111_CT-NCT spec-Dec, 2012

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HARYANA VIDYUT PRASARAN NIGAM LTD.

TECHNICAL SPECIFICATION

FOR

420kV CT, 245kV, 145kV, 72.5kV & 36kVCTs & NCTs & 12kV NCTs

SPECIFICATION No. HPD/S-77/HPM-465/Vol-II (DEC, 2012)

Chief Engineer/MMDesign Directorate,HVPNL, Shakti Bhawan,Sec-6, Panchkula-134109(Haryana)Tel./Fax No. -0172-2583724Email:- [email protected]

[email protected]

CONTENTS
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]

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CLAUSE NO. TITLE PAGE NO.1.0 SCOPE 32.0 STANDARDS 33.0 SERVICE CONDITIONS 44.0 PRINCIPAL PARAMETERS 45.0 GENERAL TECHNICAL REQUIREMENTS 66.0 TESTS 97.0 DOCUMENTATION 10

ANNEXURESI. COREWISE DETAILS FOR

A-(i) 420kV CT (2000-1000/1-1A, 2000-1000-500/1-1-1A) 12B-(i) 245kV TRANSFORMER CTs (450-300/0.577-1-1-1-1A) 12B-(ii) 245kV LINE CUM BUS COUPLER CTs (1200-800-400/1-1-1-1-1A) FOR 220KV S/STNS. 13B-(iii) 245kV B/C CT (2400-1200/1-1-1-1A) FOR 400KV S/STNS. 14B-(iv) 245kV T/F I/C CT (900-600-300/1-1-1-1-1A) 15B-(v) 245kV NCTs (450-300/1A) 15C-(i) 145kV T/F I/C CTs (750-500/0.577-1-1-1A) 16C-(ii) 145kV TRANSFORMER CTs WITH METERING CORE (250-150-100/0.577-1-1-1A) 16C-(iii) 145kV LINE CT AND 145kV B/C CTs for 132kV S/Stns. (600-300-150/1-1-1A) 17

C-(iv) 145kV NCTs (250-150-100/1A) 17C-(v) 145kV BUS COUPLER CT (750-500/1-1A) for 160MVA 220/132kV T/Fs 17D-(i) 72.5kV T/F I/C CTs (1500-1000/0.577-1-1-1A) 18D-(ii) 72.5kV T/F CTs (300-200-150/0.577-1-1A) FOR 66/11kV T/Fs 18D-(iii) 72.5kV LINE CT AND 72.5kV B/C CTs (600-300-150/1-1-1A) for 66kV S/Stns. 19D-(iv) 72.5kV TRANSFORMER INCOMER NCTs (1500-1000/1A) 19D-(v) 72.5kV NCTs (300-200-150/1A) FOR 66/11kV T/Fs 20D-(vi) 72.5kV BUS COUPLER CT (1500-1000/1-1A) for 160MVA 220/66kV T/Fs 20E-(i) 36 kV T/F I/C CTs FOR 132/33KV T/F WITH 26.3KA STC (1000-600-400/0.577-5-5-1A) 21E-(ii) 36kV T/F I/C CTs FOR 220/33KV T/F WITH 26.3KA STC (2000-1000/0.577-5-5-1A) 21E-(iii) 36kV LINE CUM CAPACITOR CTs WITH 26.3KA STC (400-300/5-1A) 22E-(iv) 36kV T/F I/C NCTs (1000-600-400/5A) FOR 132/33KV T/F WITH 26.3KA STC 22E-(v) 36kV T/F I/C NCTs (2000-1000/5A) FOR 220/33KV T/F ITH 26.3KA STC 22

E-(vi) 36kV Bus Coupler CTs (2000-1000/5A) FOR 220/33KV T/F WITH 26.3KA STC 23E-(vii) 36kV TRANSFORMER CTs(100-50/5-5A) FOR 4 MVA 33/11KV T/F WITH 26.3KA STC 23E-(viii) 36kV T/F NCT (100-50/5A) FOR 4 MVA 33/11KV T/F WITH 26.3KA STC 23F-(i) 12kV NCTs (1800-900/5A) FOR 25/31.5 MVA 24F-(ii) 12kV NCTs (1200-900/5A) FOR 12.5/16 MVA & 16/20 MVA 24F-(iii) 12kV NCTs (300-150/5A) FOR 4 MVA 33/11KV T/F 24

II. GUARANTEED TECHNICAL PARTICULARS 25

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1.0 SCOPE

1.1 This specification provides for design, engineering, manufacture, testing of out-doorinstrument transformers alongwith terminal connectors for protection and metering servicesin different 400/220/132/66kV S/Stns. in the state of Haryana.

1.2 It is not the intent to specify herein complete / all details of the design and construction of

equipment. However the equipment shall conform in all respects to high standards ofengineering design and workmanship and shall be acceptable to the purchaser, who willinterpret the meanings of drawings and specifications and shall have the power to reject anywork or material, which in his judgement is not in accordance therewith. The equipmentoffered shall be complete with all components necessary for its effective and trouble freeoperation. Such components shall deemed to be within the scope of supply irrespective ofwhether those are specifically brought out in this specification and or the commercial orderor not.

2.0 STANDARDS

Unless otherwise specified elsewhere in this specification the rating as well as performanceand testing of the instrument transformers shall conform but not limited to the latest

revisions and amendments available at the time of placement of order of all the relevantstandards as listed hereunder.

2.1 INSTRUMENT TRANSFORMERS :

Sr. No. Standard No. Title1. IS:2165 Insulation Co-ordination for equipment of 100kV and above.

2. IS:2705(I to IV)

Current Transformers.

3. IS:2099 Bushings for alternating voltages above 1000Volts.4. IS:3347 Dimensions of porcelain transformer bushings.

5. IS:2071 Method of High Voltage Testing.6. IS:335 Insulating oil for transformers Switchgears.

7. IS:2147 Degree of protection provided by enclosures for low voltageswitchgear and control.

8. IS:2633 Method of testing hot dipped galvanized articles.9. IS:4800 Enameled round winding wires.

10. IS:5561 Terminal connectors.11. IS:11065 Drawings.12. IEC 44-1 Current Transformers.

13. IEC-270(or IS:11322)

Partial Discharge Measurement

14. IEC-44(4) Instrument Transformer measurement of PDs.

15. IEC-171 Insulation co-ordination.16. IEC-60 High voltage testing techniques.17. IEC-8263 Method for RIV test on high voltage insulators.18. Indian Electricity Rules 1956.

19. IS:5621 Hollow porcelain insulators.

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2.2 Equipment meeting with the requirements of other authoritative standards, which ensureequal or better performance than the standards mentioned above, shall also be considered.When the equipment offered by the supplier conforms to other standards salient points ofdifference between standards adopted and the standards specified in this specification shallbe clearly brought out in the relevant schedule. Four copies of such standards withauthentic translation in English shall be furnished alongwith the offer.

3.0 SERVICE CONDITIONS:

3.1 Equipment to be supplied against this specification shall be suitable for satisfactorycontinuous operation under the following tropical conditions:-

1. Location IN THE STATE OF HARYANA2. Max. ambient air temp(OC) 50

3. Min. ambient air temp (0C) -2.54. Maximum Relative humidity (%) 1005. Minimum Relative humidity (%) 26

6. Average annual rainfall (mm) 9007. Max. wind pressure (Kg/sq.m.) 195

8. Max. altitude above mean sea level(meters) 1000

9. Isoceraunic level (days/year) 5010. Seismic level (horizontal

acceleration)0.3g

Note : Moderately hot and humid tropical climate conducive to rust and fungus growth. Theclimatic conditions are also prone to wide variations in ambient conditions. Smoke is alsopresent in the atmosphere. Heavy lightening also occurs during June to October.

4.0 PRINCIPAL PARAMETERS:

The current transformers covered in this specification shall meet the technical requirementslisted hereunder.

PRINCIPAL TECHNICAL PARAMETERS:

Sr.No.

Item 420kV 245kV 145kV 72.5kV 36kV 12kV

1. Type of C.T./installation.

single phase, dead tank, oilfilled, hermetically sealed,outdoor type.

Single phase, oil filled, Hermetically sealed, outdoor type

2. Type of Mounting Steel Structures

3. Suitable for systemFrequency

50 Hz

4. Highest systemVoltage (KV rms)

420 245 145 72.5 36 12

5. Minimum Neutral CTInsulating Voltage

- 33 15 15 15 8.66

6. Current Ratio A/Aa. Line CT 2000-1000-

500/1-1-1-1-11200-800-400/1-1-1-1-1

600-300-150/1-1-1

600-300-150/1-1-1

400-300/5-1 -

b. Transformer CT 2000-1000-500/1-1-1-1-1

450-300/0.577-1-1-1-1

250-150-100/0.577-1-1-1

300-200-150/0.577-1-1

100-50/5-5 -

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Sr.No.

Item 400kV 245kV 145kV 72.5kV 36kV 12

c. Transformer Incomer CT - 900-600-300/1-1-1-1-1

750- 500/0.577-1-1-1

1500-1000/0.577-1-1-1

2000-1000/0.577-5-5-1,1000-600-400/0.577-5-5-1

d. Capacitor CT - - - - 400-300/5-1A

e. NCT - 450-300/1 250-150-100/1 300-200-150/1, 1500-1000/1

2000-1000/5,1000-600-400/5,100-50/5

180900120900300150

f. Bus Coupler/Tie CT 2000-1000-500/1-1-1-1-1

2400-1200/1-1-1-1, 1200-800-400/1-1-1-1-1

750-500/1-1A,600-300-150/ 1-1-1

1500-1000/1-1A, 600-300-150/ 1-1-1

2000-1000/5

7. Method of Earthing theSystem

Solidly Earthed

8. Rated ContinuousThermal current

125% for all taps

9. Ratio taps The tapings shall be only on secondary winding.

10. Acceptable limit oftemperature rise abovethe specified ambienttemperature forcontinuous operation atrated current.

As per IS:2705 or equivalent IEC

11. Acceptance partialdischarge level at 1.1times the rated voltage.

As per IS:11322-1985 or equivalent IEC

12. 1.2/50 microsecond lightn ing impulse withstand voltage (kVp)

a. CTs 1425 1050 650 325 170

b. NCTs - 170 95 95 95

13. 1 minute dry & wet power frequency withstand Voltage primary (kV rms)

a. CTs 630 460 275 140 70

b. NCTs - 70 38 38 38

14. Power frequency overvoltage withstandrequirement forsecondary winding (kVrms) (for 1 minute)

3

15. Min. creepage distance of porcelain hous ing (mm)a. CTs 10500 6125 3625 1815 900

b. NCTs - 900 440 440 440 2

16. Rated short timewithstand current(kArms) for 1 Second.

40 40 31.5 31.5 26.3 1

17. Rated Dynamicwithstand current (kAp)

100 100 78.75 78.75 65.75

18. Maximum CreepageFactor

4.0

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5.0 GENERAL TECHNICAL REQUIREMENTS :

5.1 The insulation of the instrument transformer shall be so designed that the internal insulation shalhave higher electrical withstand capability than the external insulation. The designed dielectricswithstand values of external and internal insulation's shall be clearly brought out in the guaranteedtechnical particulars. The dielectric withstand values specified in this specification are meant for fullyassembled instrument transformers.

5.2 PORCELAIN HOUSING:

5.2.1. The details of location and type of joint, if provided on the porcelain, shall be furnished by theSupplier alongwith the offer. The housing shall be made of homogeneous, vitreous porcelain of highmechanical and dielectric strength, glazing of porcelain shall be uniform brown or dark brown colouwith a smooth surface arranged to shed away rain water or condensed water particles (fog).

5.2.2 Details of attachment of metallic flanges to the porcelain shall be brought out in the offer. Nuts andbolts or screws used for fixation of the interfacing porcelain bushings for taking out terminals shalbe provided on flanges cemented to the bushings and not on the porcelain.

5.3 METAL TANK:The metal tanks shall have bare minimum number of welded joints so as to minimize possiblelocations of oil leakage. The metal tanks shall be made out of mild steel/stainless steel/aluminum

alloy, depending on the requirement. Welding in horizontal plane is to be avoided as welding at thislocation may give way due to vibrations during transport resulting in oil leakage. Supplier has toobtain specific approval from purchaser for any horizontal welding used in the bottom tank. Thecastings of base, collar etc, shall be diecast and tested before assembly to detect cracks and voidsif any.

5.4 SURFACE FINISH :

The ferrous parts exposed to atmosphere shall be hot dip galvanized or shall be coated with atleastwo coats of Zinc Rich Epoxy painting. All nuts, Bolts and washers shall be of stainless steel.

5.5 INSULATING OIL:

Insulating oil required for first filling of the instrument transformer shall be covered in Supplier's

scope of supply. The oil shall meet the requirements of latest edition IS:335 or equivalent IEC.

5.6 PREVENTION OF OIL LEAKAGE & ENTRY OF MOISTURE:

5.6.1 The supplier shall ensure that the sealing of instrument transformer is properly achieved. In thisconnection the arrangement provided by the Supplier at various locations including the followingones shall be described, supported by sectional drawings.i) Locations of emergence of primary and secondary terminals.ii) Interface between porcelain housing and metal tank/s.iii) Cover of the secondary terminal box.

5.7 GASKETS:For gasketed joints, wherever used nitrile butyl rubber gaskets shall be used. The gasket shall befitted in properly machined groove with adequate space for accommodating the gasket under

compression.

5.8 OIL LEVEL INDICATORS:Instrument transformers shall be provided with oil sight window (Prismatic Type) at suitable locationso that the oil level is clearly visible with naked eye to an observer standing at ground level.

5.9 EARTHING:

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Metal tank of instrument transformer shall be provided with two separate earthing terminals forbolted connection to 50x8mm MS flat to be provided by the Purchaser for connection to station earthmat.

5.10 LIFITING AND TRANSPORTATION ARRANGEMENTS:Instrument transformer shall be provided with suitable lifting arrangement to lift the entire unit. Thelifting arrangement shall be clearly shown in the general arrangement drawing. Lifting arrangemen(lifting eye) shall be positioned in such a way as to avoid any damage to the porcelain housing orthe tanks during lifting for installation/transport. Necessary string guides, if required shall be offeredwhich shall be removable type. The CT/NCT shall be so constructed that it can be easily transportedto site within the allowable transport limitation and in horizontal position, if the transport limitationsso demand.

5.11 NAME PLATE:The instrument transformer shall be provided with non-corrosive, legible name plate with theinformation specified in relevant standards, duly engraved/punched on it. In addition to these thefollowing specific points shall also be marked on the name plate.

i) P.O. No. with date and (item No, if any)ii) Connection diagram.iii) Rated continuous thermal current.

iv) General knee point voltage formula.The size of nameplate and its location on the equipment should be such that it is clearly readablewith naked eyes while standing on ground.

5.12 TERMINAL CONNECTORS:5.12.1 Suitable terminal connectors of type 4 IPS Aluminium tube for 400kV CTs (Rigid type for one side

and expansion type for other side) and suitable terminal connectors for connecting twin tarantullafor 220kV T/F I/C CTs, 220kV B/C CT (2400-1200/1-1-1-1A), 33kV B/C CTs, 33kV T/F I/C CT(2000-1000/0.577-5-5-1A), 33kV T/F I/C NCT (2000-1000/5A), 132kV B/C CT(750-500/1-1A), 66kVB/C CT(1500-1000/1-1A), 66kV T/F I/C CT, 66kV T/F I/C NCT & single Tarantulla conductor for220kV T/F, Line/B.C CTs, 220kV NCTs, 132kV T/F I/C CT, 33kV Line cum Capacitor CT (400-300/5-1A) meant for 220/33kV T/F, twin ACSR Zebra for 33kV T/F I/C CT (1000-600-400/0.577-55-1A), 33kV T/F I/C NCT (1000-600-400/5A) meant for 40/50MVA 132/33kV T/F & for Single ACSR

Zebra for remaining CTs/NCTs shall be supplied. Suitable terminal earth connectors for earthingconnections shall also be provided.

5.12.2. The terminal connectors shall meet the following requirements:1) Terminal connectors shall be manufactured and tested as per IS:5561 or equivalent IEC.2) All castings shall be free from blowholes, surface blisters, cracks and cavities. All sharp edges and

corners shall be blurred and rounded off.3) No part of a clamp shall be less than 10mm thick.4) All ferrous parts shall be hot dip galvanized conforming to IS:2633 or equivalent IEC.5) For bimetallic connectors, copper alloy liner of minimum 2mm thickness shall be cast integral with

aluminium body.6) Flexible connectors shall be made from tinned copper/ aluminium sheets.7) All current carrying parts shall be designed and manufactured to have minimum contact resistance

8) Connectors shall be designed to be corona free in accordance with the requirements stipulated inIS:5561 or equivalent IEC.

5.13 INTERNAL INSULATION:Enamel, if used for conductor insulation, shall be polyvinyl acetate type and shall meet therequirements of IS:4800 or equivalent IEC. Polyester enamel shall not be used. Double cottoncover, if used, shall be suitably covered to ensure that it does not come in contact with oil.

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5.14 TEMPERATURE RISE:The temperature rise on any part of equipment shall not exceed maximum temperature risespecified in IS:2705 or equivalent IEC. However, the permissible temperature rise is for a maximumambient temperature of 50o C.

5.15 PRESSURE RELIEF DEVICE:Suitable arrangement shall be made for compensation of variation in the oil volume due to ambien

variation and to take care of internal abnormal pressures. The pressure variation shall be kept withinlimits, which do not impair the tightness of the instrument transformer. A pressure relief devicecapable of releasing abnormal internal pressure shall be provided.

5.16 SECONDARY TERMINAL BOXES:The CT secondary terminals except for 400kV CT (Annexure I-A(i)), 220kV Line CT(Annexure I B-(ii)), 145kV T/F CT (Annexure I C-(ii)), 145kV Line CT (Annexure I C-(iii)), 72.5kV Line CT (AnnexureI D-(iii)), 33kV T/F I/C CT (Annexure I E-(i)) & 33kV T/F I/C CT (Annexure I E-(ii)) shall be broughout in a weather proof terminal box. The terminal box shall be provided with removable gland plate

In case of 400kV CT, 220kV Line CT, 145kV Line CT, 72.5kV Line CT & 33 kV T/F I/C CTs, CTsecondary terminals shall be brought out in two separate weatherproof terminal boxes.

In the first box, the terminals of core Nos. 1,2, 4 & 5 (Ref. Annexure I A-(i)) of 400kV CT, Core Nos1,2,3 & 4 (Ref. Annexure I B-(ii)) of 220kV Line CTs, Core No. 1, 2 & 3 (Ref. Annexure I C-(ii)) of145kV T/F CT, Core Nos.1& 2 (Ref. Annexure I C-(iii)) of 145kV Line CT, Core Nos.1& 2 (Ref.

Annexure I D-(iii)) of 72.5kV Line CT & Core Nos.1, 2 & 3 (Ref. Annexure I E-(i) & E(ii)) of 33kV T/FI/C CTs shall be brought out. The terminal box shall be provided with removable gland plate.

The terminal of core No. 3 (Ref. Annexure I A-(i)) of 400kV CT, core No. 5 (Ref. Annexure I B-(ii)) of220kV Line CT, Core No. 4 (Ref. Annexure I C-(ii)) of 145kV T/F CT, Core No.3 (Ref. Annexure I C-(iii)) of 145kV Line CT, Core No.3 (Ref. Annexure I D-(iii)) of 72.5kV Line CT & Core No. 4 (Ref.

Annexure I-E(i) & (ii)) of 33kV T/F I/C CTs shall be brought out in the second terminal box. This shalalso be provided with a removable gland plate. This terminal box shall be provided with propersealing facility.

The terminal box/boxes shall be dust and vermin proof. The dimensions of the terminal box/boxesand its/their openings shall be adequate to enable easy access and working space with use ofnormal tools.

5.17 POLARITY :Polarity shall be indelibly marked on each primary and secondary terminal. Facility shall be providedfor short-circuiting and grounding of the secondary terminals inside the terminal box.

5.18 OIL FILLING AND DRAIN VALVES:The instrument transformers shall be vacuum filled with oil after processing and thereafterhermetically sealed to eliminate breathing and to prevent air and moisture from entering the tanksSealing type oil filling and/or oil sampling cocks shall be provided with facility to reseal the same.

The method adopted for hermetic sealing shall be described in the offer.5.19 INSTRUMENT SECURITY FACTOR:

The instrument security factor of metering core shall be low enough and less than 5. This shall bedemonstrated on all the ratios of the metering core, in accordance with procedure specified inIS:2705 or equivalent IEC. In case the instrument security factor of less than 5 is not possible to beachieved on higher ratios, auxiliary CTs of ratio 1/1 of relevant accuracy class shall be deemed to beincluded in the supplier's scope of supply. This shall also be specifically brought out by the supplier

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in his offer. However, the provision of auxiliary CT is not acceptable in case of 400kV CT(Annexure I A(i)), 220kV Line CT(Annexure I B-(ii)),145kV Line CT (Annexure I C-(iii)), 72.5kVLine CT (Annexure I D-(iii )) &33 kV T/F I/C CTs (Annexure I-E (i) & (ii)) as these CTs are to beused for commercial metering purpose.

5.20 PRIMARY WINDING:

The design density for short circuit current as well as conductivity of the metal used for primary

winding shall meet the requirement of IS:2705 or equivalent IEC. The supplier shall in his offerfurnish detailed calculations for selection of winding cross-sections.

5.21 SECONDARY WINDING:

Suitably insulated wire of electrolytic grade shall be used for secondary windings. Type of insulationused shall be described in the offer. For multi ratio design, suitable tapping shall be provided onsecondary winding only. Ratio tap selection through primary side shall not be acceptable.

5.22 CORE:The exciting current of the CT shall be as low as possible. The supplier shall furnish alongwith hisoffer the magnetization curve/s for all the core/s. The cores shall be of high grade, non-ageingelectrical silicon laminated steel of low hysterisis loss and high permeability to ensure high accuracyat both normal and over current.

5.23 PRIMARY TERMINALS:

For 400kV CT, 220kV Bus Coupler CT (2400-1200/1-1-1-1A), 66kV T/F I/C CT (1500-1000/0.577-1-1-1A), 66kV T/F I/C NCT (1500-1000/1A), 66kV B/C CT (1500-1000/1-1A), 33kV T/F I/C CT (2000-1000/0.577-5-5-1A & 1000-600-400/0.577-5-5-1A), 33kV T/F I/C NCT (2000-1000/5A & 1000-600-400/5A) & 33kV Bus Coupler CT the primary terminal shall be made out of rods of not less than40mm dia. copper or equivalent as per IS/IEC and for remaining CTs/NCTs the primary terminalsshall be made out of rods not less than 30mm dia. copper or equivalent as per ISS\IEC.

5.24 DEVIATION FROM SPECIFICATION:Any deviation from the specification shall be clearly brought out separately. In the absence of anyspecific mention, it shall be implied that the equipment offered is entirely according to thisspecification.

5.25 TEST TAP:The 72.5 kV and above voltage level, instrument transformers shall be provided with suitable testap for measurement of tests such as partial discharges etc. in factory as well as at site. Provisionshall be made of a screw on cap for solid and secured earthing of the test tap connection, when notin use. A suitable caution plate shall be provided duly fixed on the cover of the secondary terminabox indicating the purpose of the test tap and necessity of its solid earthing as per prescribedmethod before energising the equipment.

NOTE:- The Overall Tolerance for dimensions, Quantity of Oil , Weight, etc should be +5% max. TheGeneral Tolerance should be as per ISS. Tolerance for Mounting Dimension should be +5mm

6.0 TESTS:

6.1 TYPE TESTSThe equipment offered should be fully type tested. In case, the equipment of the type and designoffered has already been type tested, the supplier shall furnish 4 sets of type test reports alongwiththe offer. The type test reports should not be more than seven years old, reckoned from the date ofbid opening and the type test should have been carried out in accordance with ISS-2705(1992)/equivalent IEC from Govt./ Govt. approved test house.However, temperature rise test although covered under type tests will be got conducted by the

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supplier on one piece of total ordered quantity of each type, at his premises in the presence of theinspecting officer of the purchaser, without any extra charges. The purchaser reserves the right todemand repetition of some or all the type tests in the presence of purchaser's representative.

6.2 ACCEPTANCE AND ROUTINE TESTS:

i) All acceptance including Tan Delta test and routine tests as stipulated in the relevant standardsshall be carried out by the Supplier in presence of purchaser's representative, unless dispensed

with in writing by the Purchaser.ii) Immediately after finalisation of the programme of routine /acceptance testing, the Supplier shalgive sufficient advance intimation to the Purchaser to enable him to depute his representative fowitnessing the testing.

7.0 DOCUMENTATION:

7.1 All drawings shall conform to international standards organisation (ISO) `A' series of drawingsheet/Indian Standards Specification IS:11065. All drawings shall be in ink and suitable fomicrofilming. If drawings are computerized than all drawings shall be nicely printed. All dimensionsand data shall be in S.I.Units.

7.2 List of drawings:

a) General outline and assembly drawings of the equipment.b) Graphs showing the performance of equipment's in regard to magnetisation characteristics; ratio &

phase angle curves, ratio correction factor curves.c) Sectional views showing:i) General Constructional Features.ii) Materials/Gaskets/Sealing used.iii) The insulation & the winding arrangements, method of connection of the primary / secondary

winding to the primary/ secondary terminals etc.iv) No. of Turns, Cross-Sectional Area, Current density of Primary and secondary windings.v) Porcelain used and its dimensions.d) Arrangement of terminals and details of connection studs provided.e) Name plate.

f) Schematic drawing.g) Detailed drawing of pressure release device with detailed literature.h) Terminal connector drawing.

NOTE:- All above drawings should bear a minimum space (14X10cm) for stamping the approval o fdrawings by the purchaser.

7.3 The bidder shall submit four sets of final versions of complete and correct equipment drawingsexcept 7.2 (b) above (actual of which shall be supplied at the time of inspection) for purchasersapproval alongwith bid in a sealed envelope. The purchaser shall communicate hiscomments/approval on the drawings to the supplier within 21 days from the date of issue of LOIThe submission of complete and correct readable drawings for approval is the responsibility of the

bidder/supplier. The supplier shall, if so required by the purchaser, modify the drawings andresubmit four copies of the modified drawings for purchasers approval within two weeks from thedate of purchasers comments. Then, the purchaser shall approve the revised drawings within twoweeks from the date of its receipt.

7.4 The manufacturing of the equipment shall be strictly in accordance with the approved drawings andno deviation shall be permitted without the written approval of the purchaser. All manufacturing andfabrication work in connection with the equipment prior to the approval of the drawing shall be at the

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supplier's risk.

7.5 The successful bidder shall also supply one set of nicely bound all the approved drawings &instruction manual containing handling, installation, testing and commissioning of equipment at thetime of despatch of material to the consignee with each equipment for our field staffwithout whichthe supply will not be considered as complete supply. In addition, 5 sets of such bound

manuals and final approved drawings shall be supplied for reference & record in our design officealongwith one good quality soft copy (CD) of approved drawings and instruction manuals, ifcomputerized.

7.6 Approval of drawings / work by Purchaser shall not relieve the Supplier of his responsibility andliability for ensuring correctness and correct interpretation of the latest revision of applicablestandards, rules and codes of practices. The equipment shall conform in all respects to highstandards of engineering, design, workmanship and latest revisions of relevant standards at the timeof ordering and purchaser shall have the power to reject any work or material which in his

judgement is not in full accordance therewith.

NOTE :- In case the equipment offered by the Supplier does not meet with the requirement oftechnical specification the offer of the firm shall not be considered.

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ANNEXURE I-A(i)COREWISE DETAILS OF 420 kV CTs

(2000-1000-500/1-1-1-1-1A)

NUMBER OF CORES 5

CoreNo.

Appl ication Currentratio

Outputburden

(VA)

Accuracyclass

Min. kneePt. Voltage

Vk

Max. CT sec.wdg.

Resistance(ohms)

Max. Excitationcurrent at Vk

(in mA)

1 2 3 4 5 6 7 81 BUS DIFF

MAIN2000-1000 /1

- PS 2000/1000 10/5 30 on 2000/1 Tap; 60on 1000/1 Tap

2 BUS DIFFCHECK

2000-1000/1

- PS 2000/1000 10/5 30 on 2000/1 Tap; 60on 1000/1 Tap

3 METERING 2000-1000-500/1

20 0.2SISF

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ANNEXURE I-B(ii)

COREWISE DETAILS OF 245kV LINE CUM BUS-COUPLER CTs

(1200-800-400/1-1-1-1-1 A)

NUMBER OF CORES 5

CoreNo.

Appl ication CurrentRatio (A)

Outputburden(VA)

Accuracyclassas perIEC 185

Formula for minimumknee point voltage At CTSecondary resistance at750C at 800Atap (Volt)

MaximumExcitingCurrent(mA)

InstrumentSecurityfactor

1 2 3 4 5 6 7 81. MAINI

DISTANCEPROTECTION

1200-800-400/1

- PS 80(RCT+9) 80 @ Vk -

2. MAINIIDISTANCEPROTECTION

1200-800-400/1

- PS 80(RCT+9) 80 @ Vk -

3. BUS

DIFFERENTIALMAIN

1200-800-

400/1

- PS 100(RCT+4) 30 @ Vk/2 -

4. BUSDIFFERENTIALCHECK

1200-800-400/1

- PS 100(RCT+4) 30 @ Vk/2 -

5. METERING 1200-800-400/1

40 0.2S - - ISF

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ANNEXURE I-B(ii i)

COREWISE DETAILS OF 245 kV BUS COUPLER CTs FOR 400KV S/STNS.

(2400-1200/1-1-1-1A)

NUMBER OF CORES - 4

CoreNo.


Outputburden(VA)


Formula forminimum kneepoint voltage

At CTSecondaryresistance at750C at2400Atap (Volt)


ALF/ISF

1 2 3 4 5 6 7 8

1.O/C & E/FPROTECTION

2400-1200/1

25 5P - - 10

2. BUSDIFFERENTIAL

2400-1200/1

- PS 100(RCT+4) 30 @ Vk/2 -

3. BUSDIFFERENTIALCHECK

2400-1200/1

- PS 100(RCT+4) 30 @ Vk/2 -

4. METERING 2400-1200/1

40 1.0 - - ISF

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ANNEXURE I-B(iv)

COREWISE DETAILS OF 245 kV Transformer INCOMER CTs

(900-600-300/1-1-1-1-1A)

NUMBER OF CORES - 5

CoreNo.


Outputburden(VA)


Formula forminimumknee-pointvoltage

At CTSecondaryresistanceat 750C at900Atap(Volt)


I.S.F./A.L.F

1 2 3 4 5 6 7 8

1 DIFFERENTIAL

PROTECTION

900-600-300/1 - PS 40 (RCT+2) 30 @Vk/4 -

2 OVER CURRENT &EARTH FAULTPROTECTION

900-600-300/1 25 5P - - 10

3 METERING 900-600-300/1 25 1 - -

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ANNEXURE I-C(i)

COREWISE DETAILS OF 145kV TRANSFORMER INCOMER CT

(750-500/0.577-1-1-1A)

NUMBER OF CORES 4

CoreNo.


Outputburden(VA)

Accuracy Classas perIEC 185

Formula for minimumknee-point voltage At CTSecondary resis tance at750C at 500Atap (Volt)


I.S.F./A.L.F.

1 2 3 4 5 6 7 81. DIFFERENTIAL

PROTECTION750-500/

0.577- PS 40 (RCT+2) 30 @ Vk/4 -

2. REFPROTECTION

750-500/1 - PS 90 (RCT+2) 37.5 @ Vk/2 -

3. OVERCURRENT AND

EARTH FAULTPROTECTION

750-500/1 25 5P - - ALF10

4. METERING 750-500/1 25 1.0 - - ISF

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(600-300-150/1-1-1A)

No. OF CORES = 3CoreNo.


Outputburden(VA)

Accuracy classas perIEC 185

Formula for minimumknee-point voltage

At CT Secondaryresistance at 750C at

300Atap (Volt)


A.L.F./I.S.F.

1 2 3 4 5 6 7 81 DISTANCE

PROTECTION600-300-150/1 - PS 120 (RCT+4.5) 80 @ VKP -

2 OVER-CURRENT& EARTH FAULTPROTECTION

600-300-150/1 25 5P - - ALF 10

3 METERING 600-300-150/1 25 0.2S - - ISF

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ANNEXURE I-D(i)

COREWISE DETAILS OF 72.5kV TRANSFORMER INCOMER CT

(1500-1000/0.577-1-1-1A)

NUMBER OF CORES - 4

CoreNo.


Outputburden

(VA)

Accuracyclass

as perIEC 185

Formula for minimumknee-point voltage

At CT Secondaryresistance at 750C at1000A tap (Volt)


A.L.F./I.S.F.

1 2 3 4 5 6 7 81 DIFFERENTIAL

PROTECTION1500-1000/0.577 - PS 40 (RCT+2) 30 @ VK/4 -

2 REFPROTECTION

1500-1000/1 - PS 14 (RCT+2) 30 @ VK/2

3 OVERCURRENT &EARTH FAULTPROTECTION

1500-1000/1 15 5P - - ALF 10

4 METERING 1500-1000/1 15 1.0 - - ISF

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COREWISE DETAILS OF 72.5kV LINE CT AND 72.5kV BUS COUPLER CT for 66kV S/STNS.

(600-300-150/1-1-1A)

No. OF CORES = 3

CoreNo.


Outputburden(VA)


Formula for min kneepoint voltage At CTSecondary res. at 750Cat 300A tap (Volt)


A.L.F./I.S.F.

1 2 3 4 5 6 7 81 DISTANCE

PROTECTION600-300-150/1 - PS 80(RCT+4) 40 @VK/2 -

2 OVERCURRENT &EARTH FAULTPROTECTION

600-300-150/1 15 5P - - ALF 10

3 METERING 600-300-150/1 20 0.2S - - ISF

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COREWISE DETAILS OF 72.5 kV NEURAL CT FOR 66/11kV T/Fs

(300-200-150/1)

No. OF CORE = 1

CoreNo.


Outputburden(VA)

Accuracyclass asper IEC185

Formula forminimum kneepoint voltage atCT secondaryresistance at 750at 300A tap (Volt)

Maximumexcitingcurrent(mA)

MinimumInsulationvoltage(kV)

1 2 3 4 5 6 7 81. REF

PROTECTION300-200-150/1

- PS 20 (RCT+1) 30 @ Vk/2 15

ANNEXURE I-D(vi)

COREWISE DETAILS OF 72.5kV BUS COUPLER CT for 160MVA 220/66kV T/Fs.

(1500-1000/1-1A)

No. OF CORES = 2

CoreNo. Appl ication CurrentRatio (A) Outputburden(VA)

Accuracyclass as perIEC 185

A.L.F./I.S.F.

1 2 3 4 5 82 OVER-CURRENT & EARTH

FAULT PROTECTION1500-1000/1 15 5P ALF 10

3 METERING 1500-1000/1 20 1.0 ISF

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ANNEXURE I-E(i)

COREWISE DETAILS OF 36kV TRANSFORMER INCOMER CT FOR 40/50MVA 132/33kV T/F ANDOTHER RATINGS OF 132/33KV T/Fs WITH 26.3KA STC

(1000-600-400/0.577-5-5-1)No. OF CORES = 4

CoreNo.


Outputburden(VA)

Accuracyclass asPer IEC185

Formula forminimum kneepoint voltage At CTSecondaryresistance at 750Cat400A tap (Volt)

MaximumExcitingCurrent(ma)

A.L.F./I.S.F.

1 2 3 4 5 6 7 81 DIFFERENTIAL

PROTECTION1000-600-400/0.577 PS 40 (RCT+1) 30@VK/4

2 REFPROTECTION

1000-600-400/5 - PS 100(RCT+1) 75@VK/2

3 OVER CURRENT

& EARTH FAULTPROTECTION

1000-600-400/5 20 5P - - 10

4 MAINMETERING

1000-600-400/1 10 0.2S - -

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ANNEXURE I-E(ii i)COREWISE DETAILS OF 36kV LINE CUM CAPACITOR CT for 33kV LINE BAY AND FOR

20MVAR & 10MVAR CAPACITOR BANKS ON 220/33KV T/F & 40/50MVA 132/33kV T/F WITH26.3KA STC

(400-300/5-1)

No. OF CORES = 2

CoreNo.

Appl ication Current Ratio(A) (VA)

OutputBurden

AccuracyClass asper IEC185

A.L.F.

1. 2. 3. 4. 5. 6.1. OVER CURRENT & EARTH

FAULT PROTECTION400-300/5 20 5P 10

2. METERING 400-300/1 10 0.2S For ratio 300/1ISF

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COREWISE DETAILS OF 36kV BUS COUPLER CT FOR 220/33KV WITH 26.3KA STC(2000-1000/5A)

No. OF CORES = 1

CoreNo.


OutputBurden(VA)

Accuracy class as per IEC185

A.L.F.

1 2 3 4 5 61 OVER CURRENT

& EARTH FAULT

PROTECTION

2000-1000/5A

20 5P 10

ANNEXURE I-E(vii)

COREWISE DETAILS OF 36kV TRANSFORMER CT WITH 26.3KA STCFOR 4 MVA 33/11kV T/F

(100-50/5-5)

No. OF CORES = 2CoreNo.


Outputburden

(VA)

Accuracyclass asPer IEC185

Formula for minimumknee point vol tage

At CT Secondaryresistance at 750C at100A tap (Volt)


MinimumInsulationVoltage(kV)

1 2 3 4 5 6 7 81 REF

PROTECTION100-50/5 - PS 100 (RCT+1) 75@ VK/2 -

2 OVERCURRENTPROTECTION

100-50/5 20 5P - - 10

ANNEXURE I-E(vi ii )

COREWISE DETAILS OF 36kV TRANSFORMER NCT WITH 26.3KA STCFOR 4 MVA 33/11kV T/F

(100-50/5)

No. OF CORE = 1

CoreNo.


Accuracyclassas per

IEC 185

Formula for minimumknee-point voltage At CTSecondary resistance at

750

C at 100A tap (Volt)

MaximumExcitingCurrent

(mA)

MinimumInsulation Voltage

(kV)1 2 3 4 5 6 71 REF

PROTECTION100-50/5 PS 100 (RCT+1) 75@ VK/2 15

ANNEXURE-I F(i)

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COREWISE DETAILS OF 12 kV NEUTRAL CT FOR 25/31.5 MVA T/F

(1800-900/5)

No. OF CORE = 1

CoreNo.


Accuracyclass as

per IEC185

Formula for minimumknee point voltage at

CT secondaryresistance at 750 at1800A tap (Volt)

Maximumexciting

current(mA)

MinimumInsulation

voltage (kV)

1 2 3 4 5 6 71. REF

PROTECTION1800-900/5 PS 95 (RCT+1) 75@ Vk/2 8.66

ANNEXURE I-F(ii )

COREWISE DETAILS OF 12kV NEUTRAL CT FOR 12.5/16 MVA & 16/20 MVA T/F

(1200-900/5)

No. OF CORE = 1

CoreNo.



Formula for minimumknee-point voltage At CTSecondary resis tance at750C at 1200A tap (Volt)


MinimumInsulation Voltage(kV)

1 2 3 4 5 6 71 REF

PROTECTION1200-900/5 PS 95 (RCT+1) 75@ VK/2 8.66

ANNEXURE I-F(ii i)

COREWISE DETAILS OF 12kV NEUTRAL CT for 4MVA 33/11kV T/F

(300-150/5)

No. OF CORE = 1

CoreNo.



Formula for minimumknee-point voltageAt CTSecondary resistance at750C at 300A tap (Volt)


MinimumInsulation Voltage(kV)

1 2 3 4 5 6 71 REF

PROTECTION300-150/5 PS 95 (RCT+1) 75@ VK/2 8.66

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ANNEXURE-I

GUARANTEED TECHNICAL PARTICULARS

(To be filled in by the Supplier separately for each type and voltage rating).

1. Manufacturer's Name

2. Type/Installation.

3. Conforming to standard.

4. Rated voltage.

5. Rated frequency.

6. Detail of cores.

*Core No. I II III IV V

6.1 Purpose of cores.6.2 Rated Secondary Current.

6.3 Class of accuracy.

6.4 Accuracy limit factor.

6.5 Formula governing minimum

knee point voltage at CT

Secondary resistance corrected

to 75 C.

6.6 Instrument security factor.

6.7 Secondary limiting voltage.

6.8 Maximum Secondary resistance

corrected to 75 C.

6.9 Rated burden.

6.10 Exciting currentfor Distance protection

core at Vk, for Bus

Bar protection core & REF Core at

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Vk/2. and for differential protection

Core at Vk/4

* No. of cores as per applicability for a particular type of current

7. Rated primary current.

8. Rated short time withstand

current (kA rms) for

1 second duration.

9. Rated dynamic withstand

current (kA peak).

10. Rated continuous thermal current (pu).

11. One minute power

frequency withstand

voltage (kV rms)

a) Dry

b) Wet

12. 1.2/50 micro-second

impulse withstand voltage (kV peak)

13. One minute power

frequency withstand

voltage of secondary

winding (kV rms)

14. Minimum creepage

distance (mm)

15. Maximum creepage factor.

16. Winding

a) No. of primary turns

b) Primary amp. turns

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(Dynamic condition)

c) Current density

d) Area of Cross-section & material

i) Primary turnsii) Secondary turns

17. I.S. to which the oil conforms.

18. Weight of oil (kg).

19. Quantity of oil (Ltrs)

20. Total weight (kg).

21. Maximum shipping weight (kg)

22. Overall dimension.

23. Mounting details.

24. Maximum permissible

temperature rise of

winding when referred

to maximum ambient

temperature of 50 C

in terms of clause 7.2

(Table 2 of IS:2705

Part-1-1992 ) or

Equivalent IEC

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111_CT-NCT spec-Dec, 2012

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