8 Continuouscurrentrating Amp 1250
9 Symmetrical short circuit current kA 25
10 Duration of short circuit fault current Sec 3
11 Dynamicshort circuit currentrating kAp
12 Design ambient temperatures ˚C 50
13 Pollution levelas per IEC-815 and 71 III
14 Maximumfault clearingtime Ms
notexceeding
150ms
Safetyclearances
1. Sectionclearance Meters 3 4 2. Groundclearances( betweengroundand
bottom most part of energized object)
i.Alonga streetii. Meters 5.791 5.791
Acrossa street
15 6.096 6.06
3. Horizontalclearancebetween the fence/
building, structure and energized object Meters 3.64
1.2 DATA
1.2.1 METEROLOGICAL
Description Data
Annual mean of maximum monthly average temperature. 50
Annual mean of minimum monthly temperature in ˚C 5
Average rain fall in mm 1500
Average thunder storms days per year 77days
Design ambient temperature in ˚C 50
Maximum wind velocity in meter/sec. 50
Maximum relative humidity in % 100
Average relative humidity in % 85 1.3 GUARANTEES TECHNICAL PARTICULARS
The Contract Works shall comply with the guaranteed technical particulars as per REC/CEA guide lines.
All materials supplied under this Contract shall be to the approval of the Engineer In-charge . 1.4 ERECTION AT SITE AND ACCOMMODATION Use of electrical energy The Contractor shall arrange at his own cost and expense, any site supplies of electrical energy which he
may require for supplying power for heavy erection of materials or other tools, lighting and testing purposes.
All such installations shall comply with all appropriate statutory regulations. 1.5 RESPONSIBILITY FOR THE WORK COMPLETION BY CONTRACTOR Until each Section of the Contract Works has been taken over or deemed to have been taken over under
the Conditions of Contract, the Contractor shall be entirely responsible for the Contract Works, under
construction, or in use for the owner‟s service. 1.6 COMPLIANCE WITH REGULATIONS All apparatus and material supplied, and all works carried out shall comply in all respects with such of the
requirements of all Regulations and Acts in force in the country and state in particular of the owner as are
applicable to the Contract Works and with any other applicable regulations to which the owner is subjected
to oblige. 1.7 MAINTENANCE AND CLEARING OF SITE The placing of materials near the erection site prior to their being erected and installed shall be done in a
neat, tidy and safe manner. The Contractor shall at his own expense keep the site area and erection area
of the Contract Works reasonably clean and shall remove all waste material as it accumulates and as
directed by the Engineer In-charge from time to time.
1.8
The Contractor shall ensure safety of all the workmen, material, equipment belonging to him or to others,
working at the Site. The Contractor shall also provide for all safety notices and safety equipment required
by the relevant legislation and deemed necessary by the Engineers-In charge.
TECHNICAL SPECIFICATION For Construction of 11KV Line,LT line and DP Mounted S/S 1.0 Survey & scope of works:
1.1 Survey shall be carried out by the contractor for the new line. 1.2 Aligning / erection of poles in the route of line along with strengthening of its foundation is in the scope of bidder. 1.3 Before undertaking the construction works in the given line the bidder shall make Assessment of the required materials in consultation /presence of representative of the bidder and accordingly the BOQ of the works is to be get it approved from the Engineer-in charge. 1.4 Any other works not mentioned above exclusively but required for accomplishing desired works will be in the scope of the bidder.
1.5 For all above activities shutdown shall be arranged by the subject to advanced notice in writing by the bidder.
1.6 While placing the equipment, if any equipment gets damaged due to negligent handling of the
contractor, the same shall be back charged to the contractor at panel rate.
2.0 Crossings 2.0.1 Road Crossings:- At all road crossings, the poles shall be fitted with strain type insulators. The
ground clearance from the road surfaces under maximum sag condition shall be as per IS 5613. 2.0.2 Power Line Crossings- Where the line is to cross over another line of the same voltage or lower
voltage, provisions to prevent the possibility of their coming into contact with each shall be made in
accordance with the Indian Electricity Rules, 1956 as amended from time to time. All the works related
to the above proposal shall be deemed to be included in the scope of the contractor. 3.0 Details Enroute-After survey and finalization of route, the contractor shall submit detailedroute map for each line.
This would be including following details:
c) Clearance from Ground, Building, Trees etc. – Clearance from ground, buildings, trees and telephone
lines shall be provided in conformity with the CEA guideline as amended up to date. The bidder shall
select the height of the poles in order to achieve the prescribed electrical clearances. 4.0 Final Schedule-The final schedule including Bill of quantity indicating location of poles
specificallymarking locations of failure containment pole/structure, DTs 11 kV line sectionalizes, line tapping
points angle of deviation at various tension pole locations, all type of crossings and other details shall be
submitted for the approval of the Owner.
3.1 Excavation of Pits
a) For excavation of the foundation pit, a hole should be drilled in the ground preferably with the use of
earth-augers. However, if earth-augers are not available, a pit shall be made in the direction of the line
for all the locations, except the locations of failure containment structures. The minimum planting depth
of poles shall be governed by IS: 1678. However due to the ground conditions e.g. water logged area
etc. depth of planting of poles shall be suitably increased with prior approval of the Engineer In charge. b) Excavation cost for pits shall be included by the contractor in the bid for pole erection for
following type of soils inclusive of dewatering of pits and shorting and shuttering wherever necessary. i) All type of soils and soil conditions including hard rock. ii) Hard rock No separate claim for dewatering during excavation, shoring and shuttering shall be
entertained. For hard rock, the excavation cost per location shall remain same for
all type of foundations. c) In case of non-availability of earth-augers, the pits shall be excavated with pick axes, crow bar and
shovels. Controlled blasting shall be permitted only in case of hard or rocky soil. The contractor shall be
responsible for any damage or accidents arising out of the process of blasting. Blasting is not permitted
if the area around location is inhabited. In such case,
the contractor shall have to follow other methods like drilling etc.
4.0 INSPECTION
All tests and inspection shall be made in the manufacturer‟s works unless otherwise specifically agreed
upon by the manufacturer and purchaser at the time of placement of purchase order. The manufacturer
shall afford to the inspector representing the purchaser, all reasonable facilities, without charge to satisfy
him that the material being furnished is in accordance with these specifications. The purchaser reserves the
right to get an component/material being used by the manufacturer tested from any recognized test house. The inspection by the purchaser or his authorized representative shall not relieve the contractor of his
obligation of furnishing equipment in accordance with the specifications.
TECHNICAL SPECIFICATIONS THE SPECIFICATION OF ALL MAJOR MATERIAL SHALL BE AS PER REC STANDARDS
All materials, which are to be supplied by the contractor,
should be procured from the approved Vendors of Southco
utility. Procurement from any other suppliers will not be-----
PSC Pole (8 Mtr. x 200 Kg & 9 Mtr. x 300 Kg) TECHNICAL SPECIFICATIONS
1. Applicable Standard :
The Poles shall comply with latest standards as following:
a) REC Specification No. 15/1979, REC Specification No. 24/1983 b) IS 1678, IS 2905, IS 7321
2. Materials :
Cement
The cement used in the manufacture of pre-stressed concrete poles shall be ordinary for rapid hardening Portland cement confirming to IS: 269-1976 (Specification for ordinary and low heat Portland cement) or IS: 8041 E-1978 (Specification for rapid hardening Portland cement).
Aggregates
Aggregates used for the manufacture of pre-stressed concrete poles shall confirm to IS: 383 (Specification for coarse and fine aggregates from natural sources for concrete) .The nominal maximum sizes of aggregates shall in no case exceed 12 mm.
Water
Water should be free from chlorides, sulphates, other salts and organic matter. Potable water will be generally suitable.
Admixture
Admixture should not contain Calcium Chloride or other chlorides and salts which are likely to promote corrosion of pre-stressing steel. The admixture shall conform to IS: 9103.
Pres-Stressing Steel
The pre-stressing steel wires including those used as un tensioned wires should conform to IS:1785 (Part-I) (Specification for plain hard-drawn steel wire for pre-stressed concrete, Part-I cold drawn stress relieved wire).IS:1785 (Part-II)(Specification for plain hard-drawn steel wire) or IS:6003 (Specification for indented wire for pre-stressed concrete).The type design given in the annexure are for plain wires of 4 mm diameter with a guaranteed ultimate strength of 160 kg/mm².
All pre-stressing steel shall be free from splits, harmful scratches, surface flaw, rough, aged and imperfect edges and other defects likely to impair its use in pre-stressed concrete.
Concrete Mix
The concrete mix shall be designed to the requirements laid down for controlled concrete (also called design mix concrete) in IS: 1343-1980 (Code of practice for pre-stressed concrete) and IS: 456 – 1978 (Code of practice for plain and reinforced concrete) subject to the following special conditions:
a) Minimum works cube strength at 28 days should be at least 420 Kg/cm². b) The concrete strength at transfer should be at least 210 Kg/cm². c) The mix should contain at least 380 Kg of cement per cubic meter of concrete. d) The mix should contain as low water content as is consistent with adequate workability.
It becomes necessary to add water to increase the workability the cement content also should be raised in such a way that the original value of water cement ratio is maintained.
3. Design Requirements
The poles shall be designed for the following requirements:
The poles shall be planted directly in the ground with a planting depth as per IS: 1678. Wherever, planting depth is required to be increased beyond the specified limits or alternative arrangements are required to be made on account of ground conditions e.g. water logging etc., the same shall be in the scope of the bidder at no extra cost to owner. The bidder shall furnish necessary design calculations/details of alternative arrangements in this regard.
The working load on the poles should correspond to those that are likely to come on the pole during their service life.
The factor of safety for all poles 9.0Mts.Shall not be less than 2.0 and for 8.0 M poles, the factor of safety shall not be less than 2.5.
The average permanent load shall be 40% of the working load. The F.O.S. against first load shall be 1.0. At average permanent load, permissible tensile stress in concrete shall be 30 kg/cm². At the design value of first crack load, the modulus of rupture shall not exceed
53.0kg/cm² for M-40. The ultimate moment capacity in the longitudinal direction should be at least one
fourth of that in the transverse direction. The maximum compressive stress in concrete at the time of transfer of pre-stress
should not exceed 0.8 times the cube strength. The concrete strength at transfer shall not be less than half, the 28 days strength
ensured in the design, i.e. 420x0.5=210kg/cm².
For model check calculations on the design of poles, referred to in the annexure, a reference may be made to the REC “Manual on Manufacturing of solid PCC poles, Part-I- Design Aspects”.
4 Dimensions and Reinforcements
The cross-sectional dimensions and the details of pre-stressing wires should conform to the particulars given in the enclosed drawing NH/RE/PSC/01.
The provisions of holes for fixing cross-arms and other fixtures should conform to the REC specification No. 15/1979.
5 Manufacture
All pre-stressing wires and reinforcements shall be accurately fixed as shown in drawings and maintained in position during manufacture. The un-tensioned reinforcement as indicated in the drawings should be held in position by the use of stirrups which should go round all the wires.
All wires shall be accurately stretched with uniform pre-stressed in each wire. Each wire or group of wires shall be anchored positively during casing. Care should be taken to see that the anchorages do not yield before the concrete attains the necessary strength.
6 Cover
The cover of concrete measured from the outside of pre-stressing tendon shall be normally 20 mm.
7 Welding and Lapping of Steel The high tensile steel wire shall be continuous over the entire length of the tendon. Welding shall not be allowed in any case. However, joining or coupling may be permitted provided the strength of the joint or coupling is not less than the strength of each individual wire.
8 Compacting Concrete shall be compacted by spinning, vibrating, shocking or other suitable mechanical means. Hand compacting shall not be permitted.
9 Curing
The concrete shall be covered with a layer of sacking, canvass, Hessian or similar absorbent material and kept constantly wet up to the time when the strength of concrete is at least equal to the minimum strength of concrete at transfer of pre-stress. Thereafter, the pole may be removed from the mould and watered at intervals to prevent surface cracking of the unit the interval should depend on the atmospheric humidity and temperature.
The pre-stressing wires shall be de-tensioned only after the concrete has attained the specified strength at transfer (i.e. 200 or 210 kg/cm² as applicable).The cubes cast for the purpose of determining the strength at transfer should be coursed, a sear as possible, under condition similar to those under which the poles are cured. The transfer stage shall be determined based on the daily tests carried out on concrete cubes till the specified strength indicated above is reached. Thereafter the test on concrete shall be carried out as detailed in IS: 1343(code of practice for pre-stressed concrete). The manufacture shall supply, when required by the owner or his representative, result of compressive test conducted in accordance with IS: 456 (Code of practice for plain and reinforced concrete) on concrete cubes made from the concrete used for the poles. If the manufacture so desired, the manufacture shall supply cubes for test purpose and such cubes shall be tested in accordance with IS: 456 (Code of practice for plain and reinforced concrete).
10 Lifting Eye-Hooks or Holes
Separate eye-hooks or hoes shall be provided for handling the transport, one each at a distance of 0.15 times the overall length, from either end of the pole. Eye-hooks, if provided, should be properly anchored and should be on the face that has the shorter dimension of the cross-section. Holes, if provided for lifting purpose, should be perpendicular to the broad face of the pole.
11 Holes for Cross Arms etc
Sufficient number of holes shall be provided in the poles for attachment of cross arms and other equipments.
12 Stacking & Transportation
Stacking should be done in such a manner that the broad side of the pole is vertical. Each tier in the stack should be supported on timber sleeper located as 0.15 times the overall length, measured from the end. The timber supported in the stack should be aligned in vertical line.
13 Earthing
Earthing shall be provided by having length of 8 SWG GI wire embedded in Concrete during manufacture and the ends of the wires left projecting from the pole to a length of 100mm at 250 mm from top and 150 mm below ground level.
Earth wire shall not be allowed to come in contract with the pre-stressing wires.
TECHNICAL SPECIFICATION
HT & LT STAY SETS
1.0 SCOPE
This specification covers design, manufacture, testing and dispatch of GI Stay Sets of 16
mm and 20 mm dia.
2.0 GENERAL REQUIREMENTS
2.1 16 MM Dia Stay sets (Galvanized) – LT Stay Set
This stay sets (Line Guy set) will consist of the following components:-
2.1.1. Anchor Rod with one washer and Nut
Overall length of rod should be 1800 mm to be made out of 16 mm dia GS Rod, one end
threaded up to 40 mm length with a pitch of 5 threads per cm and provided with one
square GS washer of size 40X40x1.6mm and one GS hexagonal nut conforming to
IS:1367:1967 & IS:1363:1967. Both waster and nut to suit threded rod of 16 mm dia. The
other end of the rod to be made into a round eye having an inner dia of 40mm with best
quality welding.
2.1.2. Anchor Plate Size 200 x 200 x6 mm
To be made out of GS plate of 6 mm thickness. The anchor plate should have at its centre
18 mm dia hole.
2.1.3 Turn Buckle & Eye Bolt with 2 Nuts
To be made of 16 mm dia GS Rod having an overall length of 450mm, one end of the rod to
be threaded up to 300 mm length with a pitch of 5 threads per cm and provided with two GS
Hexagonal nuts of suitable size conforming toIS:1363:1967 & IS:1367:1967. The other end of rod shall be rounded into a circular eye of 40mm inner
dia with proper and good quality welding.
2.1.4. Bow with Welded Angle
To be made out of 16mm dia GS rod. The finished bow shall have an over all length of
995 mm and eight of 450 mm, the apex or top of the bow shall be bent at an angle of 10
R. The other end shall be welded with proper and good quality welding to a GS angle
180 mm long having a dimension of 50x50x6mm. The angle shall have 3 holes of 18 mm
dia each.
2.1.5 Thimble
To be made on 1.5 mm thick GS sheet into a size of 75x22x40mm and shape as per
standard shall be supplied.
Average Weight of Finished 16mm Stay Sets shall be at least 7.702 KG (Minimum)
(Excluding Nuts Thimbles and Washer) 8.445 Kg. (Maximum)
2.2 20 mm Dia Stays Sets for 11 KV,33 KV Lines (Galvanized) HT Stay Set
The Stay Set (Line Guy Set) will consist of the following components:
2.2.1 Anchor Rod with one Washer and Nut
Overall length of Rod should be 1800mm to be made out of 20 mm dia GS Rod, one end
threaded up to 40 mm length with a pitch of threads per cm. And provided with one
square G.S. Washer of Size 50x50x1.6mm and one GS Hexagonal nut conforming to IS:
1363:1967 & IS:1367:1967. Both washer and nut to suit the threaded rod of 20mm. The
other end of the rod to be made into a round eye having an inner dia of 40mm with best
quality welding. Dimensional and other details are indicated and submitted by bidders for
owner‟s approval before start of manufacturing.
2.2.2 Anchor Plate Size 300 x 300 x 8 mm
To be made out of G.S. Plate of 8 mm thickness. The anchor plate 3+ to
have at its centre 22mm dia hole.
2.2.3 Turn Buckle, Eye Bolt with 2 Nuts.
To be made of 20 mm dia G.S. Rod having an overall length of 450 mm. One end of the
rod to be threaded up to 300 mm length with a pitch of 4 threads per cm. The 20 mm dia
bolt so made shall be provided with two G.S. Hexagonal nuts of suitable size conforming
to IS: 1363:1967 & IS: 1367:1967.
The other end of the rod shall be rounded into a circular eye of 40mm inner dia with
proper and good quality of welding. Welding details are to be indicated by the bidder
separately for approval.
2.2.4 Bow with Welded Channel:
To be made out of 16mm dia G.S.Rod. The finished bow shall have and overall length of
995 mm ad height of 450 mm. The apex or top of the bow shall be bent at an angle of
10R. he other end shall be welded with proper and good quality welding to a G.S.
Channel 200 mm long having a dimension of 100x50x4.7 mm.
The Channel shall have 2 holes of 18 mm dia and 22 dia hole at its centre as per drawing
No.3 enclosed herewith.
2.2.5 Thimble 2 Nos.
To be made of 1.5 mm thick G.S sheet into a size of 75x22x40mm and shape as per
standard.
2.2.6 Galvanizing
The complete assembly shall be hot dip galvanized as per ISS.
2.2.7. Welding
The minimum strength of welding provided on various components of 16mm and 20 mm
dia stay sets shall be 3100 kg & 4900 kg respectively. Minimum 6mm filet weld or its
equivalent weld area should be deposited in all positions of the job i.e. at any point of the
weld length. The welding shall be conforming to relevant IS:823/1964 or its latest
amendment.
2.2.8. Threading
The threads on the Anchor Rods, Eye Bolts and Nuts shall be as per specification IS;
4218:1967 (ISO Metric Screw Threads). The Nuts shall be conforming to the
requirements of IS: 1367:1967 and have dimension as per IS 1363:1967. The mechanical
property requirement of fasteners shall confirm to the properly clause 4.6 each for anchor
rods and Eye bolt and property clause 4 for nuts as per IS: 1367:1967.
Average weight of finished 20 mm Stays Set: 14.523 Kg.(Min) (Excluding Nuts Thimble
& Washer) :15.569 Kg. (Max.)
3.0 TESTS
The contractor shall be required to conduct testing of materials at Govt./Recognized
testing laboratory during pre-dispatch inspection for Tensile Load of 3100 Kg/4900Kg.
applied for one minute on the welding and maintained for one minute for 16 mm and
20mm dia stay sets respectively.
4.0 IDENTIFICATION MARK
All stay sets should carry the identification mark of the Purchaser
(NESCO/WESCO/SOUTHCO) as applicable. This should be engraved on the body of
stay rods to ensure proper identification of the materials.
The nuts should be of a size compatible with threaded portion of rods and there should be
not play or slippage of nuts.
Welding wherever required should be perfect and should not give way after erection.
5.0 TOLERANCES
The tolerances for various components of the stay sets are indicated below subject to the
condition that the average weight of finished stay sets of 16mm dia excluding nuts,
thimbles and washers shall not be less than the weight specified above:-
HT / LT STAY SETS
GURANTEED TECHNICAL PARTICULARS
Item Specified
Sl Descript Paramete
No. ion rs Section Type of stay Bidder’s offer Tolerance Fabrication sets
s Tolerances
Mate
rial
1. Anchor 6mm thick 200x200mm GS Plate 6 LT Stay Set
Plate +2.5%-5% +1%
mm
thick
8mm
GS
Plate 8 HT Stay Set
thick+2.5 300x300mm
mm
thick
%-5% +1%
2. Anchor 16mmdia Length GS Round LT Stay Set
Rod +5%- 3% 1800mm+0.
16mm
dia
5%
GS
Round
Rounded
16mm
dia
Eye 40 mm
HT Stay Set
20mm dia inside dia +
GS
Round
+3%-2% 3%
20mm
dai
Threading
GS
Round
40mm
20mm
dia
+11%-5%
Length
1800mm
+0.5%
Round Eye
40mm
inside dia +
3%.
Threading
40mm
+11%-5%
3. Turn 16mm dia Length GS Round LT Stay Set
Buckle +5%-3% 995mm
16mm
dia.
Bow +1% 16mm
HT Stay Set
dia
GS
Angle
Length180
mm +1% G S
50x50x6mm
Chann
el
100x50
x4.7
Channel mm
length
200mm +
1%
4. Eye Bolt 16mm dia Length GS Round LT Stay Set
Rod +5%-3% 450mm +
16 mm
dia
1%
Threading
300mm
HT Stay Set
20mm dia +1% Round
GS
Round
+ 3% -2% Eye 40mm
20mm
dia.
inside
dia+3%
Length450
mm +1%
Threading
300mm
+1% Round
Eye 40 mm
inside dia
+3%
5 Galvanis LT Stay Set
ation
thickness HT Stay Set
a Anchor LT Stay Set
Plate
HT Stay Set
b Anchor LT Stay Set
Rod
HT Stay Set
c Turn LT Stay Set
Buckle
Bow HT Stay Set
d Eye Bolt LT Stay Set
Rod
HT Stay Set
6 Weight LT Stay Set
of
complete
HT Stay Set
set
7 Whether
drawing
submitte
d
TECHNICAL SPECIFICATIONS
STAY WIRE (7/8, 7/10 & 7/12 SWG)
1.0 Application Standards
Except when they conflict with the specific requirements of this specification, the
G.I Stay Stranded Wires shall comply with the specific requirements of IS: 2141-
1979. IS: 4826-1979 & IS: 6594-1974 or the latest versions thereof.
2.0 Application and Sizes
a) The G.I. stranded wires covered in this Specification are intended for use on
the overhead power line poles, distribution transformer structures etc.
b) The G.I stranded wires shall be of 7/8 SWG (7/mm for 33 KV lines, 7/10SWG
(7/3.15 mm for 11KV lines and 7/12 SWG 7/2.5 mm for LT lines standard
sizes.
3.0 Materials
The wires shall be drawn from steel made by the open hearth basic oxygen or
electric furnace process and of such quality that when drawn to the size of wire
specified and coated with zinc, the finished strand and the individual wires shall
be of uniform quality and have the properties and characteristics as specified in
this specification. The wires shall not contain sulphur and phosphorus exceeding
0.060% each.
3.1 Tensile Grade
The wires shall be of tensile grade 4, having minimum tensile strength of 700
N/mm² conforming to 1S:2141.
3.2 General Requirements
a) The outer wire of strands shall have a right-hand lay.
b) The lay length of wire strands shall be 12 to 19 times the strand diameter.
3.3 Minimum Breaking Load & Galvanising
The minimum breaking load of the wires before and after stranding shall be as
follows:
Min. breaking
load of the
Single wire Min. breaking load
No. of Wires Wire Dia before of the standard
& Const. (mm) stranding (KN) wire (KN)
7 (6/1) 2.5 3.44 21.40
7 (6/1) 3.15 5.46 34.00
7 (6/1) 4.0 8.80 54.9 Minimum
weight of
490 gm/mm2 490 gm/mm2 490 gm/mm2 zinc coating
before
stranding
Minimum
weight of
475 gm/mm2 475 gm/mm2 475 gm/mm2 zinc coating
before
stranding
4.0 Construction
a) The galvanized stay wire shall be of 7-wire construction. The wires shall be so
stranded together that when an evenly distributed pull is applied at the ends of
completed strand, each wire shall take an equal share of the pull.
b) Joints are permitted in the individual wires during stranding but such joints
shall not be less than 15 metres apart in the finished strands.
c) The wire shall be circular and free from scale, irregularities, imperfection,
flaws, splits and other defects.
5.0 Tolerances
A tolerance of (+) 2.5% on the diameter of wires before stranding shall be
permitted.
6.0 Sampling Criteria
The sampling criteria shall be in accordance with IS :2141.
7.0 Tests on Wires before Manufacture
7.1 The wires shall be subjected to the following tests in accordance with IS :2141.
a) Ductility Test b) Tolerance on Wire Diameter
7.2 Tests on Completed Strand
The completed strand shall be tested for the following tests in accordance
with IS:2141.
a) Tensile and Elongation Test: The percentage elongation of the
stranded wire shall not be less than 6%.
b) Chemical analysis
c) Galvanizing Test
The Zinc Coating shall conform to "Heavy Coating" as laid down in 1S:4826
8.0 Marking
Each coil shall carry a metallic tag, securely attached to the inner part of the coil
bearing the following information:
a) Manufacturers name or trade mark
b) Lot number and coil number
c) Size
d) Construction
e) Tensile Designation
f) Lay
g) Coating
h) Length
i) Mass
j) ISI certification mark, if any
9.0 Packing
The wires shall be supplied in 75-100 Kg. coils. The packing should be done in
accordance with the provisions of IS:6594
10.0 Other Items:
For remaining items of stay sets mentioned in the enclosed drawing, relevant
applicable Indian standards shall be applicable.
GURANTEED TECHNICAL PARTICULARS
STAY WIRE (7/8, 7/10 & 7/12 SWG)
Sl. GENERAL TECHNICAL
No. PARTICULARS 7/8 SWG 7/10 SWG 7/12 SWG
1 Nominal diameter of wire
2 Tolerance in diameter
3 Sectional Area (In Sq. mm.)
4 Tensile strength
a Min. N/mm²
b Max. N/mm²
5 Minimum breaking load (KN)
6 Type of coating Heavy/Medium/Light
7 Variety Hard/Soft
8 Weight of Zinc coating (Gms/Sq. Mtr.)
Min.
9 No. of dips the coating is able to withstand
as 18 ± 20ºC
10 Adhesion Test (Wrap Test at 1 turn per
second coiling while stress not exceeding
% nominal tensile strength)
a Min. complete turn of wrap
b Dia of mandrel on which wrapped
11 Bend Test
a Angle
b Dia round a format to be bent
12 Freedom from defect
13 Chemical composition the MS Wire used
shall not exceed
a Sulphur 0.060%
b Phosphorous 0.065%
TECHNICAL SPECIFICATIONS
GI WIRE 6 SWG & GI WIRE 8 SWG
1. SCOPE
This specification covers manufacture, testing and supply of hot dip galvanized
MS solid wire of sizes 6 SWG (5 MM) & 8 SWG (4 MM) diameters.
2. APPLICABLE STANDARDS
02.1 ZINC
Zinc shall conform to grade Zen 98 specified in IS 209& IS: 4826-1979 with upto
date amendments.
02.2 ZINC COATING
Zinc coating shall be in accordance with IS: 4826-1979 for heavily coated hard
quality.
02.3 GALVANISING
Galvanizing shall be as per IS:2629-1966, IS 4826-1979 with up to date
amendments
02.4 UNIFORMITY OF ZINC COATING
Uniformity of zinc coating shall be as per IS:2633-1972 with up to date
amendments
02.5 TENSILE PROPERTIES
The tensile strength of the wire after galvanizing shall be between 55-95
Kg/sq.mm ensuring MS wire mechanical properties as per IS-28:1972 8.1 to 8.3.
02.6 FREEDOM FROM DEFECTS
As per IS:2629-1966 & 4826-1979 & with up to date amendments be ensured
3. MATERIAL
The mild steel wire shall have chemical composition maximum sulphur- 0.055%,
phosphorous -0.055%, Carbon 0.25%.
4. TESTS
During the process of manufacturer/fabrication and all tests for chemical,
mechanical, galvanizing as per IS-280-1979, IS1521-1972, IS-1755-1961,
IS:6745-1972 & 4826-1979 shall be carried out. The certificate towards, chemical
composition shall be submitted for each lot offered for inspection.
The following tests shall be conducted in presence of the representative of the
purchaser:
1. Visual physical inspection and measurement of specified dimension 2. Coating test as per IS:1755-1961, IS 2629-1966, IS:2633-1972, IS:4826-
1969
3. Adhesion test as per IS:1755-1961,IS:2629-1966,IS:2633-1972,IS:4826-
1969,&IS:6745-1972
4. Tensile strength and breaking load and elongation determined as per
IS:1521-1972 with up to date amendments
5. PACKING & MARKING
Packing shall be as per IS:280-1979 and each coil shall be between 50-100 kg .marking shall be as per IS:280-1972
GURANTEED TECHNICAL PARTICULARS
GI WIRE 6 SWG & GI WIRE 8 SWG
Sl.
No. GENERAL TECHNICAL PARTICULARS 6 SWG 8 SWG
1 Nominal diameter of wire
2 Tolerance in diameter
3 Sectional Area (In Sq. mm.)
4 Tensile strength
a Min. N/mm²
b Max. N/mm²
5 Minimum breaking load (KN)
6 Type of coating Heavy/Medium/Light
7 Variety Hard/Soft
8 Weight of Zinc coating (Gms/Sq. Mtr.) Min.
9 No. of dips the coating is able to withstand as 18 ±
20ºC
10 Adhesion Test (Wrap Test at 1 turn per second
coiling while stress not exceeding % nominal
tensile strength)
a Min. complete turn of wrap
b Dia of mandrel on which wrapped
11 Bend Test
a Angle
b Dia round a format to be bent
12 Freedom from defect
13 Chemical composition the MS Wire used shall not
exceed
a Sulphur 0.060%
b Phosphorous 0.065%
HT STAY INSULATOR & LT STAY INSULATORS
GURANTEED TECHNICAL PARTICULARS
(To be submitted along with offer)
Sl. Description OWNER‟s Bidder‟s Offer No. Approved
Standard
1 Manufacturer‟s name
2 Address of manufacturer
3 Location of type testing
4 Applicable standard & Type
5 Type of insulator (Porcelain or toughened
glass)
6 Dry impulse withstand voltage
7 Wet power frequency, 1 minute,
withstand voltage
8 Dry, Critical Impulse Flashover Voltage
9 Dry, power frequency, Critical Flashover
Voltage
10 Wet, power frequency, Critical Flashover
Voltage
11 Power frequency Puncture Voltage
12 Safe Working Load
13 Minimum Failing Load
14 Creepage Distance
15 Protected Creepage Distance
16 Type and Grade of Materials : Insulator
17 Colour of Insulator
18 Weight of Insulator
19 Number of Insulators per Crate
20 Type of semi conducting Glaze
21 Minimum dia of Stay wire hole
22 Whether drawing showing dimensional
details have been furnished along with
Bid
23 Whether Type Test Certificate have been
furnished
24 Other particulars (if any)
LT Distribution Box
Technical Specifications
& SCOPE
1.1 This specification covers design, manufacture, testing at manufacturer works before
dispatch and supply of L.T. Distribution Cabinet suitable for outdoor installation in Pole mounted /Plinth Mounted distribution sub-stations of following capacity.
i) L.T. Distribution Cabinet for 25KVA,63 KVA & 100KVA 11/0.433KV Transformer
1.2 The Technical Specification contained herein are for the guidance of the bidders, Any
deviation from the Purchasers specification will be considered on their relative merits from the consideration of performance, efficiency, reliability and overall economy consists with the requirements stipulated herein.
c) COMPLETENESS OF CONTRACT:
All fittings or accessories no specifically mentioned herein but necessary or usual for similar equipment and their efficient working shall be provided by the contractor without extra charges.
c) ATMOSPHERIC CONDITIONS:
a) Maximum temperature of air in shade 450C
b) Minimum temperature of air in shade 00C
c) Maximum temperature of air in sun 500C
d) Maximum humidity 100% e) Average number of thunder storm days per annum 70days f) Average number of dust storm days per annum 20 days g) Maximum rainfall per annum 2000mm h) average rainfall per annum 1500mm
i) Maximum ambient temperature daily average 450 C
j) wind pressure 200Kg/M2 k) Altitude Less than 1000m
d) DESCRIPTION OF MATERIALS
The L.T. Distribution cabinets are meant for installation in the D.P. Structure plinth Mounted/Pole Mounted Distribution 11/433 KV substation of the ratings indicated above. These Distribution Cabinets are to be outdoor type and to be fabricated out of 2 mm CR sheet steel duly acid treated and finished with one coat anticorrosive primer and two coats of gray epoxy paint. The body of the boxes shall have sufficient reinforcement with suitable size of channels keeping a provision for fixing these boxes either on DP structure or plinths.
The Box shall have double door with locking arrangement and a door handle conforming to IS 8623/1977 .The roof of the box shall be slightly slanting both sides as per drawing with an over hang of 50mm to the front and back side. For maintenance point of view doors may be provided front side as per the requirement. The nuts, bolts , washers used in the box shall be galvanized to avoid rusting. The door hinges shall not be visible from outside. The box shall have a solid earthing point and arrangement for sufficient ventilation.
The boxes should confirm to IP 54 degree of protection. The bidders shall have to enclose type test certificate for degree of protection (P-54) after their product duly tested at CPRI failing which their bid is liable for rejection. Preference
The box shall have provision of bus bars of Electrolytic Cooper mounted on epoxy resin cast bus insulators fixed on suitable fixing arrangement. The bus bars shall be conveniently placed so as to provide adequate clearance from the body of the box conforming to I.E. Rules applicable for L.T. supply. There should be heat shrinkable bus bar insulation tubing on the busbars.
The arrangement and dimensions shall be as per the drawing enclosed.
The box shall consist of one incoming MCCB and 2 sets of Kit-kat fuse unit for out going feeders.
Suitable cable glands of heavy duty, double compression type shall be provided at the bottom of the box. One for incoming cable and two/three for outgoing cables, Detachable plates shall be provided for fixing of cable glands
Sl. No. Dimension
25 KVA Dist 63 KVA Dist 100 KVA Dist
Box Box Box
1 Height of Box 700 mm 1000 mm 1000 mm 2 Length of Box 600 mm 800 mm 800 mm 3 Width of Box 400 mm 500 mm 500 mm 4 Ventilator Length 250mm 250mm 250mm 5 Ventilator Width 170mm 170mm 170mm 6 MCCB terminal 3x1/2x50 3x1/2x70 mm
2 3x1/2x 95 mm
2
suitable for mm2 cable cable cable
7 Kit Kat terminal 3x1/2x50 mm2
3x1/2x70 mm2
3x1/2x 95 mm2
suitable for cable cable cable
8 Bus Bar 25x5 mm 40x5 mm 40x6 mm 9 Bus Bar materials Electrolytic Electrolytic Electrolytic
Aluminium Aluminium Aluminium
A neutral Busbar similar to phase Busbar is to be provided.
KIT KAT FUSE UNIT : Shall be of reputed make as per IS-
2086 (make- Anchor/Havells/ Ripcon )
The kit kats should have 500 V rating. All contact parts are plated and made of copper and brass with A class porcelain with extended terminal fitted with slots hex bolts with nuts.
The outgoing terminal of the cables is to be connected to the extended terminal of the kit kat by Bimetallic lugs, duly crimped with Die less crimping tools.
MCCB OF REPUTED MAKE : (Make must be specified in the bid)
THE MCCB SHOULD CONFORM TO THE FOLLOWING
TECHNICAL SPECIFICATION
i) Standard IS 13947 (Part-2) /1993 & IEC Pub -947 -2 (1989) ii) Rated voltage 415 vol. Ac iii) No. of poles 3 iv) Utilisation category A v) Rated service short
circuit breaking capacity: The percentage of rated service short circuit breaking capacity (I.Cs) to rated ultimate circuit breaking capacity (icu)
shall be mentioned as per IS 13947 (Part- 2) /1989.
vii) Type of protection:-
Overload protection is a must with static /electro magnetic /thermo magnetic trip release.
The terminal capacity of the MCCBs should be such as to accommodate the required LT cable. The incoming cable should be connected to the terminals of the M.C.C.B. with Bi- metallic lugs preferably of Usha Martin/Dowel make duly crimped with Die press& crimping tools. There should be a metallic /heat resistant insulating barrier between the MCCB side & that of kit kat fuses so that the heat generated in Kit Kat fuses carrying current and during fuse blow should not pass to the MCCB.
d) GENERAL
The L.T. distribution Boxes should be of the dimensions as per the
details given above. The bidders can quote with their own design suitably accommodating the components in conforming to the approved clearances and technical requirement as indicated in this bid. The dimensions are only illustrative. Tolerances of dimensions are 10% over & above the dimensions specified. The bidder may specify their own dimensions within + 10% limit and quote accordingly.
The distribution boxes shall be duly wired with suitable size of PVC insulated single core copper cable or equivalent section copper/aluminum flat.
Terminal connectors for the earth connections to be provided in the box.
The distribution cabinet should be preferably of IP-54 protective category, with provision for lighting inside the cabinet. NESCO & Sl. No. Punching Marks should be given on any one of the side walls of each box as an identification of NESCO property, besides furnishing
a non-detachable name plate which should exhibit the details of L.T. Distribution Cabinet.
j) The bidders are required to furnish the Guaranteed Technical Particulars in the format given.
k) TESTS:
The M.C.C.B. to be mounted with Distribution Boxes shall have been fully type tested as per the relevant standard in any NABL approved Testing Laboratory. Copies of type test reports must be enclosed with the tender failing, which the bid is liable for rejection. Purchaser reserves the right to demand repetition of the tests without any extra cost.
l) INSPECTION: -
The inspection may be carried out by the Purchaser at any stage of manufacture. The successful bidder shall grant free access to the Purchaser’s representative at a reasonable time when the work is in progress. Inspection and acceptance of any equipment under the specification by the Purchaser shall not relieve the supplier of his obligation of furnishing equipment in accordance with the specification and shall not prevent subsequent rejection if the equipment is found to be defective.
The supplier shall keep the Purchaser informed in advance about the manufacturing programme so that arrangement can be made for inspection. The purchaser reserves the right to insist for witnessing the acceptance/routine testing of the bought out items.
2. ACCEPTANCE AND ROUTINE TESTS:-
All acceptance and routine tests as stipulated in the relevant standards shall be carried out by the supplier in presence of owner’s representative.
Immediately after finalization of the programme of type/acceptance/routine testing, the supplier shall give fifteen days advance intimation to the Purchaser to enable him to depute his representative for witnessing the tests.
3. DOCUMENTATION: -
The Bidder shall furnish following drawings along with the offer.
General outline and assembly drawing of the L.T. Distribution Box. Cross Sectional view. Arrangement of terminals & details of connection studs provided. Name plate. Schematic drawing. Type test reports MCCB & Distribution box. Test reports, literature of the bought out items and raw materials. Testing facilities available at the works. List of customers with detailed address/purchase reference, quantity and year of supply with user certificate for such items.
Guaranteed Technical Particulars of LT Dist.box
Slno. Description Bidder’s Offer
25KVA
63KVA 100KVA
1 Rated voltage & type
2 Thickness of enclosure
3 Size of Bus bar
Phase
Neutral
4 Bus bar material
5 Over all dimension of board
LXWxH
6 Bus bar supporting insulator
7 Degree of protection
8 Standard followed
9 Terminal capacity
10 Gland Size Inlet/outlet
11 Separation barrio MCCB & Kit-Kat
MCCB
12 Name of Manufacturer
13 Type/code No
14 Rated Current
15 No of Poles
16 Standard followed
17 Utilization Category
18 Rated short circuit Breaking capacity
19 Rated ultimate short circuit Breaking
capacity
20 Type of Protection provided
21 Extra Preference if any
FUSE
22 Make & voltage
23 Rating
24 Terminal Capacity
25 Wiring detail from bus bar to kit kat
fuse
D R A W I N G f o r L . T D i s t r i b u t i o n B o x f o r 25K VA 6 3 K V A , 1 0 0 K V A Transformers
N.B : Separate terminal bar to be provided for Neutral connection. LT Distribution Box for 11/0.23, 16 KVA & 11/0.4, 16 KVA DTR As per REC Specification and latest BIS
AB CABLE ACESSORIES
TECHNICAL SPECIFICATION FOR INSULATION PIERCING CONNECTORS
(IPC),CONDUCTOR DEAD END CLAMP (ANCHOR), SUSSPENSION CLAMP,NEUTRAL
CONNECTOR & EYE HOOK FOR AERIAL BUNCHED CABLES FOR WORKING VOLTAGE UPTO AND INCLUDING 1100 VOLTS SHALL BE AS PER REC SPECIFICATION
NO.32/1884 & AMMENDED NO.83 & 84 /2010 ( WHICH HAS BEEN CIRCULATED BY REC
VIDE THEIR LETTER NO.2464 & 2463 ALL DATED 11.02.2010 RESPECTIVELY OR ANY
LATEST AMMENDED.
1.0 Scope
This specification covers the design, manufacture, assembly, testing and supply of Insulation
Piercing Connectors (IPC), Suspension Clamp, Dead end Clamp, Eye hook, and Neutral connector for making connections to Aerial Bunched Cables rated 1100 volts and insulated with cross-linked
polyethylene.
2.0 Standard
The design, performance and test requirements shall confirm to this specification and the following standards. However in case of any conflict, the requirements of this specification shall prevail.
& REC Specification 32/1984
& REC Specification 83/2010( Insulation Piercing Connectors)
& REC Specification 84/2010 (dead end & Suspension clamp)
The devices shall also be compatible with the cables of sizes & dimensions as defined in the cable Specifications for the cables with which they are intended to be used.
3.0 Cable Data
The standard sizes and characteristics of the phase and street lighting conductors, bare messenger wires shall be as specified in IS: 14255-1995 and REC Specification 32/1984 of following sizes
d) 3x95 (Insulated Phase)+1x70(Bare Messenger)+1x16(Insulated street lighting) sq.mm
e) 3x50 (Insulated Phase)+1x35(Bare Messenger)+1x16(Insulated street lighting) sq.mm
f) 3x50 (Insulated Phase)+1x35(Bare Messenger) sq.mm
g) 3x50 (Insulated Phase)+1x35(Bare Messenger ) sq.mm
h) 2x50 (Insulated Phase)+1x35(Bare Messenger ) sq.mm
1
4.0 Insulation Piercing Connectors(IPC)
Insulation Piercing Connectors (IPC) are used for making Tee/Tap-off/Service connectors to an
ABC Line. Insulation Piercing Connectors are designed to make a connection between the uncut main
conductor and a branch cable conductor without having to strip either cable to expose the conductor.
Instead, the tightening action of the IPC will first pierce the Insulation, and then make good electrical
contact between the main end and branch conductor while simultaneously insulating and sealing the
connection.
The standard size ranges for various applications are given below:
Requirement Main Cable Size Branch Cable Size
range range
Insulation Piercing Connectors for 16-95 sq mm 4 - 35 sq mm
phase & Street Lighting core
4.1 Marking and Embossing
The Connector shall be indelibly marked with the following information:
Name or Logo of manufacturer
Name Purchaser, Capex, GoO
Model Number
Sizes of “Max and Min” Main and Branch cables for which it is suitable.
The permanence of the marking shall be permanent.
4.2 Type Test For all accessories, the Type Test Report should be submitted from an Independent NABL Accredited Laboratory like CPRI The installation of the connectors shall be done in the laboratory following instructions provided by the manufacturer. The Test report shall include the Model Number, Applicable size Range, and GA Drawing showing the principal parts and dimensions of the connector.
The following shall constitute Type Tests for Insulation Piercing Connectors.
d) Electrical Ageing Test
e) Dielectric and Water Tightness Test
f) Mechanical Tightening Test & Shear – head behavior
g) Effect of tightening on main core
h) Effect of tightening on branch core
Climatic test in accordance with NFC20-540
Corrosion Test in accordance with NFC 33-003
4.3. Acceptance Tests
2
The Acceptance Tests & sampling plan to be conducted as per REC Spec. 83/ 2010 and as per relevant IS Specifications.
4.4 Drawings & Samples:
GA drawing and other particulars along with samples are to be submitted along with offer.
ANCHOR (DEAD END) & SUSPENSION CLAMPS
5.0 Scope This specification covers the design, manufacture, assembly, testing and supply of Accessories for
anchoring & suspending Aerial Bunched Cables rated 1100 volts and insulated with cross-linked
polyethylene and aluminum alloy bare messenger.
Description Application
For fitting onto a pole for anchoring
a) Dead end Clamp ( as per REC the end of a length of ABC, or for a Construction standard E-35) major change in direction.
SuspensionClamp (Bolted For supporting a length of ABC at an b) Type as per REC Construction intermediate pole in a length, with standard E-34) small angle of deviation.
5.1 Cable Data The standard sizes and characteristics of the phase and street lighting conductors, messenger wires shall
be as specified in REC specification 32/1984 or IS: 14255-1995.
The strength of the messenger shall be not less than the Value shown in Table 1.
Table-1
Conductor Size Messenger Rating
(mm2.) (as per IS 14255)
35 9.8 KN
70 17.5 KN
5.2. Marking / Embossing Anchoring Clamp, Suspension clamp should bear e) Manufacturers trade mark and logo f) Purchaser, Capex, GoO
c) Product Code or Reference d) Traceability Code/Batch Number
5.3. Type Test For Dead End & Suspension clamps, the Type Test Report s should be submitted from an Independent NABL Accredited Laboratory / CPRI as per REC Spec-84/2010.
5.4 Acceptance Tests
The Acceptance Tests & sampling plan to be conducted as per REC Spec. 84/ 2010. & as per relevant IS Specifications..
5.5 Drawings & Samples:
GA drawing and other particulars along with samples are to be submitted along with offer.
6.0 EYE HOOKS
e) Eye hooks shall be as per REC construction standard E-35 (Type – A)
f) It should be made of forged hot dip galvanized steel as per IS-1570
g) The clamp corrosion resistance should conform to standards IS 2629 & IS 2633.
h) Minimum breaking Load should be 20 KN.
6.1 Type Test For Eye hooks, the Type Test Report s should be submitted from an Independent NABL Accredited Laboratory / CPRI as REC Spec-32/1984 & 84/2010 and as per relevant IS Specifications.
6.2 Acceptance Tests
The Acceptance Tests & sampling plan to be conducted as per REC Spec. 32/ 1984. & 84/2010 and as per relevant IS Specifications.
6.2 Drawings & Samples:
GA drawing and other particulars along with samples are to be submitted along with offer.
7.0 NEUTRAL CONNECTOR
b The Neutral Connector shall be as per REC Construction standard E-36 c It should be consist of corrosion resistant extruded Aluminum Alloy body suitable for
messenger wire as mentioned under clause-3 above.
7.1 Type Test For Eye hooks, the Type Test Report s should be submitted from an Independent NABL Accredited Laboratory / CPRI as REC Spec-32/1984 & 84/2010 and as per relevant IS Specifications.
.
7.2 Acceptance Tests
The Acceptance Tests & sampling plan to be conducted as per REC Spec. 32/ 1984. & 84/2010 and as per relevant IS Specifications.
7.3 Drawings & Samples:
GA drawing and other particulars along with samples are to be submitted along with offer.
GUARANTEED TECHNICAL PARTICULARS FOR INSULATION PIERSING CONNECTOR
Sl. No.
Description Guaranteed particulars to be submitted by the
Vendors along with offer
1 Name and address of the
Manufacturer
Is Manufacturer of accessories
as ISO 9001-2000
2 a) Copies of certificate enclosed b) Are GA drawing enclosed
c) Are Samples are submitted
3 Applicable standard
4 Type of connectors
5 Application
Is any metallic part carrying 6 potential in operation exposed
during installation
Are end caps of branch cable 7 a) Slide on type
b) Rigid type
8 Are torque limiting shear head
provided to tightening bolts
Range of cable sizes 9 accommodated for main and
branch
10 Min and Max torque defined
Torque for establishing 11 connection between main and
branch
12 Material used for teeth
13 Surface finish of teeth
Maximum tensile load for no
14 breakdown of main conductor(cross section)
15 Max. tensile load on branch
conductor for no break/slippage
16 Voltage withstand under water
emersion
17 No. of cycles
m) Max temp at each cycle n) Marking and embossing on the
connector
GUARANTEED TECHNICAL PARTICULARS FOR SUSPENSION CLAMP FOR BARE MESSENGER WIRE
Sl. No. Description Guaranteed particulars to be submitted by
the Vendors along with offer
1 Name and address of the manufacturer
2 Applicable standard
3 Type of clamp
4 Type of design
5 Voltage Grade(kV)
6 Loop anchor attachment(open/close)
7 Installation (with/without dis-assembly)
8 Type & grade (metallic/non-metallic
material)
9 Type of hot dip galvanizing & thickness
of Zinc coating
10 Marking
11 Colour of non-metallic parts
12 Dimensions
13 Approximate weight
14 Minimum Breaking Load (KN)
15 Maximum allowable load(KN)
16 Max. angle of deviation of conductor
(degrees)
17 Method of casting
18 Are GA drawing & samples enclosed
GUARANTEED TECHNICAL PARTICULARS FOR DEAD END CLAMP FOR BARE MESSENGER WIRE (To be submitted along with offer)
Sl.. Description Guaranteed particulars to be submitted by
the Vendors
1 Name and address of the manufacturer
2 Applicable standard
3 Type of clamp
4 Type of design
5 Voltage Grade(kV)
6 Loop anchor attachment(open/close)
7 Installation (with/without dis-assembly)
8 Type & grade (metallic/non-metallic
material)
9 Type of hot dip galvanizing & thickness
of Zinc coating
10 Marking
11 Colour of non-metallic parts
12 Dimensions
13 Approximate weight
14 Ultimate tensile strength(KN)
15 Maximum allowable load(KN)
16 Slip Strength (KN)
17 Method of casting
18 Operating temperature (deg.cent)
a) Continuous Operation
b) Short circuit condition
19 Are GA drawing & samples enclosed
GUARANTEED TECHNICAL PARTICULARS FOR NEUTRAL CONNECTOR FOR
BARE MESSENGER WIRE
Sl. No. Description Guaranteed particulars to be submitted by
the Vendors
1 Name and address of the manufacturer
2 Applicable standard
3 Type of clamp
4 Type of design
5 Voltage Grade(kV)
6 Dimensions
7 Approximate weight
8 Minimum Breaking Load (KN)
9 Maximum allowable load(KN)
10 Method of casting
Are GA drawing & samples enclosed
11
Guaranteed Technical Particulars of Eye Hook
Guaranteed Technical
Sl. No. Description Particulars submitted by
Vendors
1 Name and Address of the Manufacturer
2 Type of Hooks
3 Maximum weight span for 4x95's
Maximum weight span for 4x50's
4 Horizontal pull out load
5 Types of Facades for which it is suitable
6 Stand off from Façade
7 Method of fixing to Façade
8 Installation(with/without disassembly)
9 Type and grade of Metallic Material
10 Type of Hot Dip Galvanizing Thickness of Zinc
Coating
11 Markings:- As specified in IEC – 947
12 Dimensions
13 Net Weight
14 Ultimate tensile strength
15 Acceptance tests
MILD STEEL CHANNEL & ANGLE
Clause
No. TECHNICAL SPECIFICATIONS OF MILD STEEL CHANNEL & ANGLE
1.00.00 SCOPE
This specification covers design, manufacture, testing and dispatch to owner‟s stores of M.S. Channel & Angle for use in structures in distribution system.
2.00.00 APPLICABLE STANDARD
Materials shall conform to the latest applicable Indian standards. In case bidders offer steel section and supports conforming to any other international specifications which shall be equivalent or better than IS, the same is also acceptable.
Sl.No. Standard No. Title 1 IS: 2062 Grade „A‟ Quality Specification for M.S.Angles,
M.S.Channel 2 IS: 2062 Chemical and Physical composition of material 3 IS: 1852 Rolling and Cutting Tolerances for Hot Rolled Steel products
3.00.00 GENERAL REQUIREMENTS
3.01.00 Raw material
The Steel Sections shall be re-rolled from the BILLETS/INGOTS of tested quality as per latest version of IS:2830 or to any equivalent International Standard and shall be arranged by the bidder from their own sources. The Chemical composition and Physical properties of the finished material shall be as per the equivalent standards. Chemical Composition and Physical Properties of M.S. Angles, M.S. Channels, and M.S.Flat conforming to
IS: Conforming to IS:2062/84
3.02.00 Chemical Composition
3.03.00 Chemical composition For Fe 410 WA Grade 1 C - 0.23% MAX
2 Mn - 1.5% MAX
3 S - 0.050% MAX
4 P - 0.050% MAX
5 SI - 0.40% MAX6 CE
(Carbon Equivalent)- 0.42% MAX
3.04.00 Mechanical Properties
1. Tensile strength Kgf/mm²‾ - 410 2. Yield stress Min. for thickness/diameter < 20 mm - 26 Kgf/mm² OR 250 N/ mm² 20-40 mm - 24 Kgf/mm² OR 240 N/ mm² > 40 mm - 23 Kgf/mm² OR 230 N/ mm² 3. Elongation % - 23% 4. Bend Test (Internal Dia) - Min-3ţ (t–is the thickness of the material). 3.05.00 Tolerance
Variation in ordered quantity for any destination and overall ordered quantity be only to the extent of ±2%.
Rolling and weight tolerances shall be as per version of IS: 1852 or to any equivalent International Standard.
4.00.00 TEST
Steel Section shall be tested in IS approved Laboratory or Standard
Laboratory the Bidder country having all facilities available for conducting all the test prescribed in relevant IS or IEC or to any equivalent International
Standard or any recognized and reputable International Laboratory or Institutions.
The bidders are required to specifically indicate that;
They hold valid IS (or equivalent IEC) License. Steel Section offered are bearing requisite IS certification or equivalent marks.
The bidders are required to submit a copy of the valid IS (or equivalent IEC) License clearly indicating size and range of product against respective ISS or any equivalent International Standards along with their offer.
MARKING
5.00.00 It is desirable that the bidder should put his identification marks on the finished material. The mark shall be in “legible English letter” given with marking dies of minimum 18 mm size.
6.00.00 INSPECTION AND TEST CERTIFICATES The material to be supplied will be subject to inspection and approval by the purchaser‟s representative before dispatch and/or on arrival at the destination. Inspection before dispatch shall not however, relieve the bidder of his responsibility to supply the Steel Sections strictly in accordance with the specification. The purchaser‟s representative shall be entitled at all reasonable time during manufacture to inspect, examine and test at the bidder‟s premises the materials and workmanship of the steel section to be supplied. As soon as the steel Section are ready for testing, the bidder shall intimate the purchaser well in advance , so that action may be taken for getting the material inspected. The material shall not be dispatched unless waiver of inspection is obtained or inspected by the purchaser‟s authorized representative. Test certificates shall be in accordance with latest version of the relevant Indian Standards or any equivalent International Standard. The acceptance of any batch/lot shall in no way relieve the bidder of any of his responsibilities for meeting all the requirements of the specification and shall not prevent subsequent rejection of any item if the same is later found defective.
TECHNICAL SPECIFICATION OF INSULATORS
1. GENERAL:
This specification covers the design, manufacturing, testing, supply, delivery and performance
requirements of different types of insulators indicated in our Schedule of requirements for use in
the distribution network of SOUTHCO.
The insulators shall conform in all respects to highest standards of engineering, design,
workmanship, this specification and the latest revisions of relevant standards at the time of offer
and the Purchaser shall have the power to reject any work or material, which, in his judgment is
not in full accordance therewith.
2. SERVICE CONDITIONS:
Equipment to be supplied against the specification shall be suitable for satisfactory continuous
operation under the following tropical conditions.
a) Maximum ambient air temperature 50 ˚ C
b) Maximum daily average air temperature 40 ˚ C
c) Maximum yearly average ambient air temperature 32 ˚ C
d) Maximum temperature attainably by a body
e) Exposed to the Sum. 60 ˚ C
f) Minimum ambient air temperature -5 ˚ C
g) Maximum relative humidity 100%
h) Minimum number of rainy days per annum 70
i) Average number of rainy days per annum 120
j) Average annual rain fall 150cm.
k) Number of months of tropical monsoon conditions 4
l) Maximum wind pressure 260Kg./m2
m) Degree of exposure to atmospheric pollution normally
n) Atmosphere. Polluted.
Environmentally, the region where the work will take place includes coastal areas, subject to high relative humidity, which can give rise to condensation. Onshore winds will frequently be salt laden. On occasions, the combination of salt and condensation may create pollution conditions for outdoor materials. Therefore, outdoor material shall be designed and protected for use in exposed, heavily polluted salty corrosive and humid coastal atmosphere.
3. APPLICABLE STANDARDS:
Unless otherwise it is stipulated in this specification, the insulators shall comply with Indian standard
specification IS: 731-1971 and the insulator fittings with IS 2486(Part-I)-1971 and IS: 2486(Part-II)-
1974 or the latest version thereof.
The Bidder may propose alternative standards, provided it is demonstrated that they give a degree of quality
and performance equivalent to or better than the referenced standards. The purchaser shall adjudge whether
to accept or reject any standards. The Bidder shall furnish a copy of the alternative standard proposed along
with his bid. If the alternative standard is in a language other than English, an English translation shall be
submitted with the standard. In case of conflict the order of the precedence shall be (1) IEC or ISO standards,
(2) Indian Standards, (3) Other alternative standards. This list is not to be considered exhaustive and
reference to a particular standard or recommendation in this specification does not relieve the Contractor or
the necessity of providing the goods complying with other relevant standards or recommendation.
The insulators shall be of porcelain. These shall be non-absorbent and vitreous throughout. The
exposed surface shall be glazed. Unless otherwise it is specified, the glaze is of brown colour. The
glaze shall cover all the porcelain parts of the insulator except those areas which serve as supports
during firing or are left unglazed for the purpose of assembly. The insulators shall have adequate
mechanical strength, high degree of resistance to electrical puncture, resistance to climatic &
atmospheric conditions prevailing at site and made from one piece of moulded porcelain.
B. TECHNICAL SPECIFICATIONS OF 11 KV PIN INSULATOR
1.0 11 Kv Pin Insulators: - IS-731/77 (Porcelain Insulator for O/H power lines with nominal
voltage greater than 1000 volts.
2.0 Design and Construction
The material shall conform in all respect to the relevant Indian standards with latest amendments indicated below.
Indian Standards Title
BIS:731/1976 Porcelain insulators for overhead power lines with a nominal voltage greater than 1000V
BIS:2486 (Part-1 to Part-4) Metal fittings of insulators for overhead power lines with nominal voltage greater than 1000V
BIS:7935-1975 Porcelain insulators for overhead power lines with a nominal voltage upto and including 1000V
REC SPEC : 3/1971 11 KV Porcelain insulators and fittings
REC SPEC : 21/1981 Guy Insulator (Stay Insulator) 3.0 General Requirements for 11 KV Pin Insulators
All insulators for 11KV shall conform to Type B of latest version of IS: 731. Insulator shall be as per enclosed drawing. Pin insulator shall consist of a single piece of porcelain, intended to be mounted rigidly on supporting structure by a pin, which passes up inside the insulator. The pin type insulator shall have a top groove and shall be threaded to take mild steel pins. The profile of threads shall be as per IS: 1445.
Insulators shall confirm the following specific conditions of I.S. given below
Insulator Designation Minimum Mechanical
Failing Load Minimum Creepage
Distance
11KV Pin Insulator Type B of IS:731 10KN 320mm
Tests:
The insulators shall comply with the following tests as per IS: 731-1971.
Type tests
a) Visual examination
b) Verification of dimensions
c) Visible discharge test
d) Impulse voltage withstand test.
e) Wet power-frequency voltage withstand test.
f) Temperature cycle test.
g) Electro-mechanical failing load test.
h) Mechanical failing load test (for those of type B string insulator units to which electro mechanical failing load test (g) is not applicable.
i) Twenty four hours mechanical strength test (for string insulators only when specified by the purchaser).
j) Puncture test
k) Porosity test and
l) Galvanising test.
Acceptance Tests
The test samples after having withstood the routine tests shall be subjected to the following
acceptance test in the order indicated below:
a) Verification of dimensions.
b) Temperature cycle test.
c) Twenty four hours mechanical strength test(for string insulator units only when specified by the purchaser)
d) Electro-Mechanical failing load test.
e) Puncture test
f) Porosity test and
g) Galvanising test.
Routine Test
a) Visual examination.
b) Mechanical routine test(for string insulator units only) and
c) Electrical routine test(for string insulator units only)
Marking
Each Insulator shall be legibly and indelibly marked to show the following.
a) Name and trade mark of the manufacturer.
b) Month and year of manufacture
c) Minimum failing load in Newtons
d) Country of the manufacturer and
e) ISI Certification mark,if any. f) Specific Parameters & Layout Conditions.
4.4.2 Marking on porcelain shall be printed and shall be applied before firing.
4.5 Packing
All insulators (without fittings) shall be packed in wooden crates suitable for easy but rough handling and acceptable for rail transport. Where more than one insulator are packed in a crate, wooden separators shall be fixed between the insulators to keep individual insulators in position without movement within the crate.
TECHNICAL SPECIFICATION OF 11KV G.I.PIN
11 KV GI Pin: - Confirming to IS-2486 Part-I/1971.
a) The pins shall be of single piece obtained by the process of forging. They will not be made by any process using more than one piece of material. The pin will have good finish, free from flaws and other defects. The finish of the collar shall be such that a sharp angle between the collar and the shank is avoided. All ferrous pins, nuts and washers, except those made of stainless steel shall be galvanized by hot dip process. Other fittings, i.e flat washers and spring washers may be electro-galvanized as per IS: 2486. The threads of nuts, and toped holes, when cut after galvanization shall be well oiled or greased.
b) The pins shall be as per relevant figure indicated in IS 2486 (part II) having stalk length of 165 mm and shank length of 150 mm with minimum failing load of 10 KN with large heads and shall match with the pin type insulators with cemented zinc thimble having similar threads.
1.0 TESTS:
The pins shall be tested as per IS: 2486 (part-1):1993 Type Test:
The bidder has to enclose the reports of the following type tests carried out in any govt. recognized laboratory along with the bid documents.
a) Checking of Threads on Heads b) Galvanizing Test c) Visual Examination d) Mechanical Test.
Acceptance Tests:
Following tests shall be carried out at the works of the manufacturer before dispatch.
a) Checking of Threads on Heads
b) Galvanizing Test
c) Visual Examination
d) Mechanical Test.
Lightning Arrestor
TECHNICAL SPECIFICATION OF 11 KV LIGHTNING ARRESTOR
(VOLTAGE CLASS SURGE ARRESTORS)
The specification covers the design, manufacture, shop & laboratory testing before despatch, supply of 11
KV, Station class heavy duty, gapless metal oxide Surge Arrestors, insulating base, clamps, complete fittings
& accessories suitable for feeders including arrester's electrode earthing.
1.0 STANDARDS
The design, manufacture and performance of Surge Arrestors shall comply with IS: 3070 Part-3 and other
specific requirement stipulated in the specification Unless otherwise, specified, the equipment, material and
processes shall conform to the latest applicable Indian/International Standards as listed hereunder:
IS: 2071-1993 (Part-1): Methods of High Voltage Testing General Definitions &Test
IS: 2071-1974 (Part-2): Test Procedures
IS: 2633-1986 : Methods for Testing uniformity of zinc coated Articles.
IS: 3070-1993 (Part-3): Specification for surge arrestor for alternating current
IS:4759-1996 : Specification for hot dip zinc coating on Structural Steel
IS: 5621-1980: Hollow Insulators for use in Electrical Equipment.
IS: 6209-1982: Methods of Partial discharge measurement.
IS: 6745-1980: Methods for determination of mass of zinc coating on
IEC:TC-37 : Test Procedures.
ANSI/IEEE-C.62.11 (1982): Metal Oxide, Surge Arrestor for A.C. Power Circuits.
IEE-99-4: Surge Arrestors.
The equipment complying with any other internationally accepted standards shall also be considered if it
ensures performance equivalent to or superior to the India Standards.
2.0 GENERAL REQUIREMENT
2.1 The Metal Oxide gap less Surge Arrestor without any series or shunt gap shall be suitable for protection
of UG cable, associated equipment from voltage surges resulting from natural disturbance like lightening as
well as system disturbances.
2.2 The surge arrestor shall draw negligible current at operating voltage and at the same time offer least
resistance during the flow of surge current.
2.3 The surge arrestor shall consist of non-linear resistor elements placed in series and housed in electrical
grade porcelain housing/silicon polymeric of specified creepage distance.
2.4 The assembly shall be hermetically sealed with suitable rubber gaskets with effective sealing system
arrangement to prevent ingress of moisture.
2.5 The surge arrestor shall be provided with line suitable for cable for vertical and horizontal take off. The
earth terminals shall be provided of suitable size. The groundside terminal of surge arrestor shall be
connected with 50x6mm- galvanized strip, one end connected to the surge arrestor and second end to a
separate ground electrode (Electrode type of earthing). The contractor shall also recommend the procedure
which shall be followed in providing the ear thing/system to the Surge Arrestor.
2.6 The surge arrestor shall not operate under power frequency and temporary over voltage conditions but
under surge conditions, the surge arrestor shall change over to the conducting mode.
2.7 Surge arrestor shall have a suitable pressure relief system to avoid damage to the porcelain/silicon
polymeric housing and providing path for flow of rated fault currents in the event of arrestor failure.
2.8 The reference current of the arrestor shall be high enough to eliminate the influence of grading and stray
capacitance on the measured reference voltage.
2.9 The surge arrestor shall be thermally stable and the contractor shall furnish a copy of thermal stability test
with the bid.
2.10 The arrestors for 11 KV system shall be suitable for mounting on transformers as well as in the yard.
The supplier shall furnish the drawing indicating the dimensions, weight etc. of the surge arrestors for the
design of mounting brackets.
2.11 The arrestor shall be capable of handling terminal energy for high surges, external pollution and
transient over voltage and have low losses at operating voltage.
3.0 ARRESTOR HOUSING
3.1 The arrestor housing shall be made up of porcelain/silicon polymeric housing and shall be homogenous,
free from laminations, cavities and other flaws of imperfections that might affect the mechanical and
dielectric quality. The housing shall be uniform brown colour, free from blisters, burrs and other similar
defects. Arrestors shall be complete with insulating cases, fasteners for stacking units together and terminal
connectors.
3.2 The housing shall be so coordinated that external flashover shall not occur due to application of any
impulse or switching surge voltage upto the maximum design value for arrestor. The arrestors shall not fail
due to contamination. The 11KV arrestors housing shall be designed for pressure relief class as given in
Technical Parameters of the specification.
3.3 Sealed housing shall exhibit no measurable leakage.
4.0 TESTS
4.1 Test on Surge Arrestors
The Surge Arrestors offered shall be type tested not earlier than 5 years before the date of opening of this
tender. The surge arrestors shall be subjected to routine and acceptance tests in accordance with IS:
3070(Part3)-1993. In addition, the suitability of the Surge Arrestors shall also be established for the
following:
* Residual voltage test
* Reference voltage test
* Leakage current at M.C.O.V.
* P.D. Test
* Sealing test
* Thermal stability test
* Aging and Energy capability test
* Watt loss test
Each metal oxide block shall be tested for guaranteed specific energy capability in addition to
routine/acceptance test as per IEC/IS.
4.2 The maximum residual voltages corresponding to nominal discharge current of 10KA for steep current,
impulse residual voltage test, lightning impulse protection level and switching impulse level shall generally
conform to Annexure-K of IEC-99-4.
4.3 The bidder shall furnish the copies of the type tests and the characteristics curves between the residual
voltage and nominal discharge current of the offered surge arrestor and power frequency voltage V/s time
characteristic of the surge arrestor subsequent to impulse energy consumption as per clause 6.6 of IS: 3070
(Part-3) offered along with the bid.
4.4 The surge arrestors housing shall also be type tested and shall be subjected to routine and acceptance tests
in accordance with IS: 2071.
4.5 Galvanization Test
All Ferrous parts exposed to atmospheric condition shall have passed the type test and be subjected to routine
and acceptance test in accordance with IS: 2633 & IS: 6745.
5.0 NAME PLATE
5.1 The nameplate attached to the arrestors shall carry the following information: -
* Manufacturing Trade Mark
* Year of Manufacture
* Rated Voltage
* Continuous Operation Voltage
* Pressure relief rated current
* Name of Client-
* Purchase Order Number along with date.
6.0 INSPECTION
6.1 All tests and inspection shall be made in the manufacturer‟s works unless otherwise specifically agreed
upon by the manufacturer and purchaser at the time of placement of purchase order. The manufacturer shall
afford to the inspector representing the purchaser, al reasonable facilities, without charge to satisfy him that
the material being furnished is in accordance with these specifications. The purchaser reserves the right to get
an component/material being used by the manufacturer of the Surge Arrestor tested from any recognized test
house.
6.2 The inspection by the purchaser or his authorized representative shall not relieve the contractor of his
obligation of furnishing equipment in accordance with the specifications.
7.0 DRAWING AND INSTRUCTION MANUALS
Within 15 days of receipt of the order, the successful tenderer shall furnish to the purchaser the following
drawings and literature for approval:
a. Outline dimensional drawings of Surge Arrestor and all accessories.
b.Assembly drawings and weights of main component parts.
c. Instructions manual
d. Drawing showing details of pressure relief value
e. Volt-time characteristics of surge arrestors.
f. Detailed dimensional drawing of porcelain housing/ Silicon polymeric i.e. internal diameter, external
diameter, thickness, height profile creepage distance, dry arching distance etc.
GURANTEED TECHNICALPARTICULARSFOR
11KVLIGHTNINGARRESTOR
(To be submitted along with offer)
TECHNICAL & GUARANTEED - PARTICULARS.
12 KV 5 KA Distribution Class L.A.
Sr No.
Particulars
Requirement
To be
Specified by
the bidder
1. Type
2. Model
3. No.of Units
4. Rated voltage (KV) RMS. 12
5. Nominal Discharge current ( K Amps.) 5
6. Discharge Class Distribution
Class.
7. Reference Current ( MA) 1
8. Reference voltate (KV) > rated voltage
9. Current at MCOV.
i) Resistive current IR (Micro Amps) < 0.3 MA.
ii)Capacitive current IC ( - do-) About 1.0 MA
10. Protective ratio. 1.78
11. Maximum residual voltage for discharge
Current of 8/ 20 micro sec. Wave at.
i) 0.5 time the nominal discharge current(KV Peak) 40
ii) 1 time -do-(KV rms) 42
iii)2 times -do-(KV rms) 48
12 Maximum continous operative voltage (KV rms) 12
13 High Current impulse withstand(KA) 65
14 Energy dissipation capability (KJ/KV)
15 Insulation withstand.
i) Lightening Impulse (KV Peak) 75
ii)P.F. Dry/ Wet (KV rms) 28
16 Temporary over voltage withstand
Capability (KV Peak)
i) At 0.1 second 19
ii) At 2 Seconds 17.5
iii) At 10 Seconds 15.5
iv)At 100 Seconds 14
17 Maximum radio interference voltage PD=Less than
50 PC.
(KV rms) / partial discharge.
18 Maximum step current impulse 40
Residential voltage at nominal
Discharge current of 1 micro sec.front time(KV Peak).
19 Maximum switching impulse residual
Voltage at 50 x 100 micro sec.wave at 500 Amp.
(KV Peak)
20 Height of complete unit (mm) 250 + 15
21 Maximum recommended spacing between
Arrestor centre to centre(mm) 450
22 Clearance required from ground equipment
To various heights of arrestor unit(mm)
23 Earthign arrangement. To be
provided
24 Mounting falange dimensional details (mm) As per your
sketch.
25 Total crrepage distance (mm) 360
26 Weight of complete unit(kg.) 3.2 (Approx.)
Signature of Bidder
(This form is to be duly filled up by the bidder & submit along with the Tender)
TECHNICAL SPECIFICATION OF EARTHING COIL:
1. Qualification Criteria of Manufacturer:-
The prospective bidder may source Earthing Coil from manufacturers who must qualify all the following
requirements :
a) The manufacturer must have successfully carried out Type Test of similar item from any NABL
Accredited Laboratory within the last 5 years, prior to the date of submission of the bid.
b) The manufacturer should have supplied at least 1000 nos. to electricity supply utilities / PSUs. The bidder
should enclose Performance Certificates from the above users issued in the name of the manufacturer as
proof of successful operation in field.
2. SCOPE
The specification covers design, manufacture, testing for use in earthing of the HT poles.
3. GENERAL REQUIREMENTS
Earthing coils shall be fabricated from soft GI Wire Hot Dip Galvanized. The Hot Dip galvanized wire shall
have clean surface and shall be free from paint enamel or any other poor conducting material. The coil shall
be made as per REC constructions standard.
The Hot Dip galvanizing shall conform to IS: 2629/1966, 2633/1972 and 4826/1969 with latest amendments.
4. TESTS
Galvanizing Tests
Minimum Mass of Zinc
On GI Wire used 280 cm/m²
After Coiling-266 gm/m².The certificate from recognized laboratory shall be submitted towards mass of zinc.
Dip Test
Dip test shall stand 3 dips of 1 minute and one dip of ½ minute before coiling and 4 dips of 1 minute after
coiling as per IS: 4826/1979.
Adhesion Test
As per ISS 4826 – 1979.
5. DIMENSIONAL REQUIREMENT
Nominal dia of GI Wire -4 mm (Tolerance±2.5%)
Minimum no. of turns – 115 Nos.
External dia of Coil (Min) – 50 mm
Length of Coil (Min) – 460 mm
Free length of GI Wire at one end coil (Min.) – 2500 mm
Minimum length of wire to be grounded during installation -1000 mm.
The turns should be closely bound. Weight of one finished Earthing Coils (min.) –1.850 Kg.
EARHTING COIL
GUARANTEED TECHNICAL PARTICULARS
(To be submitted along with Offer) Sl.No. GENERAL TECHNICAL PARTICULARS BidderOffer
1 Nominal diameter of wire
2 No. of turns
3 External dia of Coil
4 Length of Coil
5 Mass of Zinc
6 Total weight of Coil
7 Whether drawing enclosed (yes)
BIDDER’S SIGNATURE WITH SEAL
(This form is to be duly filled up by the bidder & submit along with the Tender)
TECHNICAL SPECIFICATION OF 11 KV ‘V’ CROSS ARM, BACK CLAMP FOR ‘V’ CROSS
ARM:
Qualification Criteria of Manufacturer:-
The prospective bidder may source the above items from manufacturers who must qualify the following
requirements:
The manufacturer should have supplied at least 1000 no‟s (of each item) to electricity supply utilities / PSUs.
The bidder should enclose Performance Certificates from the above users issued in the name of the
manufacturer as proof of successful operation in field.
(a) Cross arms and Pole Top Brackets for 11 KV constructions at intermediate and light angle pole shall
be fabricated from grade 43A mild steel of channel section and for heavy angle poles, end poles and
section poles fabricated from grade 43A mild steel of angle section. The grades of structural steel
shall conform to IS – 226: 1975.
1. V cross arm shall be made of 75X40X6 mm MS channel for 11KV.
2. The cross arm should be hot dipped galvanized generally conformity to IS2633.72.
3. The Cross arm should be welded & jointed at any place except as specified.
4. The clamp for the cross arm shall be of GI & shall be hot dipped galvanised generally conformity to
IS2633.72.
5. The clamp should be designed to fit for the specified poles. The Back Clamp for 11 KV shall be made out
of 75 x 10 MS Flat and shall be suitably designed to fit RS Joist Pole11 Mtr long (150X150).
b)The Pole Top Bracket (F Clamp) shall be made out of 75 x 10 MS Flat suitably designed to fit RS Joist
Pole 11 Mtr long (150X150) for 11 KV.
Except where otherwise indicated all dimensions are subject to the following tolerances: Dimensions up to
and including 50mm:+1mm: and dimensions greater than 50mm:+2%
All steel members and other parts of fabricated material as delivered shall be free of warps, local
deformation, unauthorized splices, or unauthorized bends. Bending of flat strap shall be carried out cold.
Straightening shall be carried out by pressure and not by hammering.
Straightness is of particular importance if the alignment of bolt holes along a member is referred to its edges.
Holes and other provisions for field assembly shall be properly marked and cross referenced. Where required,
either by notations on the drawing or by the necessity of proper identification and fittings for field assembly,
the connection shall be match marked. A tolerance of not more than 1mm shall be permitted in the distance
between the center lines of bolt holes.
The holes may be either drilled or punched and, unless otherwise stated, shall be not more than 2mm greater
in diameter than the bolts. When assembling the components force may be used to bring the bolt holes
together (provided neither members nor holes are thereby distorted) but all force must be removed before the
bolt is inserted. Otherwise strain shall be deemed to be present and the structure may be rejected even though
it may be, in all other respects, in conformity with the specification.
The back of the inner angle irons of lap joints shall be chamfered and the ends of the members cut where
necessary and such other measures taken as will ensure that all members can be bolted together without strain
or distortion. In particular, steps shall be taken to relieve stress in cold worked steel so as to prevent the onset
of embitterment during galvanizing. Similar parts shall be interchangeable.
Shapes and plates shall be fabricated and assembled in the shop to the greatest extent practicable. Shearing
flame cutting and chipping shall be done carefully, neatly and accurately. Holes shall be cut, drilled or
punched at right angles to the surface and shall not be made or enlarged by burning. Holes shall be clean-cut
without torn or ragged edges, and burrs resulting from drilling or reaming operations shall be removed with
the proper tool.
Shapes and plates shall be fabricated to the tolerance that will permit field erection within tolerance, except
as otherwise specified. All fabrication shall be carried out in a neat and workmanlike manner so as to
facilitate cleaning, painting, galvanizing and inspection and to avoid areas in which water and other matter
can lodge. Contact surfaces at all connections shall be free of loose scale, dirt, burrs, oil and other foreign
materials that might prevent solid seating of the parts.
Shape & size
1. Cross arm shall have 2 holes of 22mm dia for 11KV for fixing of insulator. The center-center
distance between holes shall be 1070mm for 11KV & holes shall be in the middle of the top width
of cross arm.
Fixing of Cross Arms
After the erection of supports and providing guys, the cross-arms are to be mounted on the support with
necessary clamps, bolts and nuts. The practice of fixing the cross arms before the pole erection should be
followed.
GUARANTEED TECHNICAL PARTICULARS 11 KV V-CROSS ARM
Sl.No. Description Unit Bidder’s offer
1 Type of cross arm
2 Grade of steel
3 Steel standard
4 Dimensions
5 Working load(Kg)
6 Steel tensile strength (N/m²)
7 Weight of cross arm
8 Whether drawing has been submitted
with the bid
GUARANTEED TECHNICAL PARTICULARS BACK CLAMP FOR ‘V’ CROSS ARM
Sl.No. Description Unit Bidder’s offer
1 Type of cross arm
2 Grade of steel
3 Steel standard
4 Dimensions
5 Working load(Kg)
6 Steel tensile strength (N/m²)
7 Weight of cross arm
8 Whether drawing has been submitted with the bid
GUARANTEED TECHNICAL PARTICULARS FOR F-CLAMP
SL No
Name of the Particulars Desired
Bidder’s Offer Value
1 Type of crossarm
2 Grade of steel
3 Steel standard
4 Fabrication Standard
5 Dimensions Mm
6 Steel section utilized
7 Steel tensile strength N/cm2
8 Working load Kg
Details of galvanizing method utilized a n d
9 s t a n d a r d / s p e c i f i c a t i o n conforming
TECHNICAL SPECIFICATION FOR 11 KV 45 KN DISC
INSULATORS
6. SCOPE :
This specification covers the manufacture, testing and works supply and delivery of 11 KV Disc
insulators. The Porcelain insulators shall conform to IS:731-1971ammended upto date.
Insulators shall be of Tongue & Clevis type (T&C).Disc insulators made of glazed porcelain
shall be used as insulators on dead ends or on suspension type lines of 11 KV and above.
Tongue & Clevis type (T & C) disc insulators of mechanical strength not less than 45KN shall
be used confirming to IS: 731/1971. These shall be mounted on metallic cross-arms with the
help of suitable non-magnetic galvanised iron hardware fittings. Small fittings like spring
washers, nuts etc may be electro-galvanised.
7. SERVICE CONDITIONS :
The insulators to be supplied against this specification shall be suitable for
satisfactory continuous operation under the following tropical conditions.
2.1.1 Maximum ambient temperature (Degree C) … 50
2.1.2 Minimum ambient temperature (Degree C) … 3.5
2.1.3 Relative Humidity (%) … 10 to 100
2.1.4 Maximum Annual Rainfall (mm) … 1450
2.1.5. Maximum Wind pressure (kg/m.sq.) … 150
2.1.6 Maximum wind velocity (km/hour) … 45
2.1.7 Maximum altitude above mean sea level (meter) … 1000
2.1.8 Isoceraunic level (days/year) … 50
2.1.9 Seismic level (Horizontal acceleration) … 0.3 g
2.1.10 Moderately hot and humid tropical climate
conductive to rust and fungus growth
3. System Particulars :
a) Nominal System Voltage 11 KV
b) Corresponding highest system Voltage 12 KV
c) Frequency 50 Hz with 3% tolerance
d) Number of phase 3
e) Neutral earthing effectively grounded.
f) Min. Impulse withstand voltage 75 KV
18. Standards :
Unless otherwise specified elsewhere in the specifications insulators shall confirm to the
latest revisions of all relevant standards .
(a) General Requirements
to?
10 Weight of cross arm kg
11 Whether drawing has been submitted with the bid
The Porcelain insulators shall generally conform to IS:731-1971 and any amendments up
to date to the same .
21. Conductors :
The Disc Insulators will be used on lines on which the conductors will be A.A.A.
Conductor of size up to 100 sq. mm. The insulators should withstand the conductor
tension, the reversible wind load as well as the high frequency vibrations due to wind.
a) Type
1. Insulator shall be suitable for both the suspension and strain type of load & shall be of
Tongue and Clevis type. The insulators shall conform to Type „B‟ of IS:731-1971.
2. Diameter of porcelain disc insulator shall be 255mm . The center to center distance
between Tongue and Clevis shall be 145mm.
3. Insulator Ends.
Disc Insulators shall have Tongue and Cleave ends. The security clips will have to be
provided as per fig. 25 of I.S. 2486 (Part-2) 1989 ( amended up to date) REC Specification
3/1971(Revised 1993).
1. The colour of the units shall be brown for 45 KN Disc Insulators .
2. The number of units to be used both on suspension and tension strings shall be as given below
:
Voltage Class Suspension Strings Tension Strings.
Single Double Single Double
33 3 3x2 3 3x2
22 2 2x2 2 2x2
11 1 1x2 1 1x2
iv). Electromechanical & Mechanical Strength :
The mechanical and electromechanical strength of the individual and the complete Disc
shall be 45 KN.
22. Creepage Distances :
The minimum creepage distance for each 11KV disc Insulator shall 320mm.
6.0 Tests : Suitable number of individual units and complete string shall be subject to the
following tests in accordance with IS:731/1971 with its latest amendments.
24. Type Tests :
Following Type test shall be carried out on porcelain insulators as specified in IS: /971 amended up to date.
Visual Examination. Verification of dimensions. Visible Discharge Test.
Impulse voltage withstand test.
Impulse voltage flashover test. Wet one Minute Power Frequency withstand test and West Flashover test.
Temperature Cycle test. Electromechanical failing load test.
Power frequency puncture withstand test. Porosity test. Galvanizing test.
12. Acceptance Tests :
The test samples after having withstood the routine test shall be subject to
the following acceptance tests in order indicated below:
Verification of dimensions. Temperature Cycle test.
Twenty four hour mechanical test.
Electromechanical failing load test.
Power Frequency puncture withstand test. Porosity test.
Galvanizing test.
18. Routine Tests:
1.Visual Examination
2. Mechanical test
3. Electrical test
4. Twenty four hours mechanical test
5. Electro mechanical failing load test
7 Test Certificate :
The tenderer shall furnish detailed type test reports of the offered Disc Insulators as per
clause 6.1 of the Technical Specifications at the NABL approved laboratories to prove that
the Disc Insulators offered meet the requirements of the specification. These Type Tests
should have been carried out within five years prior to the date of opening of this tender.
i) Their offered Disc Insulators are already fully type tested at approved Laboratory
CPRI/NABL within five years prior to the date of opening of this tender.
ii) There is no change in the design of type tested Disc Insulators and those
offers against this tender.
iii) Such tenderers complying (i) and (ii) above shall furnish an undertaking in the
format schedule.
The purchaser reserves right to demand repetition of some or all the Type Test in
presence of purchaser‟s representative at purchaser‟s cost. For this purpose, the tenderer
shall quote unit rates for carrying out each Type Test. However, such unit rates will not be
considered for evaluation of the offer. In case the unit fails in the Type Tests, the complete
supply shall be rejected.
8. Testing Facilities :
The tenderer must clearly indicate what testing facilities are available in the works of the
manufacturer and whether facilities are adequate to carry out all Routine & acceptance
Tests. These facilities should be available to Board's Engineers if deputed or carry out or
witness the tests in the manufacturer works. If any test cannot be carried out at the manufacturer's work, the reasons should be clearly stated in the tender. The
insulators shall be tested in accordance with the procedure detailed in IS-731/1971
amended up to date.
9. Material Quality and Workmanship :
The quality of porcelain and hardware in case of porcelain insulators and core & housing in
case of polymeric insulators shall be of the highest grade and best workmanship such as is
suitable and customary for extra high tension lines and shall conform to current IS or IEC
(only in absence of the relevant I.S.S.). The porcelain shall be sound, free from defect, thoroughly vitrified and smoothly glazed
and brown in colour.
Unless otherwise specified the glaze shall cover all exposed porcelain parts of the insulator.
Glazing shall be uniform and free from defects. Small and the
insulator glaze of a total surface less than 0.5 sq.cm. ignored.
Deviation on this account may be supported by relevant IS.
isolated defects in
will however be
10 Mechanical Design :
The design shall be such that stresses due to expansion and contraction in any part of
insulator shall not lead to deterioration.
Cement used in manufacture of the insulators shall not cause fracture due to expansion or
loosening due to contraction.
11. Drawings :
The tender shall be accompanied with the detailed drawings showing the dimensions of the individual Disc giving all the design dimensions of various component parts. The
drawing for Insulators should clearly show the method of cementing the porcelain to the
metal caps and balls. Generally it shall be as per IS.
12. Markings:
12.1 Each insulator shall be legibly and indelibly marked to show the following : a) Name or trade mark of the manufacturer. b)
Voltage Type
d) Month and year of manufacturing.
d) Electromechanical strength in KN e)
Property of NESCO.
12.2 The “W” clip shall be marked with/punched with the ball and socket sizes for which it is
meant e.g.16B,20 etc.
12.3 Marking on porcelain shall be printed and shall be applied before firing.
13 Packing :
All insulators shall be packed in crates or boxes suitable for rough handling. Packing
shall be marked with the strength and KV rating.
GUARANTEED TECHNICAL PARTICULARS FOR 45 KN DISC. INSULATOR ( T&C TYPE)
Sl. Particulars
Specific Bidders offer
No
Requirement
1. Name of Manufacturer. & Address To be specified by the
bidder
2. Location of type testing To be specified by
the bidder
3 Applicable standard IS-731/1971 with
latest amendment
4 Type of insulator T&C type Disc insulator
5 Nominal System Voltage 11 KV
6 Highest System voltage 12 KV
7 Visible discharge Test voltage (Minimum) 9 KV
8 Dry Impulse withstand voltage +(1.2/50 microsecond wave) 75 KV
9 Dry Impulse flashover voltage+(1.2/50 microsecond wave) 90 KV
10. Dry 1 min. power frequency withstand Voltage kV. 60 KV
11 Wet 1 min. power frequency withstand Voltage . 35 KV
12 1 min. power frequency flashover Voltage kV. (Dry) 65 KV
13. 1 min. power frequency flashover Voltage kV.(Wet) 45KV
14 Power frequency puncture voltage 105 KV
15 Mechanical Routine test load 18 KN
16 Mechanical impact strength 45 KN
17 Shattered strengths (Glass) .. KV
18 Electromechanical Failing Load 45 KN
19 Safe working load 18 KN
20 Minimum Failing Load 45 KN
21 Creepage Distance 320 mm
22 Type and Grade of Materials :
i) Insulators Porcelain
ii) Cap Malleable Casting or S.G
iii) Pin Forged pin
iv) Locking Split pin
v) Cement Portland
23 Type of semi conducting Glaze Ceramic
24 Colour of Insulators Dark Brown
25 Weight of single disc. kg. 4 Kg(Approx.)
26 Number of Insulators per crate 4 nos./ 6 nos.
27 Cross weight of Loaded crate 20 – 30 Kg
28 Whether drawing showing dimensional details have To be enclosed by
been furnished along with bid. bidder
NB : Every insulator should bear the marking of Purchaser’s name/ Manufacturer’s name
and ISI mark.
TECHNICAL SPECIFICATION
11KV H.W fittings (T&C Type) : 11 KV Hard Ware fittings Tongue & Clevis type ,confirming to REC Construction Standard C-2 and as per
drawing.
T & C Hardware Fittings
The hardware fittings for B & S and T & C Strain Disc Insulator. For use in 33 KV and 11 KV
Overhead power lines shall comply IS:2486 (Part-I) 1971 and 2486 (Part-II) / 1974 and IS:2486 (Part-III) 1974 IS:12048 /1987 and REC Specification 24/84 or the latest revision
thereof. All Forging and Casting shall be good finish and free from flaws and other defects. The edges on
the outside of fittings such as at the Eye, Cleaves and Holes shall be rounded.
All parts of different fittings, which provide for Inter-connection shall be made such that sufficient clearance is provided at the Connection Point to ensure free movement & suspension of the Insulator string Assembly.All eye and cleaves shall be free in this manner but care shall
be taken that too much clearance between Eye & Tongs of the cleaves is avoided. All ferrous fittings and parts other than those of Stainless steel shall be hot dip
galvanized as per ISS: 2633 / 1964.Small fittings like Spring washer , Nuts etc. may be Electro- galvanized as per IS-6745 / 72.The threads of nuts and topped holes when cut after
Galvanizing shall be well cited & grassed.
Tongue & Clevics type Hardware Fittings (Conventional / ¼ Performed ) for T & C type
Strain Insulators
The Hardware fittings ( Tongue & Clevis type) shall be suitable for fixing on 75 mmx40 mm
Channel Cross Arm an accommodation 55mm²/80 mm² /100mm² Conductors. The set shall comply
of the following components :- e) Cross arms straps (Dead & Straps) with Bolt (16mm) Nut and Spring Washer.
f) Two Nos. forged cotter pints and spring washer to suit the tongue and the clevics. (iii)
Formed helical fittings should be of suitable materials i.e all alloy aluminum steel suitable
for 34mm²/55mm²/100mm² ACSR/AAAC. (iv)
Strain clamps shall be suitable for the above ACSR conductor or
AAAC.The ultimate strength of the clamp should not be less than
3000 Kg and slipping strength shall not be less than 90% of this
figure.The clamp should be malleable cast iron/All alloy A-6.
Tests : String insulator fittings shall comply with the following tests as per IS: 2486 (Part.I)
Type Tests: a) Visual examination test
i) Verification of dimensions iii) Slip
strength test d Mechanical test e Electrical resistance test vi)
Heating cycle test o) Galvanising test.
Acceptance/ Routine Test : i)Verification of dimensions ii)
Mechanical test 4. Galvanising test
5. Vidual examination test v) Routine mechanical test.
Marking : The caps and clamps shall have marked on them as trade mark & year of manufacturing.
Packing :
All hardware fittings shall be packed in bags or boxes suitable for rough handling. Packing shall be
marked with the strength and KV rating.
Guaranteed Technical Particulars :
The bidders are required to furnish the guaranteed technical particulars duly filed in the
proforma along with the bid.
v
Sl.No. Description Specified Bidders Offer
1. Manufacturer Name & To be specified by Bidder
Address
2. Standard Specification to IS: 2486 (Part-I,II &II)
which Hard ware Fittings
shall confirm.
3 Ultimate strength 3000 Kg (min)
4. Dimensions in accordance IS: 2486(Part-II)
with
5 Type of washer thickness
a) Spring 2.5 mm
b)Flat 2.5 mm
6. Type of Clamp size Tension Clamp suitable for
Squiral/Weasel/ Rabbit 7. Galvanised conform to IS 2633 , IS: 4759-1996 &
IS: 6747
8. Weight of Fittings ..
9. Tolerance in dimension if + 5%
any 10. Manufacturer trade mark to be Specified by the Bidder
embossed on the sets
11. Specific drawing to be Enclosed
enclosed. NB. All ferrous fittings and the parts other than those of stainless steel , shall be
galvanized.
Name & Signature of Bidder with seal
TECHNICAL SPECIFICATION
(For supply of LT XLPE AB Cables)
Part-1:
1.
SCOPE: This specification covers the design, manufacturing, testing, supply, delivery and performance
requirements of LV overhead ISI marked Aerial Bunched Cable (ABC) of different sizes indicated in
our Schedule of Requirements for use in the LV network of SOUTHCO
The materials offered shall have been successfully type tested and the design shall have been in
satisfactory operation for a period of not less than two years on the date of bid opening. Compliance
shall be demonstrated by submitting with the bid (i) authenticated copies of the type test reports and
(ii) performance certificates from the users.
However where the bidder offers similar but not identical material but higher size to that which has
been type tested, the difference shall be stated in Test Certificate Schedule. The purchaser shall
adjudge whether to accept or reject the offered material and type test data presented.
The scope of supply includes the provision of type tests. Rates for type tests shall be given in the
appropriate price schedule of the bidding document and shall be considered for evaluation. The
purchaser reserves the right to waive type tests as indicated in the section on Quality Assurance,
Inspection and Testing in this specification.
The Aerial Bunched Cable shall conform in all respects to highest standards of engineering, design,
workmanship, this specification and the latest revisions of relevant standards at the time of offer and
the Purchaser shall have the power to reject any work or material, which, in his judgment is not in full
accordance therewith.
2. STANDARDS:
Except where modified by this specification, the Aerial Bunched Cable shall be
designed, manufactured and tested in accordance with the latest editions of the following standards.
IES/ISO IEC: 1089 ISO: 9000
IEC: 502
Indian Standard IS: 398/1994
IS: 398(Part-4)/1994
IS: 8130/1984 IS: 10810/1984
IS:7098/1998
IS:14255/1995
Material
Round wire concentric lay
Overhead electrical
Stranded Conductors.
All Aluminum Alloy
Conductors, Quality
Management Systems.
Conductors for insulated
Electric cables.
Method of Tests for cables.
XLPE Insulated PVC.
Sheathed power cables.
Aerial Bunched Cables for
working voltage up to and
including 1100 volts.
The Bidder may propose alternative standards, provided it is demonstrated that they give a degree of
quality and performance equivalent to or better than the referenced standards. The purchaser shall
adjudge whether to accept or reject any standards.
The Bidder shall furnish a copy of the alternative standard proposed along with his
bid. If the alternative standard is in a language other than English, an English translation shall be
submitted with the standard.
In case of conflict the order of the precedence shall be (1) IEC or ISO standards, (2)
Indian Standards, (3) Other alternative standards. This list is not to be considered exhaustive and
reference to a particular standard or recommendation in this specification does not relieve the
Contractor or the necessity of providing the goods complying with other relevant standards or
recommendation.
3.0 SERVICE CONDITIONS:
The service conditions shall be as follows:
Maximum altitude above sea level Maximum ambient air temperature Maximum daily average ambient air temperature Maximum ambient air temperature Maximum temperature attainable by an object exposed to sun Maximum yearly weighted average ambient temperature Maximum relative humidity Average number of thunderstorm days per annum Average number of rainy days per annum Average annual rainfall Wind pressure as per IS:5613(Part-I/Sec.I) 1985
500m 500C 350C 5 0C 600C 320C 100% 70 120 150cm
Wind Zones Light Medium Heavy
IS:5613 Part-I/Sec-I Terrain Category 100 Kg/m2 150 Kg/m2 200 Kg/m2
Environmentally, the region where the work will take place includes coastal areas,
subject to high relative humidity, which can give rise to condensation. Onshore winds will frequently
be salt laden. On occasions, the combination of salt and condensation may create pollution conditions
for outdoor insulators.
Therefore, outdoor material shall be designed and protected for use in exposed, heavily polluted salty
corrosive and humid coastal atmosphere.
4. SYSTEM CONDITIONS:
The materials shall be suitable for installation in supply systems of the following characteristics.
Frequency Nominal System Voltage Maximum System Voltage LV System Minimum LV Voltage Power frequency one minute withstand (set & dry) Neutral Earthing arrangement LV System
50Hz 400/230V 440/250 V 370 V 2KV
Solidly earthed
5.0
Part-2: TECHNICAL
GENERAL/ TECHNICAL The design of Aerial Bunched Cable offered shall comprise a compacted, standard,
hard drawn H2 / H4 grade aluminum phase conductor as applicable under IS-8130
/ 84 with cross linked polyethylene (XLPE) insulation 0.65 to 1.1. KV class, having of
carbon black content 2.5% ± 0.5%.
The sizes and number of cores required are:
3x50mm2 + 1x16mm2 + 1x35mm2 (catenaries type)
3x35mm2 + 1x16mm2 + 1x25mm2 ( catenaries type)
3x35mm2 + 1x25mm2
1x35mm2 + 1x25mm2
The type of Bunched Cables shall be three phase and street lighting insulated
bundled. All Aluminum Conductors combined with a neutral and catenaries (bare) which shall be of
heat treated aluminum magnesium silicon alloy wires containing approximately 0.5% each of
magnesium and silicon respectively. The catenaries must have an ultimate tensile stress of not less
than that specified in the table of technical requirements.
The Bidder shall specify the standard to which this bundle shall be manufactured.
The conductor bundle offered shall be designed to meet the requirements set out in
this specification taking note of safety factors pertaining to conductor or catenary tensioning and
NESC specification: General Technical Requirements for LV overhead lines.
However, a bid of Aerial Bunched Cables shall not be considered, unless it is
accompanied by a list of all special tools and equipments necessary to complete the installation.
6.0 CONDUCTORS:
(a) The phase & street light conductors shall be of multi -stranded aluminum of compacted
circular cross section. The aluminum shall comply with IS 8130:1984. The messenger
conductor shall be of multi-stranded Aluminum Alloy conforming to IS 398 ( Part 4 ) - 1994.
In addition to meeting all requirement of relevant ISS the LT XLPE AB Cables supplied shall
satisfy following general requirements.
FOR PHASE AND STREET LIGHT CONDUCTORS
Minimum. Over all dia.
Sl. No.
1
2
3
4
5
6
Specified Cross
Sectional Area (mm2)
16
25
35
50
70
95
No. of Stran ds
7
7
7
7 19
19
Minimum Dia Of each
strand in mm
1.75
2.14
2.54
3.05
2.18
2.54
Of conducting
part of the
compacted
conductor. (mm) 5.25 6.42 7.6
9.15
10.9
12.7
Maxm. D.C Registance at 20
degree centigrade.( Ohm / Km)
AS PER ISS / GTP
Nominal Insulation
thickness (mm)
1.2
1.2
1.2
1.5
1.5
1.5
FOR MESSANGER CONDUCTORS
Sl. No.
1
2
3
4
Phase Conductor Size of the
LT AB Cable in
mm2
16
50
70
95
Specified Cross
Sectional Area of the
Messanger
Conductor (mm2)
25
35
50
70
No. of Strands
7
7
7
7
Nominal
dia Of each
strand
2.14
2.54
3.05 3.6
Appx. Over all dia. Of
conducting
part of the
compacted
conductor. (mm)
5.2
7.6 9.15
10.8
Maxm. D.C Resistance of
the messenger at
20 degree centigrade.( Ohm / Km)
AS PER
ISS/GTP
Appx. Mass ( Kg / Km.)
for
the messanger
65
95 136
191.8
6.0 (b) The bidder must take required precaution to ensure that the average diameter of each
strand of conductor shall be ascertained through physical measurement of dimensions of finished
cables at ambient temperature during pre-dispatch inspection or / and verification at NESCO,
WESCO & SOUTHCO Store by consignee and the value so obtained shall have a tolerance limit
with reference to the nominal diameter of each strand of conductor as stated in the tables above.
7.0
8.0
TOLERANCES: The measurement of strand diameter of the finished AB Cable shall not be less
0.03mm for strands up to and including 3.00mm diameter. For strands above that size, measurement
of strand diameter shall not be less than 1% of the nominal strand diameter.
For the purpose of checking compliance with the above requirement, the diameter
shall be determined by two measurements at right angles taken at the same cross section. The
physical measurement of strands shall be conducted after opening the strands of a finished AB Cable
offered for inspection.
SPLICES IN WIRES:
Splices in Wires shall generally comply with requirements of IEC 1089. The aluminum alloy rods may be spliced by cold pressure but welding before drawing
provided the manufacturer can guarantee that the splice can develop 90% of the tensile strength of
the un sliced rod. Wires which break during stranding may be
sliced by cold pressure butt-welding provided that:
No two splices in the completed conductor occur within 15m of each other and no two
splices in any individual wire are less than 150m apart.
The splice shall be done with high skilled workmanship. The finished splice shall be
smooth and at no point shall the cross sectional area be less than that of the un sliced wire.
Splicing of the alloy wires on the stranding machine in order to utilize lengths of wires
on reels shall not be permitted.
9.0
10.0
11.0
STRANDING AND CORE LAY: The conductor cores shall be stranded and the direction of lay must be as defined in IEC: 1089. INSULATION: The Aerial Bunched Cables shall be insulated for a voltage class of 0.65/1.1 KV and
shall be capable of operating permanently at 1.2KV.
The insulation wall thickness shall be determined in accordance with Table-4 (Clause-
7.2 and Clause 7.3) of IS: 14255/1995.
The insulating material shall be black and suitable to resist ultra violet radiation, salt
laden sprays, chemical pollution, ageing effects, abrasion and mechanical shocks and
mechanical and electrical stress at temperature up to 90˚C in normal operation and
2500C under short circuit conditions per IEC: 502/1994.
The carbon black content in the XLPE insulation shall be 2.5% ± 0.5%
PHASE IDENTIFICATION: The individual insulated conductors within a bundle shall be identified by means of
longitudinal projections.
The three phase conductors shall be marked by one, two or three longitudinal
projections, indicating the red, yellow and blue phases.
The projections shall have the following dimensions.
The distance between the tips of two adjacent projections, where there is more
than one, shall be between 1.0 and 1.5.
The width of the projection at the base shall be 1.0mm; and
The height of the projections shall be 0.5mm.
12.0
INSULATION MARKINGS: Each individual conductor comprising a bundle shall have the range of non-erasable
distinct markings listed below legibly printed on the insulation surface at one meter intervals. The
embossing should be very clear & easily visible to naked eye.
ISI Mark, IS 14255-95, Manufacturer‟s B.I.S License No. legibly embossed on
the insulation.
Name of the Purchaser.
P.O No. & Date
Manufacturer‟s trademark identification for example "UCXLPE50"
Year of manufacture: last two digits are sufficient:
Designation of conductor type
Size: for example "3x50"
Shape of conductor.
Rated voltage class: 0.65/1.1KV
Back up conductor identification: conductors with one, two and three
projections shall be marked R, Y and B respectively. The conductor with no
projection shall be marked N and
The height of the printed lettering shall be not less than 20% of the overall
diameter of the conductor
The markings shall be made in the sequence indicated above.
Thus if the manufacturer were XY, the aerial bunched cable had been manufactured in 1994, size
3x50mm2 + 1x35mm2 + 1x16mm2 with conductors of circular cross section and with a bundle of the
self supporting type, manufactured to a recognized
international standard then the core with two projections would be marked as follows:
XY-04-NFA4X50+1X16-r-m-0.65/1.1KV-Y Where, N is the international standard, F indicates overhead cable, A is aluminum
alloy conductor and 2X refers to XLPE insulation, „r‟ means round core, „m‟ self-
supporting and „y‟ the phase identification.
13.0 14.0
15.0 15.1
15.2
TWIST: The direction of lay of the conductors comprising the bundle shall be left -handed and
the lay ration shall comply with IEC: 1089.
With a bare catenaries configuration the insulated phase cables together with the
street lighting cores shall be twisted round the neutral catenaries to form the ABC. This cable bundle
is then strung directly onto the distribution poles supported by the catenaries with standard approved
hardware.
CABLE DRUM LENGTH: The cable shall be supplied in 500m . Drum Lengths as the case may be for different
sizes of LT XLPE AB Cable.
TESTS:
General
Where not specified, all tests and test results shall conform to the requirements of IEC
502/1994 or IS 7098 (Part-I) 1998, IS 10810/1984, IS: 398(Part-IV) and IS:
14255/1955.
Unless expressly stated otherwise, the ambient temperature for routine tests as well as
voltage tests shall be 20 + 150C and for all other tests be 20 + 150C.
The frequency of the alternating test voltage shall be 49 Hz to 51Hz. The voltage wave
form should be sinusoidal.
Type Tests The test sample shall be 10m to 15m in length. All cores of the bundles shall be
tested.
Insulation resistance at ambient temperature.
Insulation resistance at operating temperature.
AC voltage test.
The insulation resistance test at ambient temperature shall be carried out in a water
bath at ambient temperature.
The insulation resistance test at a operating temperature shall be conducted in a
water bath at 900C.
The longitudinal projections used for phase identification shall be ignored. The results
of this test shall be used to calculate the volume receptivity and the results conform to the
requirements of IEC:502/1994 or IS 10810 (Part-43).
The AC voltage test shall be carried out by applying 1.95KV (3U0) for four hours to the
sample, which shall be submerged in a water bath at ambient temperature, having been steeped for a
period not less than one hour. The test shall only be deemed to have been passed if no breakdown
occurs.
Furthermore, the following non-electrical type tests shall also be carried out:
Insulation wall thickness: the longitudinal projections used for phase 1
identifications shall be ignored as per IS 10810 (Part-6);
Ageing test, consisting of an evaluation of the retention of the mechanical
properties of the insulation after ageing.
Wrapping test: as per IS 10810 (Part-3);
Tests for bleeding and blooming of pigment as per IS 10810 (Part-9)
Thermal expansion of insulation.
Measurement of carbon black content as per IS 10810 (Part-32).
Water absorption by the XLPE insulation, shrinking of the XLPE insulation.
Tensile test: adhesion between conductor and insulation.
The adhesion test requires a tensile testing machine. A sample of at least 300mm
length shall be selected and straightened out. The insulation shall be removed for a l ength of 150mm.
The insulated end shall be held in the upper grip head and the bare conductor on the lower grip head.
Tension shall be applied at a speed of 500mm/ min until the conductor first begins to slide within the
insulation. The test shall have been passed if the conductor and insulation combination can stand
75N/mm2 without slippage occurring.
The neutral conductor/catenaries shall be type tested in accordance with the
requirements of IS 398 (Part-IV) 1994.
15.3 15.4
Routine Tests The following measurement or tests shall be carried out on all drums and coils of
Bunched cable:
Conductor resistance
Voltage test.
The conductor to be tested for conductor resistance shall be stored for at least 12
hours in a room at particular constant temperature. If it cannot be established that the conductors
have reached the room temperature, the test should be postponed for a period of further 12 hours.
Alternatively, the test can be carried out on short sample after remaining one hour in a temperature
controlled water bath. The test shall be carried out and the conversion factors used to convert the
resistance value to a base of 2000C and one Km. The DC resistance of each conductor shall not
exceed the appropriate maximum values specified in IEC:228/IS:6474.
The voltage test shall be conducted by applying to each core 3.5KV AC (2.5 U 0 plus 2
KV) or 8.4 KV DC for 5 minutes with the specimen lying in a water bath at ambient
temperature. The conductor shall pass the test if no electrical breakdown occurs.
Acceptance Tests
The following sample check, measurements and test shall be carried out in addition to
the Acceptance Tests as per IS 14255 - 1955, IS : 398 ( Part - IV ) 1994, IS 8130 / 1984
Measurement of insulation wall thickness;
Measurement of diameter of each strand, overall outside dia & Cross Sectional
Area of the conducting Part out of the finished product during pre-dispatch inspection.
Thermal expansion test;
Check of physical characteristics
Tensile strength of individual wires of conductor.
High Voltage Test on drums immersed in water(apply voltage 3.5 KV AC for 5 min)
These tests should be carried out on one length form each production batch of the
same sample.
The thickness of the insulation wall shall be measured on a piece removed from each
end of the sample length. If either means or minimum values are not met, two further samples shall be
removed at 0.5m form the end corresponding to the failed specimen. If these samples do not satisfy
the mean and minimum thickness requirements, the test shall be deemed to have been failed.
The longitudinal projections used for phase identifications shall be ignored.
The thermal expansion test need only be carried out on one core.
In relation to the tensile test, the tensile strength of the aluminum wires before
stranding and that of the finished conductor shall comply with IEC:1089.
15.5
15.6
Test on the Catenary (messenger) Conductor Breaking load, elongation and resistance tests shall be completed on the aluminum
alloy catenaries conductor in accordance with the requirements of IS:398 (Part - IV)/1994 or
IEC:1089.
Bending Test on a complete cable This test shall be performed on a sample of completed cable. The sample shall be bent
around a test mandrel at room temperature for at least on turn. It shall then be unwound and the
process shall be repeated after turning the cable sample around its axis by 180 0. This process shall be
repeated twice more. There shall be no signs of breaking or cracking of the cable insulation during
this test.
The diameter of the mandrel shall be:
10 (D+d)
15.7
16.0
17.0 18.0
19.0
Where D = Actual diameter of the cable (mm)
d = Actual diameter of the conductor (mm)
Rejection and Retests Should any one of the test pieces first selected fail to pass the tests, two further
samples from the same batch shall be selected for testing, one of which shall be from the length from
which the original test sample was taken unless the length has been withdrawn by the supplier.
Should the test pieces from both of these additional samples satisfy the requirements
of the tests, the batch represented by these samples shall be deemed to comply with the standard.
Should the test pieces from either of the two additional samples fail, the batch represented shall be
deemed to have failed.
COMPLIANCE WITH SPECIFICATION:
The Aerial Bunched Cable shall comply in all respects with the requirements of this
specification. However, any minor departure from the provisions of the specification shall be
disclosed at the time of bidding in the Non-compliance Schedule of this document.
COMPLIANCE WITH REGULATIONS:
All the cables shall comply in all respects with the Indian Regulations and Acts in
force. The cables and connections shall be designed and arranged to minimize the risk of fire and any
damage, which might be caused in the event of fire.
Non-conforming Product
The Purchaser reserves the right for decisions regarding acceptance, modification or
rejection of non-conforming items.
Inspection and Testing The Purchaser or his authorized representative has free entry at all times, while work
on the contract is being performed, to all parts of the manufacturer‟s works which
concerns the processing of the cables ordered. The manufacturer shall afford the the
purchaser or his authorized representatives without charge, all reasonable facilities to
ensure that the cable being furnished is in accordance with these specifications.
The cables shall successfully pass all the type tests, routine tests & acceptance Tests
referred to in the section on tests and those listed in the most recent edition of the standards given in
the specification.
The Purchaser reserves the right to reject any of the cables if the test results do not
comply with the values specified or with the date given in the Technical data schedule.
Type tests shall be carried out at an independent testing laboratory or at the
manufacturer‟s works if such facilities are available and to be witnessed by the
purchaser. The contractor, at no extra cost at the manufacturer‟s work shall carry out
routine and Acceptance tests in presence of the Purchaser‟s representatives.
Type Test Certificates for the tests conducted earlier shall be submitted with the bid
for evaluation. The requirements of additional type tests will be at the discretion of the
Purchaser
The Purchaser may witness routine and type tests. In order to facilitate this, the
contractor shall give the purchaser of 15days notice that the material is ready for inspection &
testing. The supplier shall extend all assistance to the representative of the Purchaser during his
inspection & testing of samples at his works. The materials shall be dispatched only after approval
of such Test Reports and issue of Despatch clearance by the Purchaser. However the Purchaser
reserves the right to retest the materials after delivery at any NABL Accredited Testing Laboratory
in case of any disputes regarding size & quality of supplied materials at a later date during
guarantee period. The cost of such retesting shall be borne by the supplier.
All costs in connection with the testing, including any necessary retesting shall be
borne by the Contractor, who shall provide the Purchaser with all the test shall have the right to
select the samples for test and shall also have the right to ensure that the testing apparatus is correct.
Measuring apparatus for routine tests shall be calibrated at the expense of the contractor at an
approved laboratory and shall be approved by the purchaser before testing.
The Contractor shall be responsible for the proper testing of the materials supplied by
sub- Contractor to the same extent as if the materials were completed or supplied by the contractor.
Any cost incurred by the Purchaser in connection with inspection or retesting as a
result of failure of the equipment under test or damaged during transport or off loading shall be to
the account of the Contractor.
The Contractor shall submit to the Purchaser three signed copies of the test
Certificates, giving the results of the tests as required. No materials shall be dispatched until the
Purchaser has received the test certificate and the contractor has been informed that they are
acceptable.
The test certificate must show the actual values obtained from the tests, in the units
used in this specification, and most merely confirm that the requirements have been met.
In the case of components for which specific type tests or routine tests are not given in
this specification, the Contractor shall include a list of the tests normally required for these
components. All materials used in the Contract shall withstand and shall be certified to have
satisfactorily passed such tests.
No inspection or lack of inspection or passing by the Purchaser‟s representative of equipment
or materials whether supplied by the Contractor or sub- Contractor, shall
relieve the contractor from his liability to complete the contract works in accordance with contract or
exonerate him from any of his guarantees.
20.0 GUARANTEE:
The contractor shall guarantee the following:
Quality and strength of materials used.
Satisfactory operation during the guarantee period of 24 months from the date of
commissioning or 30 months from the date of receipt of the cables at
NESCO,whichever is earlier.
21.0 22.0
Performance figures as supplied by the bidder in the technical data sheet.
PACKING AND SHIPPING:
The cable shall be wound on strong drums or reels capable of withstanding all normal
transportation and handing.
PERMANENT EMBOSSING:
All equipments and materials supplied/erected shall bear distinct mark of "
NESCOand Purchase Order No & Date "by w a y o f e m b o s s i n g /punching/casting
etc.including o t h e r i n f o r m a t i o n mentioned in GTP. This should be clearly visible to
naked eye.
GUARANTEED TECHNICAL PARTICULARS FOR LT XLPE AB CABLES
Sl No
1 2
Description
Ref. ISS / IEC followed
Phase Conductor material / Insulation type
3X35 + 1X16 +1X25mm2
Requirement
IS 14255/95, IS 398 Part IV
H2 / H4 E.C grade aluminium as per
IS 8130/84 / XLPE insulation ( IS 14255/95)
3X 50 + 1X16 +
1X35 mm2
Requirement
IS 14255/95, IS 398 Part IV
H2 / H4 E.C grade aluminium as per
IS 8130/84 / XLPE insulation ( IS 14255/95)
3X 35 + 1X25
mm2
Requirement
IS 14255/95, IS 398 Part IV
H2 / H4 E.C grade aluminium
as per IS 8130/84 / XLPE
insulation
1x35+1x25 mm2
Requirement
IS 14255/95, IS 398 Part IV
H2 / H4 E.C grade aluminium as per IS 8130/84
/ XLPE insulation ( IS 14255/95)
3
4
Material of Neutral
Catenary
Voltage Class
No. of Strands of Phase Conductor
Aluminum alloy as per IS 398 Pt - IV
0.65/1.1 KV
7
Aluminum alloy as per IS 398 Pt - IV
0.65/1.1 KV
7
( IS 14255/95) Aluminum alloy as per IS 398 Pt -
IV
0.65/1.1 KV
7
Aluminum alloy as per IS 398 Pt - IV
0.65/1.1 KV
7
No. of strands/ Average
5
6
/Minimum Strand Dia. In mm. (Finished Phase
conductor.)
Approximate Overall Dia. Of compacted phase conductor after removal
7/2.52
7 .0
7/3.05
9.15
7/2.52
7 .0
7/2.52
7 .0
of insulation.(in mm.)
No. Of Strands / Average
7
8
Strand Dia. In mm. (
Neutral Catenary.)
Minimum Overall Dia. Of compacted Bare
Neutral Caternary .(in mm.)
7 / 2.15
6. 0
7/2.54
7.62
7/2.15
6 .0
7/2.15
6 .0
No. Of Strands / Average strand dia. / Nomunal
cross sectional area of 9
10
11
conducting part In No / mm2.
( St. Light Conductor) Minimum average
thickness of insulation of phase Cond. (mm)
Minimum thickness of insulation of Phase Cond.
7 /1.75 / 16mm2
1. 2
0 .9 8
7 /1.75 / 16mm2
1. 5
1.25
N.A
1. 2
0 .9 8
N.A
1. 2
0 .9 8
At any point (mm )
Minimum thickness of
insulation at any point 12 in street light conductor
(mm)
Maximum DC resistance
0.98 0.98 N.A N.A
13
14
of Phoase conductor at 20 C ohmn/ KM
Maximum DC resistance of street light conductor
Ω / Km
0.868
1.91
0.64
1.91
0.868
N.A
0.868 N.A
15 16 17
Maximum DC resistance of neutral cond. Ω / Km
Ultimate tensile strength of neutral conductor
(KN)
Maximum temperature (Continuous)
1 .3 8
7
90°C for phase and 75 °C for neutral
0.986
14
90°C for phase and
75 °C for neutral
1 .3 8
7
90°C for phase
and 75 °C for neutral
1 .3 8
7
90°C for phase and 75 °C for neutral
Distinct Non-
erasable ISI Mark, IS 14255-95,
Manufacturer‟s B.I.S License No.,
Distinct Non-
erasable ISI Mark, IS 14255-95,
Manufacturer‟s B.I.S License No.,
Distinct Non- erasable ISI
Mark, IS 14255- 95,
Manufacturer‟s B.I.S License
No., Name of the
Distinct Non- erasable
ISI Mark, IS 14255-95,
Manufacturer‟s B.I.S License No., Name of
the Purchaser, Name
18 Embossing on insulation
at each one meter interval
Name of the Purchaser, Name
of the manufacturer, Size
of cable, voltage
Grade along with
sequential
marking of length.
Name of the Purchaser, Name
of the manufacturer, Size
of cable, voltage
Grade along with
sequential
marking of length..
Purchaser, Name of the
manufacturer, Size of cable,
voltage Grade along with
sequential
of the manufacturer, Size of cable, voltage
Grade along with sequential
marking of length.
marking of length.
19
20
21
Cable drum length
Volume Resistivity of insulation at 27°C
Volume Resistivity of insulation at 70°C
500 m
1X1013Ώ - cm min.
1X1011Ώ - cm min.
500 m
1X1013Ώ - cm min.
1X1011Ώ - cm min.
500m
1X1013Ώ - cm min.
1X1011Ώ - cm min.
500 m
1X1013Ώ - cm min.
1X1011Ώ - cm min.
Sl. Name of the Particulars
31/2 C 185 mm2 LT unarmoured
AB cable
Bidd
er's
Offer
31/2 95 mm2 LT unarmoured
AB cable
Bidder
's
Offer
Aluminium
Aluminium
Type of
Conductor
1 Conductor ,XLPE
cable
,XLPE
Insulated
Insulated
2 Conductor
Details
a No of Cores 3 &1/2 3 &1/2
b Normal Cross-Sectional Area 31/2 185 sqmm 31/2 95 sq mm
c Material and Grade
Aluminium
compacted,Strande
d as per IS: 8130
with latest
amendment
Aluminium
compacted,Strande
d as per IS: 8130
with latest
amendment
d Shape of
Conductor Circular Circular
e As per REC
Spec. As per REC Spec.
No. of Strands and Diameter as per IS 8130
with
8130 with
f
of each Strand
latest amendment
latest
amendment
3 Rated Voltage 1.1 kV 1.1 kV
Maximum
900 C
900 C
4 Conductor temperature for
Maximum conductor
5 temperature during 2500C 250
0C
short circuit
6 Insulation
a Material XLPE XLPE
b Nominal Thickness
As per REC Spec.
As per REC
Spec
(Phase/ Neutral)
7 Vulcanization Process
a Curing Method Dry Curing Dry Curing
b Cooling Method Inert Gas Inert Gas
8 Inner Sheath
a Material
PVC
PVC
b Thick ness of inner sheath
(mm) As per REC As per REC
Diameter of Cable after
inner Manufacture
to Manufactur
e
c sheath application
Specify
to Specify
Outer Sheath
PVC PVC
9
PVC PVC
a Type
FR ST 2 as per IS FR ST 2 as
5831 per IS 5831
b Colour
Black
Black
c Thickness 2.2
2.2
Manufactur
10 Nominal OVerall Diameter of
Manufacture to Specify
Cable Specify
11 Nominal Overall Weight of
Manufacture to Manufacture
Cable per Metre Specify
to Specify
Minimum Bending Radius al
As per Is 1255 /
As per Is
1983
12 1255 / 1983 during installation with latest
amendment
Short Circuit Current
13 Rating of As per
REC As per
REC
f o r 1 S e c
14 Soil Parameter
a
Soil Temperature
C
C
Ambient
b Temperature C C
Soil Thermal
c Resistivity
C Cm/W C Cm/W
Normal current
rating
15 in ampere
Groun
a d
As per REC
As per REC
b Ducts As per REC As per REC
c Air As per REC As per REC
16 Maximum DC Resistance at
As per REC
As per REC
20°C ohm/km
17 Maximum AC Resistance at
As per REC
As per REC
90°C ohm/km
Reactance of As per REC
As per REC
18 Cable in in ohm/km
As per REC
capacitance of cable in
19 micro farad/km 0.29 0.29
Derating factor of Cable
20 installed As per IS
As per IS
TECHNICAL SPECIFICATION OF LT TWO CORE XLPE, UNARMOURED 16 SQMM CABLE IN SUB STATION
Sl.
Name of the Particulars 2x16SQMM Bidder's Offer No
1 Type of cable Aluminium Conductor, XLPE
Insulated
2 Conductor Details
a No of Cores 2
b Normal Cross -
2x16SQMM
Sectional Area
c Material and Grade
Aluminium compacted, Stranded as per IS: 8130
with latest amendment
d Shape of Conductor
Circular
e Diameter of Conductor 2X4.5 mm
No. of Strands and
f Diameter of each as per IS 8130 with latest
amendment Strand
3 Rated Voltage 1.1 kV
Maximum Conductor 90
0 C
4 temperature for continuous operation
Maximum conductor
5 temperature during 2500C
short circuit
6 Insulation
a Material XLPE
b Nominal Thickness 0.7 mm
7 Vulcanization Process
a Curing Method Dry Curing
b Cooling Method Inert Gas
8 Inner Sheath
a Material
PVC
b Thick ness of inner
0.3
sheath (mm)
Diameter of Cable
c after inner sheath
Manufacture to Specify
application
Outer Sheath
PVC
9
a Type
FR ST 2 as per IS 5831
b Colour
Black
c Thickness 1.8
10 Nominal OVerall
Manufacture to Specify
Diameter of Cable
11 Nominal Overall Weight
Manufacture to Specify
of Cable per Metre
Minimum Bending As per Is 1255 / 1983
12 Radius allowable
with latest amendment
during installation
Short Circuit Current
13 Rating for 1 Sec 1.5 kA
14 Soil Parameter
a Soil Temperature
C
b Ambient Temperature
C
Soil Thermal
c Resistivity C Cm/W
15 Normal current rating
in ampere
a Ground
78A
b Ducts 61A
c Air 70A
Maximum DC
16 Resistance at 20°C 1.91
ohm/km
Maximum AC
17 Resistance at 90°C 2.44
ohm/km
18 Reactance of
0.080
Cable in in ohm/km
19 capacitance of cable
0.18
in micro farad/km
20 De rating factor of
As per IS
Cable installed
Sl. Name of the Particulars
31/2 C 300mm2 LT unarmoured
AB cable
Bidd
er's
Offer
31/2 50 mm2 LT unarmoured
AB cable
Bidder
's
Offer
Aluminium
Aluminium
Type of
Conductor
1 Conductor ,XLPE
cable
,XLPE
Insulated
Insulated
2 Conductor
Details
a No of Cores 3 &1/2 3 &1/2
b Normal Cross-Sectional Area 31/2 300 sqmm 31/2 50 sq mm
c Material and Grade
Aluminium
compacted,Strande
d as per IS: 8130
with latest
amendment
Aluminium
compacted,Strande
d as per IS: 8130
with latest
amendment
d Shape of
Conductor Circular Circular
e As per REC
Spec. As per REC Spec.
No. of Strands and Diameter as per IS 8130
with
8130 with
f
of each Strand
latest amendment
latest
amendment
3 Rated Voltage 1.1 kV 1.1 kV
Maximum
900 C
900 C
4 Conductor temperature for
Maximum conductor
5 temperature during 2500C 250
0C
short circuit
6 Insulation
a Material XLPE XLPE
b Nominal Thickness
As per REC Spec.
As per REC
Spec
(Phase/ Neutral)
7 Vulcanization Process
a Curing Method Dry Curing Dry Curing
b Cooling Method Inert Gas Inert Gas
8 Inner Sheath
a Material
PVC
PVC
b Thick ness of inner sheath
(mm) As per REC As per REC
Diameter of Cable after
inner Manufacture
to Manufactur
e
c sheath application
Specify
to Specify
Outer Sheath
PVC PVC
9
PVC PVC
a Type
FR ST 2 as per IS FR ST 2 as
5831 per IS 5831
b Colour
Black
Black
c Thickness 2.2
2.2
Manufactur
10 Nominal OVerall Diameter of
Manufacture to Specify
Cable Specify
11 Nominal Overall Weight of
Manufacture to Manufacture
Cable per Metre Specify
to Specify
Minimum Bending Radius al
As per Is 1255 /
As per Is
1983
12 1255 / 1983 during installation with latest
amendment
Short Circuit Current
13 Rating of As per
REC As per
REC
f o r 1 S e c
14 Soil Parameter
a
Soil Temperature
C
C
Ambient
b Temperature C C
Soil Thermal
c Resistivity
C Cm/W C Cm/W
Normal current
rating
15 in ampere
Groun
a d
As per REC
As per REC
b Ducts As per REC As per REC
c Air As per REC As per REC
16 Maximum DC Resistance at
As per REC
As per REC
20°C ohm/km
17 Maximum AC Resistance at
As per REC
As per REC
90°C ohm/km
Reactance of As per REC
As per REC
18 Cable in in ohm/km
As per REC
capacitance of cable in
19 micro farad/km 0.29 0.29
Derating factor of Cable
20 installed As per IS
As per IS
11 / .25 KV, 16 KVA ( STAR RATED) ALUMINIUM WOUND DISTRIBUTION TRANSFORMER
1.0 SCOPE:-
1.1 This specification covers design, manufacturing, testing and delivery of 16 KVA, 11/0.25 single
phase, oil immersed, Oil Natural (ON) distribution transformer (Sealed type) confirming to
energy efficiency level-2 of IS 1180(Part-1): 2014 suitable for 11 KV and 50 Hz distribution
system.
1.2 The equipment offered shall be complete with all parts necessary for their effective and trouble-free
operation. Such parts will be deemed to be within the scope of the supply irrespective of whether
they are specifically indicated in the commercial order or not.
1.3 It is not the intent to specify herein complete details of design and construction. The equipment
offered shall conform to the relevant standards and be of high quality, sturdy, robust and of good
design and workmanship complete in all respects and capable to perform continuous and
satisfactory operations in the actual service conditions at site and shall have sufficiently long life in
service as per statutory requirements.
1.4 The design and constructional aspects of materials shall not withstanding any anomalies,
discrepancies, omissions, in-completeness, etc. in these specifications and will be subject to good
engineering practice in conformity with the required quality of the product, and to such tolerances,
allowances and requirements for clearances etc. as are necessary by virtue of various stipulations in
that respect in the relevant Indian Standards, IEC standards, I.E. Rules, I.E. Act and other statutory
provisions.
1.5 The Bidder / supplier shall bind himself to abide by these considerations to the entire satisfaction of
the purchaser and will be required to adjust such details at no extra cost to the purchaser over and
above the tendered rates and prices.
1.6 Tolerances:
The tolerance of guaranteed performance figures shall be as specified in the (Part-I) table 7 of latest
issue of IS 2026 or relevant International Standard except wherever specified otherwise in this
specification.
2.0 System Particulars:-
34
The transformers shall be suitable for outdoor installation with following system particulars and they should be suitable for service under fluctuations in supply voltage as permissible under
Indian Electricity Rules.
Nominal System Voltage : 11Kv
Corresponding Highest System Voltage : 12Kv
Neutral earthling : Solidly earthed
Frequency : 50Hz with + 5% tolerance
Number of phase : 1
3.0 SERVICE CONDITIONS:
The service conditions shall be as follows:
maximum altitude above sea level 1,000m
maximum ambient air temperature 50° C
maximum daily average ambient air temperature 40° C
minimum ambient air temperature -5° C
maximum temperature attainable by an object exposed to the sun 60 ° C
maximum yearly weighted average ambient temperature 32° C
maximum relative humidity 100%
average number of thunderstorm days per annum (isokeraunic level) 70
average number of rainy days per annum 120
average annual rainfall 1500 mm
maximum wind pressure 260Kg / m2
Environmentally, the region where the equipment will be installed includes coastal areas, subject to high relative humidity, which can give rise to condensation. Onshore winds will frequently be salt laden. On occasions, the combination of salt and condensation may create pollution conditions for outdoor insulators. Therefore, outdoor material and equipment shall be designed and protected for use in exposed, heavily polluted, salty, corrosive, tropical and humid coastal atmosphere.
4.0 APPLICABLE STANDARDS:-
The design, manufacture and performance of the equipment shall comply with all currently
applicable statutes, regulations and safety codes.
The Distribution Transformers (Sealed type) shall conform to energy efficiency level-1 (3-Star
rated) of IS 1180(Part-I) 2014.
35
Unless otherwise specified, the equipment offered shall conform to latest applicable Indian, IEC,
British or U.S.A. Standards and in particular, to the following :-
a. IS 2026(Part I,II,IV)/1997,(Part-III)/1981,(Part- Power & Distribution Transformer
V)/1994
b. IS : 1180(Part-I) 2014 Single phase distribution transformers
16 KVA, 11/0.25KV Sealed type.
c. IS : 335 / 1993 New insulating oil – Specification (fourth
revision)
d. IS:2099/ 1986, IS:7421 – 1988, Bushing
IS:3347 (Part-I/Sec-2)-1979,
IS:3347 (part-I/Sec-I) – 1982
Amended up to date
e. IS 5 Colours for ready mixed paints and
enamels.
f. IS 13730 (part – 27) 1996 Specification for particular types of
winding wires.
g. IS : 3073 / 1974, IS : 3070 (part – II) Specifications for Lighting Arrestors
h. CBIP Publication No. 295:2006 Manual on transformers
In case of conflict arising out due to variations between the applicable standard and the standards
specified herein, the provisions of this specification should prevail. 5.0 Specific Technical requirement:
a) Standard KVA Ratings: - The standard ratings for transformer shall be 16 KVA.
b) Nominal voltage ratings: Primary voltage: 11KV, Secondary voltage: 0.250 KV.
c) Winding connections:-
i.
H.V.
Winding : Series
ii. L.V. Winding : Series / Parallel
d) Temperature Rise:
i. The temperature rise for top oil over an ambient temperature of 500 C should be 35
0
C maximum. i.e. Max. Temp. Of top oil shall not exceed 850 C.
ii. Temperature rise for winding over an ambient temperature of 500 C should be 40
0 C
maximum. i.e. Max. Temp. of winding shall not exceed 900 C.
e) No load voltage ratio: - The no load voltage ratio shall be 11000/250 Volts
f) Tapping: - No tap switch to be provided.
6.0 Design & construction
6.1 Core
i) The core shall be stacked type
a) For Stack core :- The core shall be of high prime grade cold rolled grain oriented (C.R.G.O)
annealed steel lamination having low loss and good grain properties, coated with hot oil
proof insulation, bolted together to the frames firmly to prevent vibration or noise. All core
clamping bolts shall be effectively insulated. The complete design of core must ensure
permanency of the core losses with continuous working or the transformers.
b) The construction of Top/Bottom yoke shall be one. No cut core shall be allowed by any
case.
ii) The grade of core laminations shall be CRGO, M3 Grade (0.23mm) or better. The grade
of core laminations shall be required to submit the manufacturer‟s test report showing the
watt Loss per kg and the thickness of the core lamination, to ascertain the quality of Core
materials. The purchaser reserves the right to get sample of the core material tested at any
Government recognized laboratory.
iii) The transformer core shall not be saturated for any value of V/f ratio to the extent of
112.5% of the rated value of V/f ratio (i.e. 11000/50 or 22000/50) (due to combined effect
of voltage and frequency) up to 12.5% without injurious heating at full load conditions and
will not get saturated. The bidder shall furnish necessary design data in support of this
situation.
iv) Core base and bottom yoke shall be supported with 40 x 5 mm MS plate of adequate size
properly bolted together.
v) Flux Density:-
Flux density should not be more than 1.50 Tesla at the rated voltage and frequency. The
value of the flux density allowed in the design shall be clearly stated in the offer along with
graph.
vi) The No load current at rated voltage shall not exceed the percentage given in Table below. 37
Sr. KVA
No. Rating At Rated Voltage At 112.5% Rated Voltage
1 16 2.0% of the full load current in LT winding 4.0% of the full load current
vii) Number of steps of core shall be of minimum 5 for 16 KVA transformers.
Note: In case if it is found at any stage that the core used is defective/second used/scrap
core or No load loss found to be more than stipulated limits, the supplier is liable for
imposing penalty and even blacklisting the firm at the discretion of Purchaser.
6.2 Winding:-
a) Materials: Double paper covered Aluminum conductor shall be used for HV and LV winding. b) Current Density: Current density for HV and LV winding or any part should not be more than
1.4 A/ sq.mm. c) L.V. Neutral formation shall be at top.
d) Vertical ducts & sufficient spacers should be provided between HV & LV windings. e) The current density of delta lead shall not exceed 0.8 A/mm
2
f) The no of LV coil and HV coil in one limb shall be 1 & 4 for 16 KVA transformers. 6.3 Losses:
The Losses shall not exceed the values given below
KVA Max. Total losses at Max. Total losses at 100%
50% load (W) load (W)
16 95 265
No tolerance for losses of 11/0.25 kV. Distribution transformers as per IS: 1180 (Part 1)2014. In
case the actual loss values exceed the above guaranteed values, the transformers shall be rejected at
the risk, cost and responsibility of the supplier.
The values guaranteed in G.T.P. for flux density, no load current at rated voltage, no load current at
112.5% of rated voltage and no load loss at rated voltage shall be individually met.
6.4 Insulation material & clearances:
a) Materials – Makes of Electrical grade insulating craft paper, press Board, Parma wood/ Haldi wood insulation shall be declared in GTP by the bidder. The test reports for all properties as per relevant I.S. amended up to date shall be submitted during inspection.
38
b) The electrical clearance between the winding and body of the tank (between inside surface of the tank and outside edge of the windings) should not be less than 25 mm for 11 KV class.
Minimum external clearances of bushing terminals
HV Ph to PH 255mm
Ph to E 140mm
LV Ph –to-Ph 75mm.
Ph to E 40mm
c) The clearance between HV coil & Top/Bottom yoke shall be 21 mm (min).
d) Inter coil insulation shall not be less than 6 mm.
e) The insulation between core & LV shall be 2.5 mm (min).
f) The insulation between HV coil & LV coil shall be 10 mm (min).
g) Minimum 6 nos. of wedges to be provided.
6.6 Impedance Value –
The percentage impedance at 750 C. shall be 4% for 16 KVA transformers with positive tolerance
of 10%. No negative tolerance on % impedance is allowed.
6.7 Tank 6.7.1 The transformer tank shall be made up of prime quality, High grade, low carbon steel plate &
suitable for welding. The transformer tank shall be of robust construction. All joints of tank and
fittings should be oil tight and no bulging shall occur during service. The tank design shall be such
that the core and windings can be lifted freely. The tank plates shall be of such strength that the
complete transformer when filled with oil may be lifted bodily means of the lifting lugs provided.
Tank inside shall be painted by hot oil resistant varnish or paint. Top cover plate shall be slightly
sloping approximately 5 to 10 deg.Towards HV bushing and edges of cover plate should be bent
downwards so as to avoid entry of water through the cover plate gasket. The width of bend plate
shall be 25mm min. the top cover shall have no cut at point of lifting lug. The construction of
Single phase sealed type transformer tank shall be as per Clause No.15 of IS 1180(Part-1)2014
and should conform the pressure and vacuum requirement as per said IS.
Wall thickness : 3.15 mm. (min)
39
Top and bottom plate thickness : 5 mm. (min.)
6.7.2 All welding operations to be carried out by MIG process. 6.7.3 Lifting lugs: 2 no‟s for 16 KVA of MS plate of 10 mm thickness suitably shall be reinforced.
6.7.4 Vertical clearance: - The height of the tank shall be such that minimum vertical clearance up to the top cover plate is achieved from the top of yoke for the sealed type transformers.
7.0 PUNCHINGS: Non-erasable Punching and embossing of Volume of oil in litres, name of the
Purchaser- SOUTHCO, Orissa, Name of the Supplier – M/s -------------------------------, Year of
Manufacture, Guarantee Period and Sl. No. of each transformer is to be made on top core channel,
top cover, side walls and name plates of transformers.
7.0.1 3 STAR LEVEL: In addition to above, the supplied Distribution Transformers must contain 3
Star Level with style and information provided by the Bureau of Energy Efficiency (B.E.E), Ministry
of Power, Government of India. 8.0 Painting
8.1 All paints shall be applied in accordance with the paint manufacturer‟s recommendations.
Particular attention shall be paid to the following: 8.2 a) Proper storage to avoid exposure as well as extremes of temperature.
b) Surface preparation prior to painting. c) Mixing and thinning d) Application of paints and the recommended limit on time intervals between coats. e) Shelf life for storage.
8.3 All paints, when applied in normal full coat, shall be free from runs, sags, wrinkles, patchiness,
brush marks or other defects.
8.3.1 All primers shall be well marked into the surface, particularly in areas where painting is evident, and the first priming coat shall be applied as soon as possible after cleaning. The paint shall be applied by airless spray according to the manufacturer‟s recommendations. However, wherever airless spray is not possible, conventional spray be used with prior approval of purchaser.
8.3.2 The supplier shall, prior to painting protect nameplates, lettering gauges, sight glasses, light fittings
and similar such items.
8.4 Cleaning and Surface Preparation
8.4.1 After all machining, forming and welding has been completed, all steel work surfaces shall be
thoroughly cleaned of rust, scale, welding slag or spatter and other contamination prior to any painting.
40
8.4.2 Steel surfaces shall be prepared by Sand/Shot blast cleaning or Chemical cleaning by Seven tank process including Phosphating to the appropriate quality.
8.4.3 The pressure and Volume of the compressed air supply for the blast cleaning shall meet the work
requirements and shall be sufficiently free from all water contamination prior to any painting.
8.4.4 Chipping, scraping and steel wire brushing using manual or power driven tools cannot remove
firmly adherent mill-scale and shall only be used where blast cleaning is impractical.
8.5 Protective Coating
8.5.1 As soon as all items have been cleaned and within four hours of the subsequent drying, they shall
be given suitable anticorrosion protection.
8.6 Paint Material
Followings are the type of paints that may be suitably used for the items to be painted at shop and supply of matching paint to site:
i) Heat resistant paint (Hot oil proof) for inside surface.
ii) For external surfaces one coat of Thermo Setting Paint or 2 coats of Zinc chromate followed by 2 coats of P.U (Poly-urethene) paint. The color of the finishing coats shall be dark admiral gray.
8.7 Painting Procedure 8.7.1 All painting shall be carried out in conformity with both specifications and with the paint
manufacture‟s recommendations. All paints in any one particular system. Whether shop or site applied, shall originate from one paint manufacturer.
8.7.2 Particular attention shall be paid to the manufacturer‟s instructions on storage, mixing, thinning and pot life. The paint shall only be applied in the manner detailed by the manufacturer e.g. brush, roller, conventional or airless spray and shall be applied under the manufacturer‟s recommended conditions. Minimum and maximum time intervals between coats shall be closely followed.
8.7.3 All prepared steel surfaces should be primed before visible re-rusting occurs or within 4 hours whichever is sooner. Chemical treated steel surfaces shall be primed as soon as the surface is dry and while the surface is warm.
8.7.4 Where the quality of film is impaired by excess film thickness, (wrinkling, mud cracking or general softness) the supplier shall remove the unsatisfactory paint coatings and apply another. As a general rule, dry film thickness should not exceed the specified minimum dry film thickness by more than 25%. In all instances, where two or more coats of the same paints are specifies, such coatings may or may not be of contrasting colors.
8.7.5 Paint applied to items that are not be painted, shall be removed at supplier‟s expense, leaving the
surface clean, un-stained and undamaged.
41
8.8 Damages to Paints Work
Any damage occurring to any part of the painting scheme shall be made good to the same standard of corrosion protection and appearance as that originally employed. Any damaged paint work shall be made as follows:
a) The damaged area, together with an area extending 25mm around its boundary, shall be cleaned down to bare metal.
b) A priming coat shall immediately applied, followed by a full paint finish equal to that originally applied and extending 50mm around the perimeter of the originally damaged.
The repainted surface shall present a smooth surface. This shall be obtained by carefully chamfering the paint edges before & after priming.
8.9 Dry Film Thickness
To the maximum extent practicable, the coats shall be applied as a continuous film of uniform thickness and free of pores. Over-spray, skips, runs, sags and drips should be avoided. The different coats may or may not be same color.
Each coat of paint shall be allowed to harden before the next is applied as per manufacture‟s recommendations. Particular attention must be paid to full film thickness at edges.
The requirement for the dry film thickness(DFT) of paint and the material to be used shall be as given below:
Sl. Paint Type Area to be No of Total Dry film thickness(Min)
No painted Coats
1. Liquid paint
a) Zinc Chromate (Primer) Out side 01 30 micron
b) P.U. Paint (Finish Coat) Out side 02 45 each
c) Hot Oil paint
inside 01 35/10 micron
The colour of the finishing coat shall be Sky Blue/Dark admiral Gray/Deep Green or any other
colour as decided by the purchaser.
9.0 Heat Dissipation :
a) Heat dissipation by tank walls excluding top and bottom should be 500W / sq, m.
10.0 Mounting Arrangement :
a) The transformers shall be provided with two mounting lugs suitable for fixing the
transformer to a single pole by means of 2 bolts of 20 mm dia. The transformer shall also
42
be provided with base plates of 50x8 mm thickness for fixing the transformer on a platform.
10.1 Terminals :
Brass terminal stud of suitable size to carry 250 AMP for HT with necessary nuts, check-nuts and
plain thick tinned washer. Each HT bushing shall be provided with a bi-metallic terminal connector
to receive 25-100 sq mm AAAC. Brass terminal stud of suitable size to carry 250 A for LT with
necessary nuts, check-nuts and plain thick tinned washer.
10.2 Bushings & Connections :
10.2.1 For 11 KV, class 12KV bushing, shall be used and for 250 volts, 1.0 KV bushing shall be used.
Bushings of the same voltage class shall be interchangeable. 10.2.2 The minimum creep age distance for both HV & LV Bushings shall not be less than 25mm per
KV. 10.3 Internal Connections: 10.3.1 H.V. Winding:
In case of HV winding all jumpers from winding to bushing shall have cross section larger than winding conductor. Inter coil connection shall be by crimping and brazing.Lead from series joint shall be connected to
bushing rod by brazing only. The current density in series lead shall be less than 1.4 A/mm2
10.3.2 L.V. Winding:
i.) L.T. Series/parallel point shall be formed of Aluminum/Copper flat of sufficient length &
size. Lead from winding shall be connected to the flat by crimping and brazing. ii) For Aluminum windings, L&T Alkapee aluminum brazing rods with suitable flux shall be
used. 10.4 Terminal Marking Plates and Rating Plates :
Each transformer shall be provided with a rating plate of weatherproof material showing the
following items indelibly marked which should conform to the rating plate and terminal marking
plate for single phase transformers without taps as per IS:1180(Part-1)2014. type of transformer standard to which it is manufactured IS-1180(Part-1) 2014. manufacturer‟s name transformer serial number
43
year of manufacture rated frequency in Hz (50) rated voltages in KV (11/0.433) number of phases (3) rated power in KVA type of cooling (ONAN) rated currents in A vector group symbol (Dyn11) 1.2/50µs wave impulse voltage withstand level in KVp power frequency withstand voltage in KV
impedance voltage at rated current and frequency in percentage at 75 0 C at normal tap
Measured load loss in KW at rated current and at 75 0 C at normal tap
Measured no-load loss in KW at rated voltage and rated frequency Maximum total losses(in Watt) at 100% load Maximum total losses(in Watt) at 50% load
continuous ambient temperature at which ratings apply in 0C
top oil and winding temperature rise at rated load in 0C
winding connection diagram Total weight in kg with complete oil filled. total weight of the transformer without oil Volume of oil in litres. weight of core and windings in kg; and name of the purchaser SOUTHCO, DESI, PHULBANI, GoO. 10.5 Fittings (As per clause no.20 of IS 1180(Part-1)2014) :
The fittings on the transformers shall be as under:
1 Rating and diagram plate 1no.
2. Earthing terminals with lugs 2 no.
3. Lifting lugs 2 nos
4. Oil filling hole with cap (on cover) 1 no.
5. Thermometer pocket with cap 1 no.
6. mounting arrangement 2 no.
7. Arching Horn for HT bushing As required
8. Oil level gauge indicating 3 positions 1 no.
of oil marked as below : (on side wall)
44
Minimum (-) 50 C.
Normal 300 C
Maximum 980 C
9. HT & LT bushing & connectors
2 HT & 2 LT bushings. Each bushing
(HV
& LV) should be provided with 3 nos. of
brass nuts and 2 plain brass washers &
with bimetallic connectors of suitable
size.
10. Any other required fittings as per
above said IS for Single phase sealed
type transformer.
10.6 Transformer Oil
The transformers shall be supplied complete with first filling of transformer oil upto maximum
permissible level. The quantity of oil required for the first filling of the transformer and its full
specification shall be stated in the bid. The complete first filling shall be of new oil free from
inhibitors and additives up to maximum permissible level for the supplied Transformer. The
bidder shall quote the price of transformer including the cost of Transformer Oil required for
initial filling.
The insulating oil for the transformer shall be of EHV grade, generally conforming to IEC: 296/
BS: 148/ REC: 39/ 1993 or latest version of IS: 335/ 1983 whichever is more stringent. No
inhibitors shall be used in the oil. The dielectric strength of the oil shall not be less than 60 KV
at 2.5 mm. gap when tested in accordance with IS: 6792/ 1972. If an anti-oxidant inhibitor is
recommended, its use shall be subject to the purchaser‟s approval.
The design and materials used in the construction of the transformer shall be such as to reduce
the risk of the development of acidity in the oil.
The contractor shall warrant that oil furnished is in accordance with the following specifications.
Sl.No Characteristic Requirement Method of Test
01 Appearance The oil shall be clear & A representative sample of oil shall
transparent & free from be examined in a 100 mm thick
suspended matter or layer at ambient temp.
sediment
02 Density at 200C 0.89 g/cm
3 Max. IS:1448
03 Kinematic Viscosity at 27 CST IS:1448
45
27 deg. C Max
04 Interfacial tension at 0.03 N/m IS:6104
27deg.C Min.
05
Flash
Point 136 0C IS:1448
06 Pour Point Max. -6 0C IS:1448
07 Naturalization Value 0.03 mg KOH/gm IS:335
(Total Acidity) Max.
08 Electric strength 72.5 KV IS:6792
Breakdown (voltage)
Min.
09 Dielectric dissipation 0.03 Max IS:6262
factor tan delta at 900 C
10 Min specific resistance 35X1012
ohm cm (min.) IS:6103 (resistively) at 90 deg.C
11 Oxidation stability
12 Neutralization value 0.40mg KOH/g
after oxidation
13 Total sludge after 0.10% by weight max.
oxidation
14 Presence of oxidation The oil shall not contain anti- IS:335
Inhibitor oxidant Additives.
15 Water content Max: Less than 25ppm IS:2362
11.0 Test and Inspection:-
11.1 Testing facility
The bidder should have adequate testing facility for all routine and acceptance tests and also
arrangement for measurement of losses, resistance, etc. details of which will be enumerated in the
tender.
The inspector of the purchaser will witness routine, Acceptance & type tests. In order to facilitate
this, the manufacturer shall give a 15 days notice that the material is ready for inspection & testing.
The material shall be dispatched only after approval of such test reports and issue of Dispatch
clearances by the purchaser. However the purchaser reserves the right to retest the
transformers after delivery at any NABL Accredited Testing Laboratory in case of any
disputes regarding guaranteed specifications of supplied transformers at a later date during
guarantee period. The cost of such retesting shall be borne by the supplier.
11.2 Routine & Acceptance Tests:- 46
11.2.1 All transformers shall be subjected to the following tests at the manufacturer‟s works. The tests are
to be carried out in accordance with the details specified in IS 2026 or as agreed upon between the
purchaser and the manufacturer.
A) Measurement of winding resistance.
B) Ratio, polarity and phase relationship.
C) Impedance voltage. D) Load losses at 75⁰ C. E) No-load losses and No-load current. F) Insulation resistance. G) Induced over voltage withstand.
H) Separate source voltages withstand. I) Pressure and Oil leakage test. J)Maximum total losses at 50% load.
K) Maximum total losses at 100% load. 11.2.2 All the routine tests shall be conducted in the suppliers‟ laboratory at their cost.
11.2.3 Heat run test shall be arranged free of cost on the unit selected from the 1st
lot by Authorized Representative.
11.2.4 The calculations to confirm the thermal ability as per Clause no. 9.1 of latest IS: 2026 Part-I or
equivalent International Standard shall be submitted to our representative. 11.3 Type Tests :
The bidder should submit the report of following tests carried out in a NABL accredited laboratory:-
a) Temperature Rise Test
b) Short Circuit Test containing the measured no load loss and load loss. c) Impulse Test d) Pressure test
The balance type tests as stated below should be carried at the manufacturer‟s works invariably in
the presence of representative of the purchaser at the time of inspection from the first lot.
a. Temperature Rise Test.
b. Air pressure test as per clause no.21.5 of IS: 1180 (Part-I)/2014. c. Unbalanced current test.
47
In respect of the successful bidder, the purchaser reserves the right to demand repetition of some or
all the above tests in presence of the purchaser‟s representative. In case the unit fails in the type
tests or routine tests, the complete lot offered shall be rejected. 11.4 Submission Routine Test Certificate
The successful bidder shall submit the routine test certificate along with documentary evidence for
having paid the Excise Duty for the following raw materials viz. Oil, Aluminum, copper for
conductors, insulating materials, core materials, bushings at the time of routine testing of the fully
assembled transformer. 11.5 Stage Inspection
11.5.1 Supplier shall give 15 days‟ advance intimation to the purchaser to organize stage inspection in which assembly of core, windings and other core materials etc. would be inspected. In respect of raw materials such as core stamping, winding conductor, oil etc. successful bidder shall use these materials manufactured/supplied by the standard manufacturers and furnish the manufacturer‟s test certificates, as well as, proof of purchase from those manufacturers documentary evidence for having paid the excise duty for the information of the department. Purchaser will depute his representative at the time of stage inspection.
11.5.2 All the transformers from the offered lot will be tested for acceptance tests at factory, in the
presence of purchaser‟s representative before dispatch.
11.5.3 The inspection may be carried out by the purchaser at any stage of manufacture. The successful
bidder shall grant free access to the purchaser‟s representatives at a reasonable time when the work is in progress. Inspection and acceptance of any equipment under this specification by the purchaser shall not relieve the supplier of his obligation of furnishing equipment in accordance with the specifications and shall not prevent subsequent rejection if the equipment is found to be defective.
11.5.4 The purchaser may at its option, open a transformer supplied to the Stores, in presence of supplier
at site or at Stores. If any of the technical particulars are seen to be in variance than the guaranteed technical particulars, the whole lot of transformer will be rejected without any liability on purchaser.
11.5.5 Testing of all Distribution Transformers for no load and full load losses.
After inspection of new transformers at factory for acceptance of the lot, all distribution
transformers from the lot will be tested for no load and full load losses at all stores. Bidder has the
liberty to be present at the time of testing.
11.5.6 Inspection & testing of Transformer Oil :
48
The bidder shall make arrangements for testing of transformer oil to be used in the transformers testing will be done in presence of purchaser‟s representative.
To ascertain quality of transformer oil, original manufacturer‟s test report should be furnished to (Testing) at the time of factory inspection for acceptance of the lot.
11.6 Rejection:-
Apart from rejection due to failure of the transformer to meet the specified test requirements the
transformer shall be liable for rejection on any one of the following reasons.
(i). Losses exceed the specified values mentioned in specification.
(ii). Impedance voltage value exceeds the guaranteed value plus tolerances as per
specification.
(iii). Type test are not carried out as per the specification.
(iv). Drawings are not submitted as per the specification.
(v). GTP not submitted as per the specification.
(vi). Heat dissipation calculation sheet are not submitted as per the specification. 11.7 Quality Assurance
a) The bidder shall invariably furnish Test certificates and information as following along with the
offer failing to which the offer will be rejected.
(i). Aluminum and copper conductor.
(ii). Transformer oil.
(iii). Core
(iv). Insulating paper
(v). Porcelain Bushings
(vi). Steel Plate used for Tank.
(vii). List of testing & measuring equipments indicating the make, type, year of manufacture,
Last date of Calibration, Name of the agency carried out the calibration etc. Purchaser
reserves the right to visit the works of manufacturer to ensure the available testing facility
prior to placement of order.
b) Names of the supplier for the raw materials, list of standard accordingly to which the raw materials
are tested, list of test normally carried out on raw materials in presence of bidder‟s representatives,
copies of type test certificates.
c) Information and copies of test certificate as in (i) above respect of bought out accessories including
terminal connectors.
49
d) List of manufacturing facilities available. In this list the bidder shall specifically mention whether
lapping machine, vacuum drying plant, air conditioned dust free room with positive air pressure for
provision of provision of insulation and winding etc. are available with him.
e) Level of automation achieved and list of areas where manual processing still exists.
f) List of areas in manufacturing process where stage inspection are normally carried out for quality
control and details of such tests and inspections.
g) Special features provided in the equipments to make it maintenance free.
h) List of testing equipment available with the bidder for final testing of transformers and test plant
limitation, if any, vis-à-vis the type, special acceptance and routine tests specified in the relevant
standards and the present specification.
11.8 Drawings:- A set of following drawings with all dimensions shall be submitted by the Bidder along with the offer :
a) General Dimensional drawing.
b) Core Assembly drawing. c) Internal Construction Drawing. d) Rating & Diagram Plate Drawing. e) HV/LV Bushings indicating measurement of creep age distances. f) Operation and Maintenance Manual.
The drawings shall be of A-3 (420x297mm) size only. The bidder should also supply along with his
offer the pamphlet / literatures etc. for fittings/accessories.
The bidder should not change design once offered as per A/T, Approved drawings and Type Test
Reports.
The successful Bidders shall submit complete set of Drawings of transformer in triplicate indicating
dimensions for approval and get approved it before offering 1st
stage inspection.
11.9 Performance Guarantee:
All transformers supplied against this specification shall be guaranteed for a period of 30 months
from the date of receipt at the consignee‟s Stores Center or 24 months from the date of
commissioning, whichever is earlier. However, any engineering error, omission, working
provisions, etc. which do not have any effect on the time period, shall be attended to as and when
observed / pointed out without any price implication.
50
12.0 COST DATA SHEET:-
The bidders shall submit the cost data sheets indicating the break up prices and quantity of each
raw material and components along with the unit rates required for manufacture the offered
transformers along with the offer. The cost data sheet format is enclosed herewith. If the rates
quoted are not justified with the cost data sheets, the offer shall not be considered for evaluation
and placement of the order.
13.0 NON COMPLIANCE SCHEDULE
On this schedule the bidder shall provide a list of non compliance with this specification, documenting the effects that such non compliance is likely to have on the equipment's life and operating characteristics. Each Non Compliance shall refer to the relevant clause of the specification.
Where there are no deviations from specifications, the bidder shall so indicate by stating "No deviations" in this schedule.
Clause No. Non Compliance
14.0 Type Test Certificates Schedule
14.1 On this schedule a list of the test certificates included with the bid shall be provided. Each certificate listed shall be referred to the relevant specification clause and item of equipment to which the test applies.
Sl. Particular Type Test Certificate Year of Test
No. of Test Ref
14.2 In case of any doubt in the Type test reports submitted by the bidder, the Purchaser reserves the
right to verify the original Type Test Reports, as well as to refer to the concerned laboratory directly without recourse to be bidder.
TECHNICAL SPECIFICATION FOR 16 KVA, 25 KVA, 63 KVA, 100 KVA 11/0.433 KV, STAR RATED DISTRIBUTION TRANSFORMER
PART 1: GENERAL
1. SCOPE 1.1 The specification covers the design, engineering, manufacture, stage inspection, testing, pre-delivery
inspection, supply, delivery, loading, unloading and performance requirements of 11/0.433 KV non-sealed
type aluminum wound BIS Energy Efficiency Level-2 & BEE Star-1 Distribution Transformers for outdoor use in the networks of SOUTHCO. The transformers shall be double wound, three phase, CRGO M3 Grade (0.23mm) or better, oil immersed with ONAN cooling with Oil filled up to maximum permissible level. The ratings required under this specification are 16 KVA,25 KVA, 63 KVA & 100
KVA with Aluminum windings.
1.2 The equipment offered should have been successfully type tested within five years from date of tender and the designs should have been in satisfactory operation for a period not less than three years as on the date of bid opening. Compliance shall be demonstrated by submitting with the bid, (i) authenticated copies of the type test reports and (ii) performance certificates from the users, specifically from Central Govt./ State Govt. or their undertakings.
1.3 The scope of supply should also include the provision of type test. Purchaser reserves the right to
waive type tests as indicated in the section on Quality Assurance, Inspection and Testing in this specification.
1.4 The transformer shall conform in all respects to highest standards of engineering, design, workmanship, this specification and the latest revisions of relevant standards at the time of offer and the Purchaser shall have the power to reject any work or material, which, in his judgment, is not in full accordance therewith.
2. CODES & STANDARDS 2.1 Except where modified by this specification, the transformers shall be designed, manufactured
and tested in accordance with the latest editions of the following standards. The Bidder may propose alternative standards, provided it is demonstrated that they give a degree of quality and performance equivalent to or better than the referenced standards. Whether to accept or reject any alternative standard shall be adjudged by the Purchaser. The Bidder shall furnish a copy of the alternative standard proposed along with the bid. If the alternative standard is in a language other than English, an English translation shall be submitted with the standard. In the case of conflict the order of precedence shall be 1) IEC or ISO Standards, 2) Indian Standards, 3) other alternative standards.
IEC/ISO Indian Standard Subject
IEC 71 Insulation Coordination
IEC 76 IS 2026 Power Transformers.
IS 1180(Part 1) Outdoor Three Phase Distribution Transformers up to 500 KVA, 11/ 0.4 KV, Non- Sealed Type.
IEC 137 IS 2099 Bushing for Alternating Voltages above 1000V.
IEC 156 Method of determining Electric Strength of Insulating Oils.
27 IEC 296 IS 335 Specification for Unused Mineral Insulating Oils for
Transformers and Switchgear.
IS 6792 Method of determination of electric strength of insulating oils. IEC 354 IS 6600 Loading Guide for oil immersed Transformers
IEC 437 Radio Influence Voltage Measurement.
IEC 551 Determination of Transformer and Reactor Sound Levels.
IEC 616 Terminal and Tapping markings for power transformers.
IEC 722 Guide to the Lightning and Switching impulse testing of Power Transformers and Reactors.
ISO 1460/BS 729 Galvanizing
This list is not to be considered exhaustive and reference to a particular standard or recommendation in this specification does not relieve the Supplier of the necessity of providing the goods complying with other relevant standards or recommendations.
3. SERVICE CONDITIONS
The service conditions shall be as follows:
maximum altitude above sea level 1,000m
maximum ambient air temperature 50° C
maximum daily average ambient air temperature 40° C
minimum ambient air temperature -5° C
maximum temperature attainable by an object exposed to the sun 60 ° C
maximum yearly weighted average ambient temperature 32° C
maximum relative humidity 100%
average number of thunderstorm days per annum (isokeraunic level) 70
average number of rainy days per annum 120
average annual rainfall 1500 mm
maximum wind pressure 260Kg / m2
Environmentally, the region where the equipment will be installed includes coastal areas, subject to high relative humidity, which can give rise to condensation. Onshore winds will frequently be salt laden. On occasions, the combination of salt and condensation may create pollution conditions for outdoor insulators.
Therefore, outdoor material and equipment shall be designed and protected for use in exposed, heavily polluted, salty, corrosive, tropical and humid coastal atmosphere.
4. SYSTEM CONDITIONS:
The equipment shall be suitable for installation in supply systems of the following characteristics.
Frequency 50 Hz ± 5%
Nominal system voltages 11 KV System 11 KV
LV System 433/250 V
Maximum system voltages 11 KV System 12 KV
28
LV System 476 V
Minimum LV voltage (NEC) 392 V
Nominal short circuit apparent power of 11 KV System 500 MVA (IS: 2026)
the system
Insulation levels :
1.2/50 µ sec impulse withstand 11 KV System 95 KV peak (As Per
BEE, Clause No.10 )
Power frequency one minute withstand 11 KV System 28 KV (rms)
(wet and dry)
LV System 3 KV (rms)
Neutral earthing arrangements : LV System Solidly earthed 29
PART 2: TECHNICAL SPECIFIC TECHNICAL REQUIREMENTS 1 Rated KVA (ONAN rating) 2 No. of phases 3 Type of installation 4 Frequency 5 Cooling medium 6 Type of mounting 7 Rated voltage
a) High voltage winding b) Low voltage winding
8 Highest continuous system voltage a) Maximum system voltage ratio (HV / LV ) b) Rated voltage ratio (HV / LV )
9 No. of windings 10 Type of cooling 11 KVA Rating corresponding to
ONAN cooling system 12 Method of
connection: HV: LV:
13 Connection symbol 14 System earthing 15 Percentage impedance voltage on normal
tap and KVA base at 750 C corresponding
to HV/ LV rating and applicable tolerances :
16 Intended regular cyclic overloading
of windings 17 a) Anticipated unbalanced loading
b) Anticipated continuous loading of windings (HV / LV)
18 a) Type of tap changer
b) Range of taping 19 Neutral terminal to be brought out 20 Over Voltage operating capability
and duration 21 Maximum Flux Density in any part of the
core and yoke at rated KVA, rated voltage i.e 11 KV / 0.433 KV and system frequency of 50 HZ
22 Insulation levels for windings :-
16 KVA,25KVA. 63 KVA, 100 KVA
11/0.433 KV 3 Outdoor
50 Hz (± 5% ) Insulating Oil (ONAN)
On Channels.
11 KV 0.433 KV
12 KV / 0.476 KV 11 KV / 0.433 KV
Two winding Transformers
ONAN ( Oil natural / Air natural ) 100%
Delta Star
Dyn 11 Neutral of LV side to be solidly earthed.
28.3 Impedance + Tolerance %
+ 10% (No negative tolerance will be allowed)
As per IEC –76-1, Clause 4.2
Around 10%
110 % of rated current
NA
No Tap
On LV side only
112.5 % of rated voltage ( continuous )
1.5 Tesla
30
a) 1.2 / 50 microsecond wave shape Impulse withstand (KVP)
b) Power frequency voltage withstand
(KV-rms) 23 Type of winding insulation
a) HV winding
b) LV winding 24 Withstand time for three phase short circuit 25 Noise level at rated voltage and frequency 26 Permissible Temperature Rise over
ambient temperature of 500C
a) Of top oil measured by thermometer.
b) Of winding measured by resistance. 27 Minimum HV clearances in air (mm) :-
a) Phase to Phase
b) Phase to ground 28 Bushings & Terminals
a) HV winding line end
b) LV winding
29 Insulation level of bushing
a) Lightning Impulse withstand (KVP)
b) 1 Minute Power Frequency withstand voltage (KV –rms )
c) Creepage distance (mm) (minimum)
30 Material of HV & LV Conductor 31 Maximum current density for HV and
LV winding for rated current
32 Polarisation index i.e. ratio of megger
values at 600 sec. to 60 sec for HV to earth, L.V to earth and HV to LV.
33 Core Assembly
34 Transformer Max. Losses at 50%
rating load (Watts).
a) 25 KVA 190
b) 63 KVA 340
c) 100 KVA 475
d)
6. 16 KVA 135
TYPE OF TRANSFORMER
HV: 95 LV: N.A.
HV: 28 LV: 03
Uniform
Uniform
2 Seconds
As per NEMA Publication No. TR-1.
350C
400 C
280
140
12 KV oil filled porcelain communicating
type of bushings ( Antifog type )
0.4 KV porcelain type of bushing (Antifog type)
HV LV
95 Not applicable
28 3
25 mm/ KV
EC grade Aluminum
1.6 Amp/ mm2.
Shall be greater than or equal to 1.5, but less than or equal to „5‟.
Boltless type
Max. Losses at 100%
load (Watts).
635
1140
1650
440
31
6.1 The transformers shall be of core type construction, double wound, three phase,
oil immersed, 11/0.433KV, 50 Hz with natural oil and air cooling (ONAN) to
be used as step down transformers for out door use. The design of the tank,
fittings, bushings, etc shall be such that it will not be necessary to keep the
transformer energised to prevent deterioration as the transformers may be held
in reserve, outdoors, for many years.
7. PERFORMANCE , CAPACITY AND SHORT CIRCUIT RATINGS
7.1 The following ratings are covered under this specification
16 KVA,11/0.433KV,Aluminium wound
25 KVA,11/0.433 KV, Aluminum wound
63 KVA,11/0.433 KV, Aluminum wound
100 KVA,11/0.433 KV, Aluminum wound
7.2 The transformer shall be capable of supplying a continuous load equal to its
KVA rating, under the following conditions :
continuous steady load;
design at maximum ambient air temperature of 500C;
400 C average winding temperature rise and 35
0C top oil temperature rise
for conventional breathing transformers.
7.3 The transformer may be overloaded during emergency up to 150% of its
continuous rating in accordance with IEC Publication 354 or IS: 6600. Bushings
and other current-carrying parts shall also be designed for this condition.
7.4 The transformer shall be capable of withstanding for two seconds without
damage to any external short circuit, with the short circuit MVA available at the
terminals of either winding with rated voltage on the other winding. If short
circuit tests have been carried out on the particular design of transformer
7.5 offered, the test results shall be supplied with the bid.
7.6 The thermal ability to withstand short circuit shall be demonstrated by
calculation.
The transformer shall be capable of withstanding the thermal and dynamic
7.7 effects of short circuits, as specified in IEC 76-5 or IS: 2026: Ability to
withstand short circuits.
32
The maximum flux density in any part of the core and yoke at rated KVA,
Voltage and frequency shall not exceed 1.5 Tesla.
8. VOLTAGE RATIO & TAPPING RANGE
8.1 The transformers shall have the following ratio :-
the nominal voltage ratio shall be 11,000/ 433 V for 16 KVA 25 KVA, 63
KVA, 100
KVA 11/0.4KV transformers;
Tolerance on the voltage ratio shall be ± 0.5%.
for transformers up to 100 KVA, 11/0.4 KV no tap changer is required.
8.2 The bidder shall state in the technical schedule, the percentage regulation at full
load, power factor 1.0 and at full load, power factor 0.85 lagging.
Transformers shall be suitable for parallel operation with each other.
9. PERCENTAGE IMPEDANCE
9.1
The Percentage of Impedance at 75 0 C shall be 4.5 % for 16 KVA,25 KVA,63
KVA &
100 KVA transformers. No negative tolerance on percentage Impedance is
allowed.
10 LOSSES
The load losses shall not exceed the values given
below:-
KVA Rating Maximum losses at Maximum losses at
50% loading (Watts) 100% loading (Watts)
25 KVA 190 635
63 KVA 340 1140
100 KVA 475 1650
16 KVA 135 440 4.1 The above losses are maximum allowable and there should not be any positive
tolerance.
4.2 The offered transformer(s) should have been type-tested at CPRI/ NABL
Accredited laboratory. The bid shall be accompanied with type-test reports
(short circuit test and Impulse test) conducted at Central Power Research
Institute / NABL Accredited laboratory for the offered transformers within five
years from date of tender. The short circuit test report(s) must contain the
measured no load loss and load loss, determined by CPRI/ NABL Accredited
laboratory.
In case of any doubts, SOUTHCO reserves the right to verify the original type
test reports of CPRI/ NABL Accredited laboratory or ask the supplier to
conduct the type tests at CPRI/ NABL Accredited laboratory at his
(supplier‟s) cost for re-confirmation of the test results particularly no load
losses, load losses and percentage impedance.
5.1 If the bidder quotes lower values of losses than the CPRI‟s measured losses, he
has to prove the same by conducting the Impulse & short Circuit tests at CPRI/
NABL Accredited laboratory along with measurement of no load losses and
load losses at his own cost in presence of Purchaser‟ s authorized representative
without any financial liability to Purchaser.
5.2 However, if the loss figures will exceed the stipulated values as per
specification, the transformer(s) shall be out rightly rejected.
11. VECTOR GROUP
11.1 The transformers shall be connected delta-star, in accordance with vector group
reference Dyn11 of IEC - 76/ IS - 2026.
11.2 The LV neutral shall be brought out to a terminal bushing, which shall be
identical to the phase bushings in all respects.
12. LOSSES
12.1 Transformers would be out rightly rejected if losses exceed the values indicated
at clause-10 above.
13. FLUX DENSITY
The flux density at rated voltage & rated frequency shall not exceed. 1.5 Tesla. The
transformer must be capable of operating at 10% over voltage and at frequency of 48.5
Hz without saturation.
vii) INSULATION LEVELS
The insulation levels as defined in IEC 76-C/ IS: 2026 Insulation levels and dielectric
test shall apply as per Table 2:
Table 2 : Transformer insulation level
HV Winding LV Winding
Basic Impulse voltage Level (Kvp) (1.2/50 micro. sec. 95 Not
Wave ) Applicable
Power Frequency voltage withstand level, Wet and Dry 28 3
(KV)
Bushings and terminals shall be adequate for the winding insulation tests and shall flash
over externally before puncture or internal failure can occur.
2 NOISE LEVEL
The average noise level of the transformers shall not exceed 51db. The measurement
shall be carried out in accordance with IEC 551 at a distance of 300mm from the
envelope of the transformer.
3 RADIO INFLUENCE VOLTAGE
The maximum radio influence voltage shall be 250µ V, measured as specified in IEC
437.
17 CORE AND WINDINGS
17.1 Core
17.1.1 Stage level inspection for core construction shall be carried out by the owner.
Each lamination shall be insulated such that it will not deteriorate due to mechanical pressure 17.1.2 and the action of hot transformer oil.
17.1.3 The core shall be constructed from high grade, non-ageing, Cold Rolled Grain
Oriented (CRGO) silicon steel of M3 Grade (0.23mm) or HIB grade laminations
only. No other core materials shall be entertained. Bidders are requested to note that
35
only PRIME CORE M3 Grade (0.23mm) materials HIB grade are to be used. In no
case, second grade core material is to be used. The purchaser at his discretion, may
select samples from the core laminations and get the same tested in CPRI/ NABL
Accredited laboratory to prove the quality of the core material.
17.1.4 For the above purpose, the supplier shall have to offer every batch of core laminations
received from his Sub-Vendor along with Invoice of the sub-vendor, Mills test
certificate, packing list, Bill of landing, Bill of entry certificate to customs etc. towards
proof of prime core materials for verification by the Purchaser‟s representative without
any cost to the Purchaser. Besides, the contractor must mention in his bid about the type
of CRGO / Amorphous laminations to be utilized for the offered transformers along
with a copy of the specific core loss curve at different flux densities.
17.1.5 Core materials should be directly procured either from the manufacturer or through their
accredited marketing organization of repute, but not through any agent.
The core and winding shall be capable of withstanding shocks during transport,
installation and service. Provision shall be made to prevent movement of the core and
windings relative to the tank during these conditions and also during short circuits.
17.1.6 The design shall avoid the presence of pockets which would prevent the complete
emptying of the tank through the drain valve. The core material offered in the tender to
be checked for its correctness before core coil assembly. For this, the tendered must ask
for core and coil inspection before its tanking.
17.1.7 The laminations shall be free of all burrs and sharp projections. Each sheet shall have an
insulting coating resistant to the action of hot oil.
17.1.8
The insulation structure for the core to bolts and core to clamp plates shall be such as to withstand 2000 V DC voltage for one minute.
17.1.9 The completed core and coil shall be so assembled that the axis and the plane of the outer surface of the core
assemble shall not deviate from the vertical plane by more than 25mm.
17.1.10 All steel sections used for supporting the core shall be thoroughly shot or sand blasted, after cutting, drilling and welding.
17.1.11 The finally assembled core with all the clamping structures shall be free from deformation and shall not vibrate
during operation.
17.1.12 The core clamping structure shall be designed to minimize eddy current loss.
17.1.13 The framework and clamping arrangements shall be securely earthed.
36
17.1.14 The core shall be carefully assembled and rigidly clamped to ensure adequate mechanical strength.
17.1.15 Oil ducts shall be provided, where necessary, to ensure adequate cooling inside the core. The welding structure and
major insulation shall not obstruct the free flow of oil through such ducts.
17.1.16 The design of magnetic circuit shall be such as to avoid static discharges, development of short circuit paths within itself or to the earth clamping structure and production of flux component at right angle to the plane of the lamination, which may cause local heating. The supporting framework of the cores shall be so designed as to avoid the presence of pockets, which would prevent complete emptying of the tank through the drain valve or cause trapping of air during filling.
The construction is to be of boltless core type. The core shall be provided with lugs
17.1.17 suitable for lifting the complete core and coil assembly. The core and coil assembly
shall be so fixed in the tank that shifting will not occur during transport or short circuits.
17.2 INTERNAL EARTHING
All internal metal parts of the transformer, with the exception of individual laminations 17.2.1
and their individual clamping plates shall be earthed.
The top clamping structure shall be connected to the tank by a copper strap. The bottom 17.2.2
clamping structure shall be earthed by one or more the following methods:
17.2.3
17.2.4
a) By connection through vertical tie-rods to the top structure.
b) By direct metal to metal contact with the tank base. c) By a connection to the structure on the same side of the core as the main earth
connection to the tank.
The magnetic circuit shall be connected to the clamping structure at one point only and
this shall be brought out of the top cover of the transformer tank through a suitably rated
insulator. A disconnecting link shall be provided on transformer tank to facilitate
disconnections from ground for IR measurement purpose.
Coil clamping rings of metal at earth potential shall be connected to the adjacent core
clamping structure on the same side as the main earth connections.
17.3 Windings
17.3.1 Winding shall be subjected to a shrinking and seasoning process, so that no further shrinkage
occurs during service. Adjustable devices shall be provided for taking up possible shrinkage in service.
17.3.2 All low voltage windings for use in the circular coil concentric winding shall be wound
37
on a performed insulating cylinder for mechanical protection of the winding in handling
and placing around the core. 17.3.3
Winding shall not contain sharp bends which might damage the insulation or produce
high dielectric stresses. No strip conductor wound on edge shall have width exceeding
six times the thickness. 17.3.4
The winding insulation shall be free from insulating compounds which are liable to
soften, ooze out, shrink or collapse. It shall be non catalytic and chemically inert in hot
transformer oil during normal service. 17.3.5
The stacks of windings are to receive adequate shrinkage treatment. 17.3.6
The windings and connections are to be braced to withstand shocks during transport,
switching, short circuit or other transient conditions. 17.3.7 Permanent current carrying joints in the windings and leads shall be welded or brazed.
17.3.8 Clamping bolts for current carrying parts inside oil shall be made of oil resistant material which
shall not be affected by acidity in the oil steel bolts, if used, shall be suitably treated.
Terminals of all windings shall be brought out of the tank through bushings for external
17.3.9 connections.
The windings shall be uniformly insulated and the L.V neutral points shall be insulated
17.3.10 for full voltage.
The completed core and coil assemble shall be dried in vacuum at not more than 0.5mm of
mercury absolute pressure and shall be immediately impregnated with oil after the drying
process to ensure the elimination of air and moisture within the insulation. Vacuum may be
applied in either vacuum over or in the transformer tank.
17.3.11 The winding shall be so designed that all coil assembles of identical voltage ratings
shall be interchangeable and field repairs to the winding can be made readily without
special equipment. The coils shall have high dielectric strength.
17.3.12 Coils shall be made of continuous smooth high grade electrolytic copper or aluminium
conductor, shaped and braced to provide for expansion and contraction due to temperature
changes.
Adequate barriers shall be provided between coils and core and between high and low voltage
17.3.13 coil. End turn shall have additional protection against abnormal line disturbances.
The insulation of winding shall be designed to withstand voltage stress arising from
17.3.14 surge in transmission lines due to atmospheric or transient conditions caused by
switching etc 17.3.15 Tapping shall not be brought out from inside the coil or from intermediate turns and
shall be so arranged as to preserve as far as possible magnetic balance of transformer at
all voltage ratios.
17.3.16 Magnitude of impulse surges transferred from HV to LV windings by electro magnetic
induction and capacitance coupling shall be limited to BIL of LV winding.
17.3.17 The winding conductor shall be of Aluminum. The current density shall not exceed 1.6
Amp/ mm2 for aluminium at normal full load current.
6.7.2 BUSHINGS AND TERMINATIONS
6.7.5 Bushings
18.1.1 Bushings shall be of the outdoor type and easily replaceable. Cemented in types will not
be accepted. They shall be sufficiently robust to withstand normal transport and erection
hazards and shall confirm to IEC 137 /IS 3347 and 2099.
18.1.2 All bushings shall have a minimum creepage distance of 25 mm /KV and shall have a
continuous rating of 200% of the transformer rating. The protected creepage distance
shall not be less than 50% of the total.
The following minimum 11 KV clearance shall be provided:
External (Air) for 11 KV
Phase to phase 255 mm
Phase to earth 140 mm
18.1.3 The 11 KV bushings of transformers shall be provided with a bi-metallic terminal
connector or suitable device to receive 35 –100 mm2 AAAC or ACSR conductor
directly without any bi-metallic action. The dia of HT bushing stud should not be less
than 12.5 mm. 18.1.4
The secondary bushings of transformers shall be fitted with non ferrous threaded
terminals of dia not less than 20 mm. With the exception of brass the terminals shall be
protected from atmospheric deterioration by suitable tinning or by some other approved
coating. 18.1.5 The terminals are to be supplied with one 16mm bolt, one conic spring washer, one
matching flat washer, one nut and one lock nut for each hole in the terminal plate.
18.2 Bushing Labels
18.2.1 The HV bushings shall be labeled U, V and W and the LV bushing u, v, w and n.
Marking letters shall be at least 12 mm high. The means of marking shall be either,
engraved metal plate; or
etched anodized aluminum.
Phase identification by adhesive stickers shall not be acceptable. 18.2.2 If labeling is to be carried out on the tank, it is preferred that one plate be used rather
than individual markings for each phase, in order to prevent incorrect phase markings.
Labels shall conform to the requirements of the section on labels in this specification.
18.3 Earthing Terminals
All transformers shall be provided with two earthing terminals conforming to relevant
Standards and M12 ISO metric bolt and nut which shall be non ferrous. It shall include a
spring washer and lock washer.
18.4 LIGHTNING ARRESTORS
9 KV, 5KA metal oxide lightning arresters of reputed make conforming to IS-3070
Part-III, one number per phase shall be provided.(Under the HV bushing with GI
earth strip 25x4 mm connected to the body of the transformer with robust
clamping arrangement). Lightening arrestors with polymer insulators in
conformance with relevant IEC can also be used. 19 TANK FABRICATION
19.1 All transformer sizes, the tank shall be of bolted type construction in accordance with IS
1180 (Part 2).
The tank shall be at atmospheric pressure at an internal temperature of 100 C;
The tank shall be designed for an internal pressure of 100 Kg/ m2 at 50
0 C
ambient conditions. It shall be capable of withstanding an unlimited number of 24 hours cyclic variations of internal pressure from atmospheric to this value.
The tendered shall state the top oil temperature at which the tank internal
pressure shall reach the value of 100 kN/ m2 and the value of steady load which
will result in this top oil temperature with an ambient temperature of 450 C.
Adequate space shall be provided at the bottom of the tank for collection of sediments.
19.2 Transformer tanks of all types shall be designed so that the completed transformer can
be lifted and transported without permanent deformation or oil leakage. Stiffeners
provided on all the four side walls for rigidity should be so designed that there is no
accumulation of water.
19.3 The Tank shall be of rectangular shape with round edges fabricated from tested quality
mild steel plates with minimum thickness of 3.15 mm. for the side walls while top cover
and the bottom plate of the tank shall have a minimum thickness of 5 mm. The
transformer tank and the top cover shall be designed in such a manner as to leave no
external pockets in which water can log, or any internal pocket where air/ gas can
accumulate.
Edge of Top cover should be bend downwards so as to avoid water through cover plate
gasket. The width of the bend plate shall be 25mm minimum.
19.4 All sealing washers / gaskets shall be made of oil and heat resistant neoprene rubber or
neoprene bonded cork seals suitable for temperature as stipulated in this specification.
Surfaces at gasketted joints shall be such that an even face is presented to gasket,
thereby eliminating the necessity for the gasket to take up surface irregularities.
19.5 All pipes, radiators, stiffeners or corrugations which are welded to the tank wall shall be
welded externally and shall be double welded wherever possible. All welds shall be
stress relieved. 19.6 The transformer tank shall be complete with all accessories, lifting lugs etc. and shall be
designed to allow the complete transformer filled with oil to be lifted by crane or jacks
without risk of any damage and can be transported by Rail/ Road without straining any
joints and without causing any leakage of oil. 19.7 Provision of Cable End Box with suitable gland. 19.8 The height of the tank shall be such that minimum vertical clearance up to the top cover
plate of 80mm is achieved from the top of the yoke.
20 PRESSURE RELIEF DEVICE
Transformers shall be fitted with a pressure relief device in the form of explosion vent.
The tendered shall state the pressure at which it is designed to operate. 21 OIL LEVEL GAUGE
A suitable oil level gauge (Magnetic type of dia 100 mm) shall be fitted on the
transformers and so located that it can be easily read from ground level. The gauge fitted
with the conservator shall be graduated for temperatures of 50 C, 30
0 C and +98
0 C.
22 CONSERVATORS AND BREATHERS
All the transformers shall be provided with a conservator tank. 8.7.6 The conservator tank shall be so designed and located as to eliminate any trapping of air
in the transformer or pipe work. It shall be inclined at an angle of about 5 degrees to the
horizontal towards the drain plug and the pipe connecting the main tank to the
conservator should project about 20 mm above the bottom of the conservator so as to
create a sump for the collection of impurities. Minimum oil level corresponding to 50 C
shall be well above the sump level. 22.2
All transformers shall be fitted with a silica gel breather of weatherproof design at a
convenient height with oil seal at the bottom, draw in plug and filling holes with covers
to isolate the silica gel from the atmosphere. The breather pipe should be connected at
top of the conservator tank with two bends at right angles. The cover of the main tank
and bushings turrets shall be provided with air release plug to enable the trapped air to
be released.
23 FITTINGS AND ACCESSORIES 8.9 The following standard fittings and accessories shall be provided :
Rating, diagram and terminal marking plate. Two earthing terminals. Lifting lugs/ platform lugs.
Pressure relief device or explosion vent. Silica gel breather.
A magnetic oil level gauge 100 mm dia for all transformers indicating three position
( 3) of oil - minimum. 5 0 C, 30
0 C and 98
0 C.
Top filter valve with locking arrangement. Bottom filter valve with locking arrangement. Air release plugs at transformer top cover, bushing turrets etc.
Set of Radiators. Conservator Tank
Bi-metallic terminals on the bushings for connection with over head ACSR/ AAAC
conductor. The Specification and brief details of the salient features of these terminals
should be stated. 25 TRANSFORMER OIL
The transformers shall be supplied complete with first filling of transformer oil upto
maximum permissible level. The quantity of oil required for the first filling of the
transformer and its full specification shall be stated in the bid. The complete first filling
shall be of new oil free from inhibitors and additives up to maximum permissible level
for the supplied Transformer. The bidder shall quote the price of transformer including
the cost of Transformer Oil required for initial filling.
The insulating oil for the transformer shall be of EHV grade, generally conforming to
IEC: 296/ BS: 148/ REC: 39/ 1993 or latest version of IS: 335/ 1983 whichever is more
stringent. No inhibitors shall be used in the oil. The dielectric strength of the oil shall
not be less than 60 KV at 2.5 mm. gap when tested in accordance with IS: 6792/ 1972.
If an anti-oxidant inhibitor is recommended, its use shall be subject to the purchaser‟s
approval.
The design and materials used in the construction of the transformer shall be such as to reduce the risk of the development of acidity in the oil.
The contractor shall warrant that oil furnished is in accordance with the following
specifications.
S.No Characteristic Requirement Method of Test
01 Appearance The oil shall be clear & A representative sample of oil transparent&freefrom shall be examined in a 100 mm suspended matter or sediment thick layer at ambient temp.
02 Density at 200C 0.89 g/cm
3 Max. IS:1448
03 Kinematic Viscosity at 27 27 CST IS:1448 deg. C Max
04 Interfacial tension at 0.03 N/m IS:6104 27deg.C Min.
05 Flash Point 136 0C IS:1448
06 Pour Point Max. -6 0C IS:1448
07 Naturalization Value 0.03 mg KOH/gm IS:335 (Total Acidity) Max.
08 Electric strength 72.5 KV IS:6792 Breakdown (voltage) Min.
09 Dielectric dissipation 0.03 Max IS:6262 factor tan delta at 90
0 C
10 Min specific resistance 35X1012
ohm cm (min.) IS:6103 (resistively) at 90 deg.C
11 Oxidation stability
12 Neutralization value after 0.40mg KOH/g
oxidation
13 Total sludge after 0.10% by weight max.
oxidation
14 Presence of oxidation The oil shall not contain anti- IS:335 Inhibitor oxidant Additives.
15 Water content Max: Less than 25ppm IS:2362
26 RATING AND CONNECTION PLATE
Each transformer shall be provided with a rating plate of weatherproof material showing
the following items indelibly marked :
type of transformer
standard to which it is manufactured (preferably IEC 76)
manufacturer‟s name
transformer serial number
year of manufacture
rated frequency in Hz (50)
rated voltages in KV (11/0.433)
number of phases (3)
rated power in KVA
type of cooling (ONAN)
rated currents in A
vector group symbol (Dyn11)
1.2/50µs wave impulse voltage withstand level in KVp
power frequency withstand voltage in KV
impedance voltage at rated current and frequency in percentage at 75 0 C at normal
tap
Measured load loss in KW at rated current and at 75 0 C at normal tap
Measured no-load loss in KW at rated voltage and rated frequency
continuous ambient temperature at which ratings apply in 0C
top oil and winding temperature rise at rated load in 0C
winding connection diagram
Total weight in kg with complete oil filled.
total weight of the transformer with out oil
Volume of oil in litres.
weight of core and windings in kg; and
name of the purchaser
DISCOM, GoO, CAPEX Programme.
The rating plate shall conform to the requirements of the section of Labels in this
specification.
27. BASE MOUNTING ARRANGEMENT
The under base of all transformers up to 100 KVA capacity shall be provided with two
75x40 mm channels, 460 mm long with holes of 14 mm dia at a centre to centre distance
of 415 mm to make them suitable for fixing on a platform or plinth.
27 (a) PUNCHINGS: Non-erasable Punching and embossing of Volume of oil in litres, name of
the Purchaser- WESCO & SOUTHCO, Orissa, Name of the Supplier – M/s ------------
-------------------, Year of Manufacture, Guarantee Period ( i.e. 2 years from the date of
installation ) and Sl. No. of each transformer is to be made on top core channel, top
cover, side walls and name plates of transformers.
27 (b) 3 STAR LEVEL: In addition to above, the supplied Distribution Transformers must
contain 3 Star Level with style and information provided by the Bureu of Energy
Efficiency (B.E.E), Ministry of Power, Government of India.
28. PAINTING
10.2 All paints shall be applied in accordance with the paint manufacturer‟s recommendations. Particular attention shall be paid to the following:
10.3 a) Proper storage to avoid exposure as well as extremes of temperature.
Surface preparation prior to painting.
Mixing and thinning Application of paints and the recommended limit on time intervals between coats.
Shelf life for storage.
28.3 All paints, when applied in normal full coat, shall be free from runs, sags, wrinkles, patchiness, brush marks or other defects.
28.3.1 All primers shall be well marked into the surface, particularly in areas where painting is evident,
and the first priming coat shall be applied as soon as possible after cleaning. The paint shall be applied by airless spray according to the manufacturer‟s recommendations. However, wherever airless spray is not possible, conventional spray be used with prior approval of purchaser.
28.3.2 The supplier shall, prior to painting protect nameplates, lettering gauges, sight glasses, light
fittings and similar such items. 28.4 Cleaning and Surface Preparation 28.4.1 After all machining, forming and welding has been completed, all steel work surfaces shall be
thoroughly cleaned of rust, scale, welding slag or spatter and other contamination prior to any painting.
28.4.2 Steel surfaces shall be prepared by Sand/Shot blast cleaning or Chemical cleaning by Seven tank
process including Phosphating to the appropriate quality.
28.4.3 The pressure and Volume of the compressed air supply for the blast cleaning shall meet the work
requirements and shall be sufficiently free from all water contamination prior to any painting. 28.4.4 Chipping, scraping and steel wire brushing using manual or power driven tools cannot remove
firmly adherent mill-scale and shall only be used where blast cleaning is impractical. 28.5 Protective Coating
28.5.1 As soon as all items have been cleaned and within four hours of the subsequent drying, they shall
be given suitable anticorrosion protection. 10.5 Paint Material
Followings are the type of paints that may be suitably used for the items to be painted at shop and supply of matching paint to site:
i Heat resistant paint (Hot oil proof) for inside surface.
ii For external surfaces one coat of Thermo Setting Paint or 2 coats of Zinc chromate followed by 2
coats of P.U (Poly-urethene) paint. The color of the finishing coats shall be dark admiral gray.
10.6 Painting Procedure
All painting shall be carried out in conformity with both specifications and with the paint
manufacture‟s recommendations. All paints in any one particular system. Whether shop or site applied, shall originate from one paint manufacturer.
Particular attention shall be paid to the manufacture‟s instructions on storage, mixing, thinning
and pot life. The paint shall only be applied in the manner detailed by the manufacturer e.g. brush, roller, conventional or airless spray and shall be applied under the manufacturer‟s recommended conditions. Minimum and maximum time intervals between coats shall be closely followed.
All prepared steel surfaces should be primed before visible re-rusting occurs or within 4 hours
whichever is sooner. Chemical treated steel surfaces shall be primed as soon as the surface is dry and while the surface is warm.
46
Where the quality of film is impaired by excess film thickness, (wrinkling, mud cracking or general softness) the supplier shall remove the unsatisfactory paint coatings and apply another. As a general rule, dry film thickness should not exceed the specified minimum dry film thickness by more than 25%. In all instances, where two or more coats of the same paints are specifies, such coatings may or may not be of contrasting colors.
Paint applied to items that are not be painted, shall be removed at supplier‟s expense, leaving the
surface clean, un-stained and undamaged. 10.6 Damages to Paints Work
Any damage occurring to any part of the painting scheme shall be made good to the same standard of corrosion protection and appearance as that originally employed.
Any damaged paint work shall be made as follows:
The damaged area, together with an area extending 25mm around its boundary, shall be cleaned down to bare metal.
A priming coat shall immediately applied, followed by a full paint finish equal to that originally applied and extending 50mm around the perimeter of the originally damaged.
The repainted surface shall present a smooth surface. This shall be obtained by carefully chamfering the paint edges before & after priming.
28.9 Dry Film Thickness
To the maximum extent practicable, the coats shall be applied as a continuous film of uniform thickness and free of pores. Over-spray, skips, runs, sags and drips should be avoided. The different coats may or may not be same color.
Each coat of paint shall be allowed to harden before the next is applied as per manufacture‟s recommendations. Particular attention must be paid to full film thickness at edges.
The requirement for the dry film thickness(DFT) of paint and the material to be used shall be as given below:
Sl. Paint Type Area to be No of Total Dry film No painted Coats thickness(Min) 1. Liquid paint
a) Zinc Chromate Out side 01 30 micron (Primer)
b) P.U. Paint (Finish Out side 02 45 each Coat)
c) Hot Oil paint inside 01 35/10 micron
The colour of the finishing coat shall be Sky Blue/ Dark Admiral Gray/ Deep Green or
any other colour as decided by the Purchaser 29 SEALING GASKETS
All sealing washers / gaskets shall be made of oil and heat-resistant Nitrile/ Neoprene rubber/
synthetic rubber bonded cork type RC-70C gaskets. Gaskets made of natural rubber or cork
sheet are not permissible.
30 SUPRESSION OF HARMONICS 47
The transformer shall be designed with attention to the suppression of harmonic voltage,
especially the third and fifth. 31 TESTS 31.1 Routine Tests
Routine tests shall be carried out on all transformers and the tests shall be conducted in
accordance with relevant National/ International Standards. No sampling is allowed. In
addition, tank tests in accordance with IS: 1180 shall be carried out.
The following routine measurements and tests shall be carried out in presence of Purchaser‟s
authorized representative(s):
a) Measurement of winding resistance.
b) Voltage ratio measurement and check of polarity and vector group. Bushing positions
shall have permanent markings at this stage of production;
c) measurement of impedance voltages/ short circuit impedance at rated current and
frequency
d) measurement of load loss at full load and 750C;
e) measurement of neutral unbalance current;
f) Temperature rise test on one transformer of each rating and measurement of hot
resistance.
g) measurement of no-load loss and no-load currents at full, 50%, 75%, 90%, 110%, 112.5%
and 120% of rated voltages;
h) induced over voltage withstand test at 22KV for 60 sec on the HV windings;
i) power frequency voltage withstand tests on HV and LV windings;
j) magnetic balance test
k) Polarization Index test P.I. value shall be not less than 1.5. P.I. = IR at 600 sec / IR at 60
sec.
l) oil leakage test : The criterion of leakage shall be discoloration by oil of whitewash
applied externally to suspected parts at an oil temperature of 900C or other method, as
approved by the Purchaser;
m) Pressure test on transformer tank on one unit for each rating.
Bushings and oil shall be subject to the following routine
tests. n) bushing routine test: in accordance with IEC 137/IS 3347;
48
o) Oil dielectric and moisture content test: conforming to IEC 156 or IS 335.
Routine test certificates shall include in addition to the test results, the purchaser‟s order
number, the transformer serial number, outline drawing number and transformer KVA rating.
Any other applicable tests shall be conducted at the discretion of the Purchaser without any
extra cost to Purchaser.
31.2 Type Tests 31.2.1 The measurements and tests should be carried out in accordance with the standard specified in
each case as indicated in the following table if the same tests were not conducted earlier at
CPRI or any NABL accredited Laboratory on the transformers of the offered design.
Table 6: Transformer type tests
Type Test Standard
Temperature Rise Test IEC 76/IS
2026/IS6600
Impulse Voltage Withstand Test, including Full Waves and IEC 76/IS 2026 Chopped Waves as listed below
Noise Level Measurement IEC 551
Short Circuit Test IEC 76 / IS 2026
In accordance with IEC 76-3 the following sequence of impulses should have been/
should be applied;
one full wave at 50% BIL; one full wave at 100% BIL; one chopped wave at 50% BIL
two chopped waves at 100% BIL and two full waves at 100% BIL.
31.2.2 If the type test report(s) submitted by the bidder do not fulfill the criteria, as stipulated
in this technical specification/ Bidder‟s offer, the relevant type test(s) has/ have to be
conducted by the Bidder at his own cost in CPRI/ NABL accredited laboratory in the
presence of purchasers representative(s) without any financial liability to purchaser in
the event of order placed on him.
11.4 Even if the Type test report(s) confirm(s) the Purchaser‟s specification, the Purchaser at
his discretion may ask the Supplier to repeat any or all specified type tests at CPRI/
NABL accredited laboratory on sample(s), selected at random by the purchaser‟s
representative(s) out of the offered quantity (first lot i.e. minimum one third of the total
ordered quantity). The type test(s) are to be test-witnessed by the Purchaser‟s
representative(s). For such type of repetition of type tests, the Bidder may quote Type
Test Charges in the enclosed Price Schedule or conduct the tests free of cost. 11.5 The supplier shall furnish calculations in accordance with IS: 2026 to demonstrate the
Thermal ability of the transformers to withstand Short Circuit forces.
31.3 CHALLENGE TESTING:
The manufacturer can also request challenge testing for any test based on the
specification and measurement of no load losses, load losses & impedance at 750C. The
challenger would request for testing with testing fees. The challenge test fees are
proposed to be at least three times the cost of testing. This is likely to deter unnecessary
challenges. The challenger would have the opportunity to select the sample from the
store and any such challenge should be made within the guarantee period. The party
challenged, challenger and the utility could witness the challenge testing.
The challenge testing would cover the following tests:
1. Measurement of magnetizing current & No Load losses at rated voltage & frequency.
2. Load Losses at more than 50% loading to determine the Full Load losses &
percentage impedance at 750C and neutral unbalance current.
3. Temperature Rise Test.
The challenge test could be conducted at NABL Laboratory like ERDA and CPRI. If the
values are within the limits the product gets confirmed else not confirmed. No positive
tolerances in losses are permitted. If the product is not confirmed the manufacturer
would pay the challenge fee and the challenger would get the fee refunded. However as
a redressal system the challenged would be allowed to ask for fresh testing of two or
more samples from the store and the same be tested in NABL Laboratory or CPRI in
presence of the party challenged, challenger and the utility.
If any one of the above two samples does not confirm the test, then the product is said to
have failed the test. In such cases the manufacturer will be declared as unsuccessful
manufacturer for the said product with wide publicity and would not be allowed to
compete in tenders of the purchaser for a period of at least three years and heavy penalty
would be imposed.
31.4 TEST VOLTAGE
Transformers shall be capable of withstanding the Power frequency and Impulse test
voltage as described below:
Nominal Highest Impulse Test Power frequency test
system voltage System voltage voltage voltage
433 V (rms) 3 KV (rms)
11 KV (rms) 12 KV (rms) 95 KV (Peak) 28 KV (rms)
32 COMPLIANCE WITH SPECIFICATION
The transformers shall comply in all respects with the requirements of this specification.
However, any minor departure from the provisions of the specification shall be disclosed
at the time of tendering in the Non Compliance Schedule as in Annexure-3, Section- V of
this document.
33 COMPLIANCE WITH REGULATIONS
All the equipment shall comply in all respects with the Indian Regulations and acts in
force.
The equipment and connections shall be designed and arranged to minimize the risk of
fire and any damage which might be caused in the event of fire.
34 INSPECTION AND TESTING 34.1 The Purchaser shall have free entry at all times, while work on the contract is being
performed, to all parts of the manufacturer‟s works which concern the processing of the
equipment ordered. The manufacturer shall afford the Purchaser without charge, all
reasonable facilities to assure that the equipment being furnished is in accordance with
this specification. After approval of Drawings by the Purchaser, the manufacture shall
manufacture a Prototype Model as per the Approved Drawing and offer the same for
inspection. The Inspection of the Prototype Model shall be carried out as per the Format
prescribed at Clause 41, Section-IV of our Tender Specification. The Supplier shall offer
the core, windings and tanks of each transformer for inspection by the Purchaser‟s
representative(s). During stage inspection of the Prototype Model, all the measurements
like diameter, window, height, leg centre, stack width, stack thickness, thickness of
laminations etc for core assembly, conductor size, insulation thickness, I.D., O.D.,
Winding height, major and minor insulations for both HV and LV windings, length,
breadth, height and thickness of plates of transformer tanks, the quality of fittings and
accessories will be taken/ determined.
The Inspection Report for the Tests conducted by our Authorized Inspectors in
presence of the manufacturer‟s representative, for the Prototype Model offered for
inspection with suggested modifications, if any shall be submitted to the undersigned for
approval.
After Inspection, the Prototype Model shall be kept sealed, in the premises of the
manufacturer till the completion of delivery of final consignment, for future reference
during subsequent Inspections.
The Supplier can offer for final inspection of the transformers subject to clearance of the
stage inspection report by the Purchaser.
34.2 The equipment shall successfully pass all the type tests and routine tests mentioned in the
above Clauses and those listed in the most recent edition of the standards given in Clause
2, of this specification.
34.3 The Purchaser reserves the right to reject an item of equipment if the test results do not
comply with the values specified or with the data given in the technical data schedule.
34.4 Routine tests shall be carried out by the Supplier at no extra charge at their works.
Adequate facility with calibrated testing equipment must be provided by the
manufacturer free of cost to carry out the tests. Type test certificates must be furnished
along with the tender for reference of the Purchaser.
34.5 The Purchaser will witness all required tests. In order to facilitate this, the Supplier shall
give the Purchaser a minimum of two weeks notice as mentioned in clause-7(ii) of
General Terms and Condition of Contract (GTCC) that the materials are ready for
testing. If the Purchaser does not indicate his intention to participate in the testing, the
manufacturer may proceed with the tests only after receipt of written confirmation to this
effect from the Purchaser and shall furnish the results thereof to the Purchaser
consequent upon such testing.
34.6 Full details of the proposed methods of testing, including connection diagrams, shall be
submitted to the Purchaser by the Supplier for approval, at least one month before
testing.
All costs in connection with the testing, including any necessary re-testing, shall be
borne by the Supplier who shall provide the Purchaser with all the test facilities which
the latter may require, free of charge. The Purchaser shall have the right to select the
samples for test and shall also have the right to assure that the testing apparatus is duly
calibrated and correct. Measuring apparatus for routine tests shall be calibrated at the
expense of the Supplier at an approved laboratory and shall be approved by the
Purchaser.
34.7 The supplier shall submit to the Purchaser five signed copies of the test certificates,
giving the results of the tests as required. No materials shall be dispatched until the test
certificates have been received by the Purchaser and the Supplier has been informed that
they are acceptable.
The test certificates must show the actual values obtained from the tests, in the units used
in this specification, and not merely confirm that the requirements have been met.
In the case of components for which specific type tests or routine tests are not given in
this specification or in the quoted standards in Clause 2, of this specification, The
Supplier shall include a list of the tests normally required for these components. All
materials used in the Contract shall withstand and shall be certified to have satisfactorily
passed such tests.
34.8 The Purchaser at his discretion may re-confirm the Routine Test Results, particularly no
load losses, load losses and percentage impedance in his own laboratory or laboratory of
his choice.
No inspection or lack of inspection or passing by the Purchaser‟s Representative of
equipment or materials whether supplied by the Supplier or sub-supplier, shall relieve the
Supplier from his liability to complete the contract works in accordance with the contract
or exonerate him from any of his guarantees.
However in case of future discrepancy, if any, after acceptance of equipments,
observed at any stage during guarantee period, the matter may be referred to
Bureau of Energy Efficiency (B.E.E) for random testing of equipments supplied. In
such cases the observation of B.E.E shall be binding to both parties.
d) GUARANTEE
The supplier shall guarantee the following:
Quality and strength of materials used;
Satisfactory operation during the guarantee period of two years (24 months) from the
date of commissioning, or 30 months from the date of acceptance of the equipment
by the Purchaser following delivery, whichever is earlier;
Performance figures as supplied by the tendered in the schedule of guaranteed particulars; The offered surface treatment shall protect the treated metal from corrosion for a
period of not less than five years from the date of delivery. e) PACKING AND SHIPPING i) Packing
The equipment and any supporting structures are to be transported adequately sealed
against water ingress. All accessories and spares shall be packed and securely clamped
against movement in robust, wooden, non returnable packing cases to ensure safe transit
in rough terrain, cross country road conditions and in heavy rains from the
manufacturer‟s works to the work sites/ earmarked destinations.
11.9 All accessories shall be carefully packed so that they are fully protected during transport
and handling operations and in storage. Internal surfaces of loose accessories shall be
sealed by means of gaskets and blanking off plates. All parts liable to rust shall receive
an anti-rusting coat and shall be suitably protected. It shall be the responsibility of the
Supplier to make good any damage caused through insufficient packing.
Each packing case shall be indelibly marked, on two adjacent sides and on the top, with
the following:
Individual serial number; Purchaser‟s name; Contract number; Destination; A colour coded marking to indicate destination; Supplier‟s name; Name and address of supplier‟s agent in Orissa; Description and numbers of contents; Manufacturer‟s name; Country of origin; Case measurements; Gross and net weight in kilograms: and All necessary slinging and stacking instructions.
g) Each crate or container shall be marked clearly on the outside of the case to show TOP
and BOTTOM positions with appropriate signs to indicate where the mass is bearing and
the correct positions for slings. All component parts which are separately transported
shall have permanent identification marks to facilitate correct matching and assembly at
site. Welded parts shall be marked before welding. Six copies of each packing list shall
be sent to the Purchaser prior to dispatching the equipment.
11.10 Transportation
The Supplier shall be responsible for the transport of all plant and equipment supplied by
them and for the transport of all goods to the various specified destinations including all
road clearance, offloading, warehousing and insurance.
The Supplier shall inform himself fully as to all relevant transport facilities and
requirements and loading gauges and ensure that the equipment as packed for transport
conform to these limitations. The Supplier shall also be responsible for verifying the
access facilities specified.
The Supplier shall be responsible for the transportation of all loads associated with the
contract works and shall take all reasonable steps to prevent any highways or bridges
from being damaged by his traffic and shall select routes, choose and use vehicles and
restrict and distribute loads so that the risk of damage shall be avoided. The Supplier
shall immediately report to the Purchaser any claims made against the Supplier arising
out of alleged damage to a highway or bridge.
All transport accessories, such as riding lugs, jacking pads or blanking off plates shall
become the property of the Purchaser.
All items of equipment shall be securely clamped against movement to ensure safe
transit from the manufacturer‟s facilities to the specified destinations.
The Supplier shall advice the storage requirements for any plant and equipment that may
be delivered to the Purchaser‟s stores. The Supplier shall be required to accept
responsibility for the advice given in so far as these arrangements may have a bearing on
the behavior of the equipment in subsequent service.
12.1 Hazardous substances
The Supplier shall submit safety data sheets for all hazardous substances used with the
equipment. The Supplier shall give an assurance that there are no other substances
classified as hazardous in the equipment supplied. No oil shall be supplied or used at any
stage of manufacture or test without a certificate acceptable to the Purchaser that it has a
PCB content of less than 2 mg/ kg. The Supplier shall accept responsibility for the
disposal of such hazardous substances, should any be found.
The Supplier shall also be responsible for any injuries resulting from hazardous
substances due to non compliance with these requirements.
12.2 SUBMITTALS
13.1 Submittals required with the bid
The following shall be required with each copy of the bid :
o Completed technical data schedule;
o Descriptive literature giving full technical details of equipment offered;
14.2 Outline dimensions drawing for each major component, general arrangement drawing showing component layout and general schematic diagram;
14.3 Type test certificates ( short circuit withstand test and impulse test ) of the offered transformers conducted at CPRI/ or any NABL Accredited laboratory without which tender will be out rightly rejected.
56
1. Sample routine test reports;
Detailed reference list of customers already using equipment offered along with
performance certificates of such equipment, during the last 3 (three) years with
particular emphasis on units of similar design and rating;
1.1 Details of manufacturer‟s quality assurance standards and programme and
ISO
9000 series or equivalent national certification;
1.3 Deviations from this specification. Only deviations approved in writing before award of contract shall be accepted;
List of recommended spare parts and consumable items for five year of operation with prices and spare parts catalogue with price list for future requirements.
38.2 Submittals required after contract award
38.2.1 Programme
Five copies of the programme for production and testing
38.2.2 Technical Particulars
Within 30 days of contract award five bound folders with records of the technical
particulars relating to the equipment. Each folder shall contain the following information:
General description of the equipment and all components, including brochures;
Technical data schedule, with approved revision;
Calculations to substantiate choice of electrical, structural, mechanical component
size/ ratings;
Detailed dimension drawing for all components, general arrangement drawing
showing detailed component layout and detailed schematic and wiring drawings for
all components; along with core-coil assembly drawings, showing details of core
such as grade, thickness, window height, leg centre, diameter, step width, step
thickness and details of windings such as I.D., O.D , thickness , Conductor size, No.
of turns, major and minor insulations, winding height etc.
Detailed loading drawing to enable the Purchaser to design and construct foundations
for the transformer;
Statement drawing attention to all exposed points in the equipment at which copper /
aluminum or aluminum alloy parts are in contact with or in close proximity to other
metals and stating clearly what protection is employed to prevent corrosion at each
point;
Detailed installation and commissioning instructions;
At the final hold point for Purchaser approval prior to delivery of the equipment the
following shall be submitted ;
Inspection and test reports carried out in the manufacturer‟s works;
Operation and maintenance instructions as well as trouble shooting charts. 38.2.3 Operation and Maintenance Instructions
A copy of installation and commissioning instructions and of the operation and
maintenance instructions and trouble shooting charts shall be supplied with each
transformer.
38.3 Drawings 38.3.1 Within 15 days of award of contract, the Supplier shall submit 4 complete sets of
drawings as detailed below describing equipment in details. These drawings would be
duly approved by the Purchaser after due securitization and approval will be
communicated within 15 days of receipt of these drawings. After the drawings are
approved and communicated to the supplier, he would supply ten complete sets of final
drawings.
38.3.2 All detail drawings submitted for approval shall be to scale not less than 1:20. All
important dimensions shall be given and the material of which each part is to be
constructed shall be indicated on the drawings. All documents and drawings shall be
submitted in accordance with the provisions of this specification and shall become the
property of the Purchaser. % All drawings and calculations, submitted to the Purchaser, shall be on international
standard size paper, either A0, A1, A2, A3 or A4. All such drawings and calculations
shall be provided with a contract title block, which shall include the name of the
Purchaser and shall be assigned an unique project drawing number; the contract title
block and project numbering system shall be agreed with the Purchaser.
% Script sizes and thickness of scripts and lines be selected so that if reduced by two stages
the alphanumeric characters and lines are still perfectly legible so as to facilitate
microfilming.
% For presentation of design drawings and circuit documents IEC Publication 617 or
equivalent standards for graphical symbols are to be followed. The drawing approval will
be communicated within 15 days from the receipt of drawings from the Bidder and for
any delay in furnishing the drawings, if delivery period will be delayed, no extension of
delivery time will be granted due to this.
% The following drawings for each item are to be submitted as part of this Contract.
4.5 Out line dimensional drawings of transformers and accessories
4.6 Assembly drawings and weights of main component parts.
4.7 Transportation drawings showing dimensions and weights of each package.
4.8 Drawings giving the weights for foundations each .
4.9 Drawing showing details such as clamping arrangements of core, core assembly showing oil duct section of HT and LT coils with conductor size showing insulation arrangements of windings and their reinforcement to withstand short circuit stresses, in side tank dimensions showing core assembly. Details of core and windings, as enumerated at Cl. No. 33.2.2 of this part of Specification shall be indicated in the above drawings.
4.10 Schematic diagram showing the flow of oil in the cooling system as well as each limb and winding. Longitudinal and cross- sectional views showing the duct sizes, cooling pipe etc. for transformer/ heat exchanger, drawn to scale shall be furnished.
4.11 Large Scale drawings of high and low tension winding of the transformers showing the nature and arrangements of insulation and terminal connection.
19 Name plate drawing showing details as per Cl. 23 of Part-2 of Technical
Specification.
20 Test Reports
39 FASTENERS 39.1 All bolts, studs, screw threads, pipe threads, bolt heads and nuts shall comply with the
appropriate Indian Standards for metric threads, or the technical equivalent.
39.2 Bolts or studs shall not be less than 6 mm in diameter except when used for small wiring
terminals. All nuts and pins shall be adequately locked. 39.3 Wherever possible, bolts shall be fitted in such a manner that in the event of failure of
locking resulting in the nuts working loose and falling off, the bolt will remain in
position. 39.4 All ferrous bolts, nuts and washers placed in outdoor positions shall be of anti-corrosive
materials except high tensile steel bolts and spring washers which shall be electro-
galvanized to service condition stated elsewhere in the Specification. Appropriate
precautions shall be taken to prevent electrolytic action between dissimilar metals where
bolts are used on external horizontal surfaces and where water can collect, methods of
preventing the ingress of moisture to the threads shall be provided. Each bolt or stud
shall project at least one thread but not more than three threads through the nut, except
when otherwise approved for terminal board studs or relay stems. If bolts nuts are
placed so that they are inaccessible by means of ordinary spanners, special spanners
shall be provided. The length of the screwed portion of the bolts shall be such that no
screw thread may form part of a shear place between members. Taper washers shall be
provided where necessary. Protective washers of suitable material shall be provided
front and back on the securing screws.
40. LABELS
All apparatus shall be clearly labelled indicating, where necessary, its purpose and 40.1 service positions. The material of all labels and plates, their dimensions, legend and the
method of printing shall be subject to approval of the Purchaser. The surfaces of all
labels and plates shall have a mat or satin finish to avoid dazzle from reflected light.
Colours shall be permanent and free from fading. Labels mounted on black surfaces
shall have white lettering. Danger plates shall have white lettering on a red background.
All labels and plates for outdoor use shall be of in-corrodible material. Where the use of
enameled iron plates is approved, the whole surface including the back and edges, shall
be properly covered and resistant to corrosion. They shall be engraved in English. Name
plates shall be white with black engraved lettering and shall carry all the applicable
information specified in the applicable items of the Standards. No scratching,
corrections or changes will be allowed on name plates.
40.2 Name plates shall be provided of white background with black engraved lettering
carrying all the applicable information specified in the standards and other details as
required by the Purchaser. The name plate inscription and the size and lettering shall be
submitted to the Purchaser for approval.
41. PROFORMA FOR STAGE INSPECTION OF DISTRIBUTION TRANSFORMERS
(A) GENERAL INFORMATION:
1. Name of Firm :
2. Order No and Date :
3. Rating –wise quantity offered :
4. Details of offer
(a) Rating
(b) Quantity
(c) Serial Numbers
5. Details of last stage inspected lot :
(a) Total quantity inspected
(b) Serial Numbers
(c) Date of stage inspection
(d) Quantity offered for final inspection of
8. (A) Inspection of BEE 3 Star Level/ Embossing / Punching requirement: whether satisfies the Specification:
deviation if any to be mentioned: 6
(B) AVAILABILITY OF MATERIAL FOR OFFERED QUANTITY:
Details to be filled in
(C) POSITION OF MANUFACTURING STAGE OF THE OFFERED
QUANTITY :
(a) Complete tanked assembly
(b) Core and coil assembly ready 61
9. Core assembled
10. Coils ready for assembly
9.1 HV Coils
9.2 LV Coils
NOTE:
10 A quantity if more than 100 no‟s shall not be entertained for stage inspection
11 The stage inspection shall be carried out in case:-
10.1 At Least 25% quantity offered has been tanked and
10.2 Core coil assembly of further at least 30% of the quantity offered has been completed.
10.3 Quantity offered for stage inspection should be offered for final inspection within 15 days from the date of
issuance of clearance for stage inspection, otherwise stage inspection already cleared shall be liable for
cancellation.
Sl.No Particulars As Offered As observed Deviation and Remarks
D INSPECTION OF CORE 11. Core material
11.1
Manufacturer's Characteristic Certificate in respect of grade of lamination used. (Please furnish test certificate)
11.2 Remarks regarding Rusting and smoothness of core
11.3
Whether laminations used for top and bottom yoke are in one piece.
12. Core Construction: 1 No of steps 2 Dimension of Steps
Step No. 1 2 3 4 5 6 7 8 9 10 11 12
As Offered
W mm
T mm
As found
W mm
T mm
3 Core Dia (mm)
4 Total Cross Section area of
core
5 Effective cross Sectional
area of core
6 Clamping arrangement
(i) Channel Size
(ii) Bolt size and No (iii) Tie Rods (iv) Painting (a) Channels (b) Tie Rods ( c) Bolts 7 Whether top yoke is cut for
LV connection
8 If yes, at 7 above, whether Reinforcement is done
9 Size of support Channels provided for Core base and bottom yoke (Single Piece of channels are only acceptable)
10 Thickness of insulation
provided between core base and support channel
11 Core length (leg center to
leg centre) 12 Window height 13 Core height 14
Core weight only (without channel etc.)
(E) INSPECTION OF
WINDING (I)
Winding material
1 Material used for
(a) HV Winding
(b) LV Winding 2 Grade of material for
(a) HV Winding
(b) LV Winding
3 Test certificate of
manufacturer (enclosed copy) for winding material of :
(a) HV (b) LV CONSTRUCTIONAL
(II) DETAILS 1 Size of Cross Sectional
area of conductor for:
(a) HV Winding
(b) LV Winding 2 Type of insulation for
conductor
(a) HV Winding
(b) LV Winding Diameter of wire used for
17.3.8 delta formation (mm) 17.3.9 Diameter of coils
in: a LV Winding 17.3.10 Internal dia (mm) (ii) Outer dia (mm) 17.3.13 HV
Winding Internal
dia (mm)
Outer dia (mm) 17.3.15 Current Density
of winding material uised for HV LV
17.3.16 Whether neutral
formation on top 17.3.17 HV Coils/ Phase a) Number b) Turns/ coil c) Total turns 8 LV Coils/ Phase
a) Number b) Turns/coil c) Total turns 9 Method of HV Coil Joints
10 Total weight of coils of
(a) HV Winding (Kg)
(b) LV Winding (Kg) F INSULATION
MATERIALS: (I) MATERIAL 1 Craft paper
a) Make b) Thickness (mm) c) Test certificate of
manufacturer (enclosed copy)
2 Press Board
a) Make Thickness
(mm)
Test certificate of manufacturer (enclosed copy)
3 Material used for top and bottom yoke and insulation
II Type and thickness of material used: (mm)
a) Between core and LV b) Spacers c) Interlayer d) Between HV &
LV winding e) Between phases f) End insulation
G CLEARANCES 21 Related to core and
winding 22.1 LV to Core (Radial)
22.2 Between HV and
LV (Radial) 22.3 (i) Phase to phase
between HV Conductor
Whether two Nos Press Board each of minimum 1 mm ;thick provided to cover the tie rods
22.4 Thickness of locking spacers between LV coils
(mm) 5 Axial wedges between
HV and LV coils / phase (Nos)
6 No. of radial spacers per phase between HV coils
7 Size of duct between LV
and HV winding (mm) (II) Between core-coil
assembly and tank: (mm)
1 Between winding and body a) Tank lengthwise
b) Tank breadth wise
2 Clearance between top
cover and top yoke upto 100 KVA and between top cover and top most live part of tap changing switch for 200 KVA and above.
H TANK 1 Constructional details:
1) Rectangular shape
65
2) Thickness of side wall (mm)
3) Thickness of top and bottom place (mm)
4) Provision of slopping top cover towards HV bushing 5) Tank internal dimensions(mm) (a) Length
(b) Breadt
h ( c)
Height
(i) On LV side
On LV side (II) General Details
1) Inside painted by varnish/ oil corrosion resistant paint (please specify which type of coating done)
2) Gasket between top cover and tank (i) Material
(ii) Thickness(mm)
(iii) Joint over laps (mm)
3) Reinforcement of welded angle (Specify size and No. of angle povided) on side walls of tank 4) Provisionof lifting lugs:
a) Numbers
b) Whether lugs of 8 mm thick MS plate provided
c) Whether reinforced by welded plates edge wise below the lug up to re-enforcing angle of the tank done
5) Pulling lug of MS Plate
a) Nos
b) Thickness (mm).
c) Whether provided on breadth side or length side 6) Provision of air release plug
7) Provision of galvanized GI Nuts Bolts with 1 No Plain and 1 No spring washer
8) Deformation of length wise side wall of tank when subject to:
a) Vaccume of (-) 0.7 Kg/sq cm for 30 minutes
b) Pressure of 0.8 Kg/sq cm for 30 minutes
(I) RADIATORS
1. Fin radiators of 1.25 mm thick sheet
a) Dimension of each fin (L x B x T) b) Fins per radiators
c) Total No. of radiators
Verification of manufacturer’s test certificate regarding Heat dissipation (excluding Top and Bottom) in w/sq m
Verification of position of radiator with respect to bushing
(J) CONSERVATOR
1. Dimensions ( L x D) (in mm) 2. Volume (m3)
3.Inside dia of Conservator tank
4. Whether conservator outlet pipe is projected approx.20 mm inside the conservator tank
5Whether arrangement made so that oil does not fall on the active parts
6. Whether die cast metal oil level gauge indicator having three positions at ( -5˚ C, 30˚ C and 98 ˚ C is provided.
7. Whether drain plug and filling hole with cover is provided
8. Inner side of the conservator tank painted with.
(K) BREATHER
1.Whether Die cast Aluminum body breather for silica gel provided
2. Make
3. Capacity
67
34.1 TERMINALS 34.2 Material whether of Brass
Rods/ Tinned Copper HV
LV
34.3 Size (dia in mm)
HV
LV
34.4 Method of Star
connection formed on LV side of 6mm thick (Should use Al./ Cu. Flat bolted/ brazed with crimped lugs on winding alternatively for 63 and 100 KVA rating brazed is done covered with tubular sleeve duly crimped) Please state dimensions of Al/Cu flat or tubular sleeve used (mm)
34.5 Method of Connection of
LV of winding to LV bushing (end od winding should be crimped with lugs(Al/Cu) and bolted with bushing stud)
34.6 Method of Connection of
HV winding to HV bushing (Copper joint should be done by using silver brazing alloy and for Aluminum, brazing rod or with tubular connector crimped at three spots).
34.7 Whether SRB P tube/
insulated paper used for formation of Delta on HV
34.8 Whether Empire sleeves
used on the portion of HV winding joining to HV bushing
34.9 Whether neutral formation
is covered with cotton tape
(M) BUSHING 1 Whether HV bushing
mounted on side walls. 2 Whether sheet metal
pocket used for mounting bushing (pipe are not acceptable)
a) HV b) LV
68
3 Whether arrangement for studs for fitting of HV bushing are in diamond shape ( so that Arcing Horns are placed vertically) 4. Position of mounting of LV bushing
5. Bushing Clearance: (mm) a) LV to Earth
b) HV to Earth
c) Between LV Bushings
d) Between HV Bushings
(N) TANK BASE
CHANNEL/ROLLERS: 36.2 Size of channels(mm)
36.3 Whether channels
welded across the length of the tank
36.4 Size and type of roller
(mm) 37 OIL 38.1 Name of Supplier
38.2 Break down voltage of
oil:(KV)
i) Filled in tanked Transformers
In storage tank ( to be tested by Inspecting Officer).
Supplier's test certificate (Enclosed)
(P) ENGRAVING
/ PUNCHINGS 1. Engaraving of Sl. No and name of firm
i) On bottom of clamping channel of core-coil assembly
ii) On side wall and top cover of tank along with date of dispatch. / Guarantee Period iii) 3 Star Level: Whether contains 3 Star Level with style prescribed by the B.E.E.
o i) MS plate of size 125 x 125 mm welded on width side of stiffener
Following details engraved (as per approved GTP)
69
(a) Serial Number
(b) Name of Firm
( c) Order No. and Date
(d) Rating
(e) Name of Inspecting Officer (f) Designation
(g) Date of dispatch
( R) NAME PLATE DETAILS
Whether Name Plate is as per approved drawing
38.2.2 Colour of Transformer
Tank body with light blue colour
Conservator with
white colour 38.2.3 CHECKING OF
TESTING FACILITIES
(Calibration certificate also to be checked for its validity)
TESTS
No Load Current
No Load Loss
% Impedance
Load Losses
Insulation
Resistance Test
Vector Group Test (phase relationship)
Ratio and Polarity test
relationship
Transformer oil Test (Break down Voltage)
Magnetic Balance
Measurement of winding resistance (HV and LV both)
Induced over voltage
withstand test ( Double voltage and Double frequency)
Separate source
power frequency withstand test at 28 KV for HV and 3 KV for LV (one minute)
Air Pressure/ Oil leakage Test
70
14. Vacuum Test
15. Unbalanced current
test
16. Temperature
rise(Heat Run) test
(U) We have specifically
checked the following and
found the same as per
G.T.P./ deviations
observed as mentioned
against each.
i) Rustlessness of CRGO
laminations used
ii) Core Steps
iii) Core Area
iv) Core Weight
v) Winding cross section
area
a) LV
b) HV
vi) Weight of windings
vii) Clearance between
winding and wall of tank
(mm)
a) Length-wise
b) Breadth- wise
viii) Clearance between
top of yoke top most live
part of tap changer to
tank cover
ix) Details of Neutral
formation
x) Connections to
bushings
a) LV
b) HV
xi) Slope of tank top
xii) Position of mounting
of bushings
COMPANY INSPECTING OFFICER FIRMS
REPRESENTATIVE DATE OF INSPECTION
. 71
GUARANTEED TECHNICAL PARTICULARS FOR 25KVA,11/0.4KV, 3-PHASE STAR RATED DISTRIBUTION TRANSFORMERS
(To be furnished by the Manufacturer) Sl.
No Description As Specified Bidder's Offer 1 Make
2 Name of the Manufacturer
3 Place of Manufacture
3 (a) Type of B.E.E Specified Star Level to be fixed near
Name Plate. BIS ENERGY EFFICIENCY LEVEL-2 & BEE STAR-1
4 Voltage Ratio 11000/433V
5 Rating in KVA 25
6 Core Material used and Grade: CRGO and M3 or Better
a) Flux density 1.5 Tesla (Max.)
b) Over fluxing without saturation (Curve to be
furnished by the Manufacturer in support of his
claim)
7 Maximum temperature rise of:
400C over an ambient of
a) windings by resistance method 500C
350C over an ambient of
b) Oil by thermometer 500C
8 Magnetizing (no-load) current
at: a) 90% Voltage
b) 100% Voltage 3% (Max.)
c) 112.5% Voltage 6% (Max.) 9 Core loss in watts:
a) Normal voltage
b) Maximum voltage
(a) Resistance of windings at 200C (with 5%
tolerance) HV Winding (ohms)
LV Winding (ohms)
(b) Full load losses (watts) at 75
0C
12 Total losses at 100% load at 75 0 C 695 Watts (Max.)
13 Total losses at 50% load at 75 0 C 210 Watts (Max.)
14 Current density used for : (Ampere/ Sq mm)
a) HV Winding 1.6(Max.)
b) LV Winding 1.6(Max.)
15 Clearances : (mm)
a) Core and LV
b) LV and HV
c) HV Phase to Phase
78
d) End insulation clearance to earth
e) Any point of winding to tank
16 Efficiency at 75 0 C:
a) Unity P. F. and
b) 0.8 P.F
1) 125% load
2) 100% load
3) 75% load
4) 50% load
5) 25% load
17 Regulation at:
a) Unity P.F.
b) 0.8 P.F. at 750C
18 % Impedance at 750C
4.5+10%(No negative
tolerance)
19 Separate Source Voltage withstand Test:
(I) HV 28kV/50 HZ for 1 minute Yes
(ii) LV 3kV/50 HZ for 1 minute Yes
22KV for HV winding by
20 applying 0.866 KV on LV
Induced Over Voltage withstand Test (Double at 100Hz for the duration
Voltage and Double frequency for 1 minute) of 1 minute.
21 Impulse test HV-95KV peak, LV- NA
22 Mass of : (kg)
a) Core lamination (minimum)
b) Windings (minimum)
c) Tank and fittings
d) Oil
e) Oil quantity (minimum) (litre)
f) Total weight
23 Oil Data:
1. Quantity for first filling (minimum) (litre)
2. Grade of oil used
3. Maker's name
4. BDV at the time of filling (kV)
24 Transformer:
1) Overall length x breadth x height (mmx mmx
mm)
2) Tank length x breadth x height
3) Thickness of plates for
a) Side plate (min) 3.15mm
b) Top and bottom plate (min) 5mm
4) Conservator Dimensions.
25 Radiation
1) Heat dissipation by tank walls excluding top and
bottom
2) Heat dissipation by cooling tube.
3) Diameter and thickness of cooling tube.
4) Whether calculation sheet for selecting cooling
area to ensure that the transformer is capable of
giving continuous rated output without exceeding
temperature rise is enclosed.
26 Inter layer insulation provided in design for:
1) Top and bottom layer Epoxy Dotted Kraft Paper
2) In between all layer Epoxy Dotted Kraft Paper
3) Details of end insulation. Press Board
4) Whether wedges are provided at 50% turns of
the HV coil
27 Insulation materials provided
a) For conductors
(1) HV DPC
(2) LV DPC
b) For Core Carlite
28 Material and Size of the wire used.
1) HV Dia (mm) (SWG)
2) LV
a) Strip size
b) No. of Conductors in parallel
c) Total area of cross section (sq mm)
29 Whether the name plate gives all particulars as
required in Tender
Yes
30 Particulars of bushings HV/LV
1) Maker's name
2) Type IS-3347/ IS-2099/ IS- 7421
3) Rating as per IS
4) Dry power frequency voltage withstand test HV-28KV, LV-3KV
5) Wet power frequency voltage withstand test HV-28KV, LV-3KV
Note:
The following shall be specifically confirmed:
Whether the offer conforms to the limits of
1) impedance mentioned in the specification.
Whether the offer conforms to the limits of
2) temperature rise mentioned in the specification.
Whether the losses of the transformers offered are
3) within the limits specified.
Whether the transformer offered is already type
4) tested for the design and test reports enclosed.
GUARANTEED TECHNICAL PARTICULARS FOR 16 KVA,11/0.4KV, 3-PHASE STAR RATED DISTRIBUTION TRANSFORMERS
(To be furnished by the Manufacturer) Sl.
No Description As Specified Bidder's Offer 4 Make
5 Name of the Manufacturer
6 Place of Manufacture
3 (a) Type of B.E.E Specified Star Level to be fixed near
Name Plate. BIS ENERGY EFFICIENCY LEVEL-2 & BEE STAR-1
4 Voltage Ratio 11000/433V
5 Rating in KVA 16
6 Core Material used and Grade: CRGO and M3 or Better
a) Flux density 1.5 Tesla (Max.)
b) Over fluxing without saturation (Curve to be
furnished by the Manufacturer in support of his
claim)
7 Maximum temperature rise of:
400C over an ambient of
a) windings by resistance method 500C
350C over an ambient of
b) Oil by thermometer 500C
9 Magnetizing (no-load) current
at: a) 90% Voltage
b) 100% Voltage 3% (Max.)
c) 112.5% Voltage 6% (Max.) 10
Core loss in watts:
a) Normal voltage
b) Maximum voltage
(c) Resistance of windings at 200C (with 5%
tolerance) HV Winding (ohms)
LV Winding (ohms)
(d) Full load losses (watts) at 75
0C
12 Total losses at 100% load at 75 0 C 695 Watts (Max.)
13 Total losses at 50% load at 75 0 C 210 Watts (Max.)
14 Current density used for : (Ampere/ Sq mm)
a) HV Winding 1.6(Max.)
b) LV Winding 1.6(Max.)
16 Clearances : (mm)
a) Core and LV
b) LV and HV
c) HV Phase to Phase
78
d) End insulation clearance to earth
e) Any point of winding to tank
16 Efficiency at 75 0 C:
a) Unity P. F. and
b) 0.8 P.F
1) 125% load
2) 100% load
3) 75% load
4) 50% load
5) 25% load
17 Regulation at:
a) Unity P.F.
b) 0.8 P.F. at 750C
18 % Impedance at 750C
4.5+10%(No negative
tolerance)
19 Separate Source Voltage withstand Test:
(I) HV 28kV/50 HZ for 1 minute Yes
(ii) LV 3kV/50 HZ for 1 minute Yes
22KV for HV winding by
20 applying 0.866 KV on LV
Induced Over Voltage withstand Test (Double at 100Hz for the duration
Voltage and Double frequency for 1 minute) of 1 minute.
21 Impulse test HV-95KV peak, LV- NA
22 Mass of : (kg)
a) Core lamination (minimum)
b) Windings (minimum)
c) Tank and fittings
d) Oil
e) Oil quantity (minimum) (litre)
f) Total weight
23 Oil Data:
1. Quantity for first filling (minimum) (litre)
2. Grade of oil used
3. Maker's name
4. BDV at the time of filling (kV)
24 Transformer:
1) Overall length x breadth x height (mmx mmx
mm)
2) Tank length x breadth x height
3) Thickness of plates for
a) Side plate (min) 3.15mm
b) Top and bottom plate (min) 5mm
4) Conservator Dimensions.
25 Radiation
1) Heat dissipation by tank walls excluding top and
bottom
2) Heat dissipation by cooling tube.
3) Diameter and thickness of cooling tube.
4) Whether calculation sheet for selecting cooling
area to ensure that the transformer is capable of
giving continuous rated output without exceeding
temperature rise is enclosed.
26 Inter layer insulation provided in design for:
1) Top and bottom layer Epoxy Dotted Kraft Paper
2) In between all layer Epoxy Dotted Kraft Paper
3) Details of end insulation. Press Board
4) Whether wedges are provided at 50% turns of
the HV coil
27 Insulation materials provided
a) For conductors
(1) HV DPC
(2) LV DPC
b) For Core Carlite
28 Material and Size of the wire used.
1) HV Dia (mm) (SWG)
2) LV
a) Strip size
b) No. of Conductors in parallel
c) Total area of cross section (sq mm)
29 Whether the name plate gives all particulars as
required in Tender
Yes
30 Particulars of bushings HV/LV
1) Maker's name
2) Type IS-3347/ IS-2099/ IS- 7421
3) Rating as per IS
4) Dry power frequency voltage withstand test HV-28KV, LV-3KV
5) Wet power frequency voltage withstand test HV-28KV, LV-3KV
Note:
The following shall be specifically confirmed:
Whether the offer conforms to the limits of
1) impedance mentioned in the specification.
Whether the offer conforms to the limits of
2) temperature rise mentioned in the specification.
Whether the losses of the transformers offered are
3) within the limits specified.
Whether the transformer offered is already type
4) tested for the design and test reports enclosed.
GUARANTEED TECHNICAL PARTICULARS FOR 63KVA,11/0.4KV, 3-PHASE STAR RATED DISTRIBUTION TRANSFORMERS
(To be furnished by the Manufacturer) Sl.
No Description As Specified Bidder's Offer 7 Make
8 Name of the Manufacturer
9 Place of Manufacture
3 (a) Type of B.E.E Specified Star Level to be fixed near
Name Plate. BIS ENERGY EFFICIENCY LEVEL-2 & BEE STAR-1
4 Voltage Ratio 11000/433V
5 Rating in KVA 63
6 Core Material used and Grade: CRGO and M3 or Better
a) Flux density 1.5 Tesla (Max.)
b) Over fluxing without saturation (Curve to be
furnished by the Manufacturer in support of his
claim)
7 Maximum temperature rise of:
400C over an ambient of
a) windings by resistance method 500C
350C over an ambient of
b) Oil by thermometer 500C
10
Magnetizing (no-load) current at: a) 90% Voltage
b) 100% Voltage 3% (Max.)
c) 112.5% Voltage 6% (Max.) 11
Core loss in watts:
a) Normal voltage
b) Maximum voltage
(e) Resistance of windings at 200C (with 5%
tolerance) HV Winding (ohms)
LV Winding (ohms)
(f) Full load losses (watts) at 75
0C
12 Total losses at 100% load at 75 0 C 695 Watts (Max.)
13 Total losses at 50% load at 75 0 C 210 Watts (Max.)
14 Current density used for : (Ampere/ Sq mm)
a) HV Winding 1.6(Max.)
b) LV Winding 1.6(Max.)
17 Clearances : (mm)
a) Core and LV
b) LV and HV
c) HV Phase to Phase
78
d) End insulation clearance to earth
e) Any point of winding to tank
16 Efficiency at 75 0 C:
a) Unity P. F. and
b) 0.8 P.F
1) 125% load
2) 100% load
3) 75% load
4) 50% load
5) 25% load
17 Regulation at:
a) Unity P.F.
b) 0.8 P.F. at 750C
18 % Impedance at 750C
4.5+10%(No negative
tolerance)
19 Separate Source Voltage withstand Test:
(I) HV 28kV/50 HZ for 1 minute Yes
(ii) LV 3kV/50 HZ for 1 minute Yes
22KV for HV winding by
20 applying 0.866 KV on LV
Induced Over Voltage withstand Test (Double at 100Hz for the duration
Voltage and Double frequency for 1 minute) of 1 minute.
21 Impulse test HV-95KV peak, LV- NA
22 Mass of : (kg)
a) Core lamination (minimum)
b) Windings (minimum)
c) Tank and fittings
d) Oil
e) Oil quantity (minimum) (litre)
f) Total weight
23 Oil Data:
1. Quantity for first filling (minimum) (litre)
2. Grade of oil used
3. Maker's name
4. BDV at the time of filling (kV)
24 Transformer:
1) Overall length x breadth x height (mmx mmx
mm)
2) Tank length x breadth x height
3) Thickness of plates for
a) Side plate (min) 3.15mm
b) Top and bottom plate (min) 5mm
4) Conservator Dimensions.
25 Radiation
1) Heat dissipation by tank walls excluding top and
bottom
2) Heat dissipation by cooling tube.
3) Diameter and thickness of cooling tube.
4) Whether calculation sheet for selecting cooling
area to ensure that the transformer is capable of
giving continuous rated output without exceeding
temperature rise is enclosed.
26 Inter layer insulation provided in design for:
1) Top and bottom layer Epoxy Dotted Kraft Paper
2) In between all layer Epoxy Dotted Kraft Paper
3) Details of end insulation. Press Board
4) Whether wedges are provided at 50% turns of
the HV coil
27 Insulation materials provided
a) For conductors
(1) HV DPC
(2) LV DPC
b) For Core Carlite
28 Material and Size of the wire used.
1) HV Dia (mm) (SWG)
2) LV
a) Strip size
b) No. of Conductors in parallel
c) Total area of cross section (sq mm)
29 Whether the name plate gives all particulars as
required in Tender
Yes
30 Particulars of bushings HV/LV
1) Maker's name
2) Type IS-3347/ IS-2099/ IS- 7421
3) Rating as per IS
4) Dry power frequency voltage withstand test HV-28KV, LV-3KV
5) Wet power frequency voltage withstand test HV-28KV, LV-3KV
Note:
The following shall be specifically confirmed:
Whether the offer conforms to the limits of
1) impedance mentioned in the specification.
Whether the offer conforms to the limits of
2) temperature rise mentioned in the specification.
Whether the losses of the transformers offered are
3) within the limits specified.
Whether the transformer offered is already type
4) tested for the design and test reports enclosed.
GUARANTEED TECHNICAL PARTICULARS FOR 100KVA,11/0.4KV, 3-PHASE STAR RATED DISTRIBUTION TRANSFORMERS
(To be furnished by the Manufacturer) Sl.
No Description As Specified Bidder's Offer 10
Make
11 Name of the Manufacturer
12 Place of Manufacture
3 (a) Type of B.E.E Specified Star Level to be fixed near
Name Plate. BIS ENERGY EFFICIENCY LEVEL-2 & BEE STAR-1
4 Voltage Ratio 11000/433V
5 Rating in KVA 100
6 Core Material used and Grade: CRGO and M3 or Better
a) Flux density 1.5 Tesla (Max.)
b) Over fluxing without saturation (Curve to be
furnished by the Manufacturer in support of his
claim)
7 Maximum temperature rise of:
400C over an ambient of
a) windings by resistance method 500C
350C over an ambient of
b) Oil by thermometer 500C
11
Magnetizing (no-load) current at: a) 90% Voltage
b) 100% Voltage 3% (Max.)
c) 112.5% Voltage 6% (Max.) 12
Core loss in watts:
a) Normal voltage
b) Maximum voltage
(g) Resistance of windings at 200C (with 5%
tolerance) HV Winding (ohms)
LV Winding (ohms)
(h) Full load losses (watts) at 75
0C
12 Total losses at 100% load at 75 0 C 695 Watts (Max.)
13 Total losses at 50% load at 75 0 C 210 Watts (Max.)
14 Current density used for : (Ampere/ Sq mm)
a) HV Winding 1.6(Max.)
b) LV Winding 1.6(Max.)
18 Clearances : (mm)
a) Core and LV
b) LV and HV
c) HV Phase to Phase
78
d) End insulation clearance to earth
e) Any point of winding to tank
16 Efficiency at 75 0 C:
a) Unity P. F. and
b) 0.8 P.F
1) 125% load
2) 100% load
3) 75% load
4) 50% load
5) 25% load
17 Regulation at:
a) Unity P.F.
b) 0.8 P.F. at 750C
18 % Impedance at 750C
4.5+10%(No negative
tolerance)
19 Separate Source Voltage withstand Test:
(I) HV 28kV/50 HZ for 1 minute Yes
(ii) LV 3kV/50 HZ for 1 minute Yes
22KV for HV winding by
20 applying 0.866 KV on LV
Induced Over Voltage withstand Test (Double at 100Hz for the duration
Voltage and Double frequency for 1 minute) of 1 minute.
21 Impulse test HV-95KV peak, LV- NA
22 Mass of : (kg)
a) Core lamination (minimum)
b) Windings (minimum)
c) Tank and fittings
d) Oil
e) Oil quantity (minimum) (litre)
f) Total weight
23 Oil Data:
1. Quantity for first filling (minimum) (litre)
2. Grade of oil used
3. Maker's name
4. BDV at the time of filling (kV)
24 Transformer:
1) Overall length x breadth x height (mmx mmx
mm)
2) Tank length x breadth x height
3) Thickness of plates for
a) Side plate (min) 3.15mm
b) Top and bottom plate (min) 5mm
4) Conservator Dimensions.
25 Radiation
1) Heat dissipation by tank walls excluding top and
bottom
2) Heat dissipation by cooling tube.
3) Diameter and thickness of cooling tube.
4) Whether calculation sheet for selecting cooling
area to ensure that the transformer is capable of
giving continuous rated output without exceeding
temperature rise is enclosed.
26 Inter layer insulation provided in design for:
1) Top and bottom layer Epoxy Dotted Kraft Paper
2) In between all layer Epoxy Dotted Kraft Paper
3) Details of end insulation. Press Board
4) Whether wedges are provided at 50% turns of
the HV coil
27 Insulation materials provided
a) For conductors
(1) HV DPC
(2) LV DPC
b) For Core Carlite
28 Material and Size of the wire used.
1) HV Dia (mm) (SWG)
2) LV
a) Strip size
b) No. of Conductors in parallel
c) Total area of cross section (sq mm)
29 Whether the name plate gives all particulars as
required in Tender
Yes
30 Particulars of bushings HV/LV
1) Maker's name
2) Type IS-3347/ IS-2099/ IS- 7421
3) Rating as per IS
4) Dry power frequency voltage withstand test HV-28KV, LV-3KV
5) Wet power frequency voltage withstand test HV-28KV, LV-3KV
Note:
The following shall be specifically confirmed:
Whether the offer conforms to the limits of
1) impedance mentioned in the specification.
Whether the offer conforms to the limits of
2) temperature rise mentioned in the specification.
Whether the losses of the transformers offered are
3) within the limits specified.
Whether the transformer offered is already type
4) tested for the design and test reports enclosed.
14.0 FASTENERS: Bolts, Nuts & Washers
22. All bolts and nuts shall conform to IS-6639 – 1972. All bolts and nuts shall be
galvanized. All bolts and nuts shall have hexagonal heads, the heads being
truly concentric, and square with the shank, which must be perfectly straight.
b) Bolts upto M16 and having length upto ten times the diameter of the bolt
should be manufactured by cold forging and thread rolling process to obtain
good and reliable mechanical properties and effective dimensional control.
The shear strength of bolt for 5.6 grade should be 310 Mpa minimum as per
IS-12427. Bolts should be provided with washer face in accordance with IS-
1363 Part-I to ensure proper bearing.
c) Fully threaded bolts shall not be used. The length of the bolt shall be such
that the threaded portion shall not extend into the place of contact of the
component parts.
d) All bolts shall be threaded to take the full depth of the nuts and threaded
enough to permit the firm gripping of the component parts but not further. It
shall be ensured that the threaded portion of the bolt protrudes not less than 3
mm and not more than 8 mm when fully tightened. All nuts shall fit and be
tight to the point where shank of the bolt connects to the head.
e) Flat washers and spring washers shall be provided wherever necessary and
shall be of positive lock type. Spring washers shall be electro-galvanized. The
thickness of washers shall conform to IS-2016-1967.
f) The bidder shall furnish bolt schedules giving thickness of components
connected, the nut and the washer and the length of shank and the threaded
portion of the bolts and size of holes and any other special details of this
nature.
g) To obviate bending stress in bolt, it shall not connect aggregate thickness
more than three time its diameter.
h) Bolts at the joints shall be so staggered that nuts may be tightened with
spanners without fouling.
i) Fasteners of grade higher than 8.8 are not to be used and minimum grade for
bolts shall be 5.6.
GENERAL TECHNICAL SPECIFICATION OF MATERIALS
A. TECHNICAL SPECIFICATION FOR ALL ALUMINIUM ALLOY
CONDUCTOR (AAAC)
1. SCOPE
This specification covers design, Engineering, Manufacture, Testing, Inspection
before dispatch, forwarding, packing, transportation to sites, Insurance (both during
transit & storage ), storage, erection, supervision testing & commissioning of all
sizes of All Aluminium Alloy Conductors of the Aluminium – magnesium- silicon
type for use in the distribution overhead power lines of SOUTHCO ,Orissa.
The material offered shall have been successfully type testes and the design shall
have been satisfactory operation for a period not less than two years on the date of
bid opening. Compliance shall be demonstrated by submitting with the bid, (i)
authenticated copies of the type test reports and (ii) performance certificates from
the users.
The scope of supply includes the provision of type test, Rates of type tests shall be
given in the appropriate price schedule of the bidding document and will be
considered for evaluation. The Purchaser reserves the right to waive type tests as
indicated in the section on Quality Assurance, Inspection and Testing in the
specification.
The Aluminium Alloy Conductor shall conform in all respects to highest standards
of engineering, design, workmanship, this specification and the latest revisions of
relevant standards at the time of offer and the Purchaser shall have the power to
reject any work or materials, which, in his judgment, is not in full accordance
therewith.
STANDARDS
Except where modified by the specification, the Aluminium Alloy Conductor shall
be designed, manufactured and tested in accordance with latest editions of the
following standards.
IEC :1089 Round wire concentric lay overhead
electrical standard conductors
IS 398 Aluminium Alloy Stranded Conductors
IS 9997 Aluminium Alloy redraw rods for
electrical purposes
IEC 502 : 1994 Extruded solid dielectric insulated power
cables for rated voltages 1.0 KV up to 30
KV
IEC 104 Aluminium Magnesium Silicon alloy wire
for overhead line conductors
IS 1778 Reels and drums of bare conductor.
BS : 6485-1971 PVC covered conductors for overhead
power lines.
This list is not to be considered exhaustive and reference to a particular standard or
recommendation in this specification does not relieve the contractor of the necessity of
providing the goods complying with other relevant standards or recommendations.
3. GENERAL
The wires shall be of heat treated Aluminium, magnesium silicon alloy containing
approximately silcon-0.5 to 0.9 %. magnesium-0.6 % to 0.9%,Fe-0.5% (maximum) ,
Copper- 0.1% (max ), mn- 0.03% , Cr-0.03%, Zn-0.1%, B-0.06%, and having the
mechanical and electrical properties specified in the table and be smooth and free
from all imperfections, such as, spills, splits and scratches.
Neutral grease shall be applied between the layers of wires. The drop point
temperature of the grease shall not be less than 1200 ˚C.
3.1 Mechanical and Electrical Characteristics of Aluminium Alloy Wires used
in the Construction of Stranded Aluminium Alloy Conductors
Nominal
Diameter
Minimu
m
Diameter
Max.
Diameter
Cross
Sectional
Area
Mass Minimum Breaking
Load
Maximu
m
Resistan
ce at 200
C
Before
stranding
After
stranding
mm mm mm mm2 Kg/k
m
KN KN ohms/km
4.26 4.22 4.30 14.25 38.48 4.40 4.18 2.345
Maximum resistance values given in column 8 have been calculated from the
maximum values of the resistively as specified and the cross sectional area based on
the minimum diameter. The minimum breaking load is calculated on nominal diameter
at ultimate tensile strength of 0.309 KN / mm² for wire before stranding and 95% of the
ultimate tensile strength after stranding.
4. PHYSICAL CONSTANTS FOR ALUMINIUM ALLOY
WIRES
4.1 Resistively :
For the purpose of this specification, the standard value of resistively of Aluminium
alloy wire which shall be used for calculation is to be taken as 0.0325 ohm mm² /m
at 200 ˚C. the maximum value of resistively of any single wire shall not , however,
exceed 0.0328 ohm. mm²/m at 20˚ C.
4.2 Density :
At a temperature of 200 ˚C, the density of aluminium alloy wire is to be taken as
2700 kg/m3.
4.3 Temperature Coefficient of Linear Expansion :
The temperature coefficient of linear expansion of aluminium alloy wire is to be
taken as
(23 x10-6
) per ˚C .
4.4 Constant – Mass Temperature Coefficient
At a Temperature of 200 ˚C, the constant – mass temperature coefficient of
resistance of Aluminium alloy wires, measured between two potential points
rigidly fixed to the wire, is taken as 0.00360/˚C
5. STANDARD SIZES
5.1 Nominal Sizes of Wires
The Aluminium alloy wires for standard constructions covered by this specification
shall have the diameters as specified in the table and a tolerance of ±1% shall be
permitted on the nominal diameter.
5.2 Standard Conductors
The sizes, resistance and masses (excluding the mass of grease ) of stranded
Aluminium alloy conductors shall be as given in table.
Sl. No. Actual
Area
Strandin
g and
Wire
Dia
Approx.
Overall
Dia
Approx.
Mass
Calculated
Maximum
Resistance
at 200 C
Approx
Calculated
Breaking
Load
1 2 3 4 5 6 7
mm² mm mm Kg/Km Ohm/Km KN
1 100 7/4.26 12.78 272.86 0.3390 29.26
5.3.1 Increase in Length due to Stranding When straightened out, each wire in any particular layer of a stranded conductor,
except the central wire, is longer than the stranded conductor by an amount
depending on the lay ratio of that layer.
5.3.2 Resistance and Mass of Conductor
The resistance of any length of stranded conductor is the resistance of the same
length of any one wire multiplied by a constant as set out in the table below.
The mass of each wire in any particular layer of the stranded conductor, except the
central wire, will be greater than that of an equal length of straight wire by an
amount depending on the lay ratio of that layer. The total mass of any length of an
Aluminium stranded conductor is, therefore, obtained by multiplying the mass of an
equal length of straight wire by an appropriate constant as mentioned below. In
calculating the stranding constants as mentioned in the table below, the mean lay
ratio, that is the arithmetic mean of the relevant minimum and maximum values in
table for lay ratio has been assumed for each layer.
5.3.3 Calculated Breaking Load of Conductor
For a conductor containing not more than 37 wires, 95% of the sum of strength of
the individual wires calculated from the values of the minimum breaking load given
in this specification.
For a conductor containing more than 37 wires, 90% of the sum of the strengths of
the individual wire calculated from the values of the minimum breaking load given
in this specification.
5.3.4 Calculated Area and Maximum Resistance of Conductor
The actual area of a stranded conductor has been taken as the sum of the cross-
sectional areas of the individual wires of nominal diameter.
Maximum resistance values of stranded conductor have been calculated on the basis
of maximum resistivity and the cross-sectional area based on the minimum diameter
of wires.
5.4 Stranding Constants
Number of Wires in
Conductor
Stranding Constants
Mass Electrical Resistance
7 7.091 0.1447
6. JOINTS IN WIRES
6.1 Conductor containing seven wires
There shall be no joint in any wire of a stranded conductor containing seven wires,
except those made in the base rod or wire before final drawing.
6.2 Conductors containing more than seven wires
In stranded conductors containing more than seven wires, joints in individual wires
are permitted in any layer except the outermost layer ( in addition to those made in
the base rod or wire before final drawing ) but no two such joints shall be less than
15 m apart in the complete stranded conductor. Such joints shall be made by cold
pressure butt welding. They are not required to fulfill the mechanical requirements
for unjointed wires.
7. STRANDING
The wire used in the construction of a stranded conductor shall, before and after
stranding, satisfy all the relevant requirements of this standard.
The lay ratio of the different layers shall be within the limits given in the table for
lay ratio.
In all constructions, the successive layers shall have opposite directions of lay, the
outermost layer being righ-handed. The wires in each layer shall be evenly and
closely stranded.
In Aluminium alloy stranded conductors having multiple layers of wires, the lay
ratio of any layer shall not be greater than the lay ratio of the layer immediately
beneath it.
7.1 Lay Ratios for Aluminium Alloy Stranded
Conductors
Number of Wires in Conductor Lay Ratios
7 Min-10 Max-14
NOTE: For the purpose of calculation the mean lay ratio shall be taken as the
arithmetic mean of the relevant minimum and maximum values given in this table.
8. LENGTHS AND VARIATIONS IN LENGTHS :
Unless otherwise agreed between the Employer and the Contractor, stranded
aluminium alloy conductors shall be supplied in the manufacturer’s usual
production lengths to be indicated in the bid Schedule. The Employer reserves
the right to specify particular lengths of conductor such that certain drum
lengths will be shorter than others. There will in both cases be a permitted
variation of –0 + 5% in the length of any one conductor length.
9. TESTS
9.1 Type Tests
The following tests shall be carried out as per relevant ISS once on samples of
completed line conductor during each production run of up to 500 kms of the
conductor from each manufacturing facility.
9.1.1 Ultimate Tensile Strength Test
This test is intended to confirm not only the breaking strength of the finished
conductor but also that the conductor has been uniformly stranded.
A conductor sample of minimum 5 m length fitted with compression dead end clamps
at either end shall be mounted in a suitable tensile test machine. Circles perpendicular
to the axis of the conductor shall be marked at two places on its surface. Tension on
the conductor sample shall be increased at a steady rate upto 50% of the minimum
UTS specified and held for one minute. The circles drawn shall not be distorted due to
relative movement of the individual strands. Thereafter the load shall be increased at a
steady rate to the specified minimum UTS and held at that load for one minute. The
conductor sample shall not fail during this period. The applied load shall then be
increased until the failing load is reached and the value recorded.
9.1.2 D.C Resistance Test
On a conductor sample of minimum 5 m length two contact clamps shall be fitted
with a pre-determined bolt torque. The resistance between the clamps shall be
measured using a Kelvin double bridge by initially placing the clamps at zero
separation and subsequently one meter apart. The test shall be repeated at least five
times and the average value recorded. The value obtained shall be corrected to the
value at 200 C, which shall conform to the requirements of this specification.
9.2 Routine Tests
Measurement of Physical Dimensions :
The samples should meet the desired dimensional requirements before conducting
following Routine Tests as per relevant ISS.
9.2.1 Selection of Test Samples
Samples for the tests specified in this specification shall be taken by the manufacturer
before stranding, from not less than 10% of the individual lengths of aluminium alloy
wire included in any one final heat-treatment batch and which will be included in any
one consignment of the stranded conductors to be supplied.
Alternatively, if desired by SOUTHCO at the time of placing an order, that the tests
be made in the presence of his representative, samples of wire shall be taken from
length of stranded conductor.
Samples shall then be obtained by cutting 1.2 meters from the outer end of the
finished conductor from not more than 10% of the finished reels or drums.
Tests for electrical and mechanical properties of Aluminium alloy wire shall
ordinarily be made before stranding since wires unlaid from conductors may have
different physical properties from those of the wire prior to stranding because of the
deformation brought about by stranding and by straightening for test.
Spools offered for inspection shall be divided into equal lots, the number of lots being
equal to the number of samples to be selected, a fraction of a lot being counted as s
complete lot. One sample spool shall be selected at random from each lot.
The following test shall be carried out once on samples of completed line conductor
during each production run of up to 500 kms of the conductor from each
manufacturing facility.
9.2.2 Breaking Load Test
The breaking load of one specimen, cut from each of the samples taken shall be
determined by means of a suitable tensile testing machine. The load shall be applied
gradually and the rate of separation of the jaws of the testing machine shall be not less
than 25 mm / min and not greater than 100mm /min.
9.2.3 Elongation Test
The elongation of one specimen cut from each of the samples taken shall be
determined as follows:
The specimen shall be straightened by hand and an original gauge length of 200 mm
shall be marked on the wire. A tensile load shall be applied as described above and
the elongation shall be measured after the fractured ends have been fitted together. If
the fracture occurs outside the gauge marks, or within 25 mm of either mark, and the
required elongation is not obtained, the test shall be disregarded and another test
should be made.
When tested before and after stranding, the elongation shall not be less than 4% on a
gauge length of 200 mm.
9.2.4 D.C Resistance Test
The electrical resistance test of one specimen cut from each of the samples taken shall
be measured at ambient temperature. The measured resistance shall be corrected to
the value at 20 ˚C by means of the formula :
R20 = RT [1/{1+α (T-20)}]
where ,
R20 = resistance corrected at 20˚ C
RT = resistance measured T˚ C
α= constant – mass temperature coefficient of resistance, 0.0036,
and T = ambient temperature during measurement.
The resistance corrected at 20 ˚ C shall not be more than the maximum values
specified.
9.2.5 Chemical Analysis of Aluminium Alloy
Samples taken from the alloy coils / strands shall be chemically / spectrographically
analyzed. The results shall conform to the requirements stated in this specification.
The contractor shall make available material analyses, control documents and
certificates from each batch as and when required by the Purchaser.
Test should be conducted at the independent test house by the purchaser in the case of
absence Of facility at manufacturer. However the cost of such testing shall be borne
by the manufacturer.
9.2.6 Dimensional and Lay Length Check
The individual strands of the conductors shall be dimensionally checked and the lay
lengths checked to ensure that they conform to the requirements of this specification.
Ten percent drums from each lot shall be rewound in the presence of the Purchaser or
his representative to allow visual checking of the conductor for joints, scratches or
other surface imperfections and to ensure that the conductor generally conforms to the
requirements this specification. The length of conductor wound on the drum shall be
re-measured by means of an approved counter / meter during the rewinding process.
9.2.7 Visual and dimensional Checks on the Conductor Drums.
The drums shall be visually and dimensionally checked to ensure that they conform to
the requirements of this specification and of IS 1778: Specification for reels and
drums of bare conductors. For wooden drums, a suitable barrel batten strength test
procedure is required. The Bidder shall state in his bid the tests to be carried out on
the drums and shall include those tests in the Quality Assurance Programme.
9.2.8 Acceptance Tests : All tests required to confirm enclosed Guaranteed Technical
Particulars (GTP) requirements of this specification needs to be conducted as
Acceptance Tests.
10. REJECTION AND RETESTS
10.1 Type Tests
Should the conductor fail any of the type tests specified above, the Purchaser will not
accept any conductor manufactured from the material, nor conductor made by the
manufacturing methods used for the conductor which failed the test.
The manufacturer shall propose suitable modifications to his materials and techniques
in order that he can produce conductor which will satisfactorily pass the type test
requirements.
10.2 Routine Tests
.
Should any one of the test pieces first selected fail the requirements of the tests, two
further samples from the same batch shall be selected for testings, one of which shall
be from the length from which the original test sample was taken unless that length
has been withdrawn by the manufacturer.
Should the test pieces from both these additional samples satisfy the requirements of
the tests, the batch represented by these samples shall be deemed to comply with the
standard. Should the test pieces from either of the two additional samples fail, the
batch represented shall be deemed not to comply with the standard.
If checks on individual strand diameters, conductor lay lengths and conductor surface
condition indicate non-compliance with the requirements of the specification, the
particular drum will be rejected. Inspection will then be carried out on two further
drums within the same batch. If the conductor on either of the drums is non-
complaint, the complete batch will be rejected.
10.3 Delivery Extension due to Rejection of Conductor
The rejection of conductor due to its failure to pass either type or routine tests shall
not permit the Contractor to apply for any extension to the time period within which
he has contracted to complete the project.
Description Requirement Details
furnished by
the bidder 55 Sq.mm
1. Stranding and diameter of Aluminum
Alloy Strand
7/3.15 mm
2. Over all diameter of conductor in mm 9.45
3. Standard nominal Aluminium Alloy
area
in Sq.mm
55
4. Calculated Aluminium alloy area in
Sq.mm
54.55
5. Minimum ultimate tensile strength of
Aluminium Wire strand in Kg/mm2
31.57
Kgs./Sq.mm
6. Guaranteed ultimate tensile strength of
conductor in Kg/mm2
1634 Kgs
7. Minimum breaking load in Kg. For
a) AluminiumAlloy Strand
b)Aluminium Alloy Conductor
2.29 KN
16.03 KN
8. Maximum working tension of
conductor
70% of UTS
9. Weight in Kg. Per KM of Aluminium
Alloy conductor
149.20 Kgs
approx.
10. Resistance in Ohm per KM at 20 C 0.621 max.
11. a) Continuous maximum current
rating
of conductor in still air at 450C ambient
temperature (A)
b) Temperature rise for the above current
(deg.C)
173 Amps
300C
12. Modulus of Elasticity of Aluminium
Alloy conductor Kg/Sq.mm
0.6320X106
13. Co-efficient of linear expansion per
degree centigrade for
a) Aluminium Alloy Strand/0C
b) Alloy conductor/0C
23X10-6
23X10-6
14. Standard length of each piece in KM 1.70 and above
15. Dimension of the reel in Cms. 135X50X71
16. Gross weight of the reel including
weight of the conductor Kg.
Max. 1500
17. Standard according to which the
conductor will be manufactured and
tested
IS : 398 (Part-4)
– 1994
18. Other particulars
TECHNICAL SPECIFICATION OF G.I EARTH PIPE
1. SCOPE: The Specification provides for the manufacture, testing at manufacturer‟s
works before supply of G.I Earth Pipes.
2. STANDARDS: The G.I Earth Pipes shall confirm in all respects to the Indian Standard
IS-1239 (Part-I)/ 1990.
3. GENERAL REQUIREMENTS: The G.I Earth Pipes shall be 40mm bore and 3.25mm
wall thickness as per IS-1239 (Part-I), 1990 length 2.5 meters as per specification.
4. TESTS AND TEST CERTIFICATES: All the tests shall be carried out as per the
IS-1239 (Part-i), 1990.
5. MARKING: The G.I Earth Pipes shall be legibly and indelibly marked as mentioned.
a). Name of Trademark of the manufacture.
b). Month and Year of manufacture and
c). Country of manufacture.
Sl. No Description Parameters Expected Value
1 Makers Name
2. Standard to which the earthing pipe confirm REC Standard-J 2
3. Size of the pipe 40 mm nominal Bore as per
ISS(Medium
gauge)1239/Part-I/1979
4. Length of the pipe 2.5mtrs
5. Thickness of the pipe 3.25mm
6. Outer diameter of the pipe 48.8 mm maximum
47.9 mm minimum
7. Standard for processing of Galvanising and testing for
uniformity and mass of Zinc coating of the pipe
IS:2620/1985 IS:2629/1986
SI:6745/1972
8. G.I Clamp for earthing pipe 40mmX6mm
9. G.I Bolts Size 5/8”X1 &1/2”
(K). TECHNICAL SPECIFICATION OF ALUMINIUM BINDING WIRE:
1.0 SCOPE:
Scope covers manufacture, testing and supply of 3.53 mm dia Aluminium Binding Wire as per IS
398.
2.0 MATERIALS:
The material comprising the wire shall have the following chemical composition: Aluminium 99.5%
minimum Copper, silicon and iron 0.5% maximum The surface of the wire shall be smooth and free
from all irregularities and imperfections. Its cross sections shall closely approximate that of true
circle.
Diameter of wire Cross sectional area
of nominal dia. Wires
(mm²)
Weight of
wire
kg/km
Breaking
Load
(kN) Minimum Nominal Maximum
3.15 3.53 3.55 9.787 26.45 1.57
Inspection and Tests
The following routine checks and tests shall be carried out on 10% of the coils of aluminium binding
wire. If anyone sample fails to pass any one of the test nominated for that wire, then samples shall be
taken from every coil in the consignment and any coil from which a sample proves defective shall be
rejected. On no account shall any rejected material be presented for test again unless with the written
approval of, and under conditions determined by the Purchaser.
Physical properties
The surface of the finished wires shall be checked to ensure that it is smooth , free from all
irregularities, imperfections and inclusions and that its cross section approximates closely that of true
circle. The wire shall be checked to ensure that its diameter and weight are within the values given in
the table above for characteristic of a aluminium binding wire.
Ultimate tensile strength
When tested on a standard tensile testing machine, the value obtained for the ultimate tensile stress
shall not be less than 1.57kN
Wrapping test
The wire shall withstand one cycle of a wrapping test as follows: The wire shall be closely wrapped
round a wire of its own diameter form a close helix of eight turns. Six turns shall then be unwrapped
and again closely rewrapped in the same direction as the first wrapping. The wire shall not break or
crack when subjected to this test.
Packing & Delivery
The aluminum binding wire shall be delivered in 30m coils, with a permitted tolerance of
+5%.Random or non standard lengths shall not be permitted. Each coil shall be adequately guarded
against damage due to transportation and handling and shall have an outer layer of tightly wound
polythene tape or be contained in a suitable, transparent plastic bag. The internal diameter of the
wound coil shall not be such as to result in a permanent set in the conductor.
The coils shall be contained in non returnable wooden cases, with a gross weight not in excess of 300
kg. The number of coils contained shall be marked on the outside of each case.
GUARANTEED TECHNICAL PARTICULARS
Sl.No. Description Bidder’s offer
1 Manufacturer Address
2 Indian Standard No. IS 398 (Part-4) 1994
3 Material of Binding Wire
4 Dia. Of Wire
5 Maximum D.C. resistance at 20 degree centigrade
6 Individual Aluminium Alloy Strands
A Tensile breaking stress
B Elongation on 200 mm length in breaking
7 Particulars of Raw Materials
7.1 Aluminium
a) Minimum Purity of aluminimum
7.2 Aluminium Alloy
a) Aluminium redraw rod conforming to element
(a) Si
(b) Cu
( c) Other Element (If any)
8 Linear mass of Wire
9 Modulus of Elasticity
10 Coefficent of Linear Expansion (per deg. Cent.)
DESIGN OF SPIKES
1. G.I. Plate 325 mm x 325 mm x 6 mm ( Wt. in Kg.= 5 kg.)
2. (i) Wt. of 2 No. plate =2 x 5 Kg =10 Kg.
(ii) Wt. of 40 mm x 4 mm thickness x 3 mtr length GI Pile= 85 Kg.
(iii) Wt of support pipe 50 mm x 4.5 mm x 100 mm = 5 Kg.
________
Total = 100 Kg
CONCRETING OF PSC POLES
N.B:- (1) After welding of channel and angles, the mass concreting has to be
done with minimum coverage of 75 mm.
(2) Concreting should be 1 : 2 : 4 (mix).
(3) Height of cooping above the ground should be 750 mm in cultivated land.
AB Cable Accessories
EYE HOOK DETAILS OF (AB Cable)
(One bolt in case of Dead End clamp & two bolts for fitting stay)
DEAD END BACK CLAMP
Suspension Back Clamp
Approx. wt.of 4.5 Kg.
Transformer Foundation for 250 KVA and above
ELEVATION
PLAN
DRAWINGS