Cables Dm Vindh1

NATIONAL THERMAL POWER CORPORATION LTD.

2 x 500MW VINDHYACHAL STPP STAGE-III

DESIGN CALCULATIONS FOR CABLE SIZING AND SELECTION

NTPC DOC. NO. 2240-108-23PE-PVE-K-026

BHEL DOC. NO. PE-DC-209-507-E003

REVISION 0

BHARAT HEAVY ELECTRICALS LIMITED POWER SECTOR

PROJECT ENGINEERING MANAGEMENT

NEW DELHI, INDIA

S. NO. NO. OF SHEETS

1 DESIGN CALCULATIONS 14

2 ANNEXURE-A: SELECTION TABLE FOR CABLE SIZES

TABLE-A: CABLE SELECTION TABLE FOR 11 kV SYSTEM 4

TABLE-B1: 2TABLE-B2: 1

TABLE-C: 1

TABLE-D: 1

TABLE-E: 1

TABLE-F:

TABLE-G: 1

TABLE-H: 1

TABLE-I: 1

3 ANNEXURE-B: CABLE DATA 21

4 ANNEXURE-C: SUMMARY SHEET (CABLE SIZES FINALISED FOR THE PROJECT) 1

INDEX:

Design Calculations For Cable Sizing & Selection Doc. No. PE-DC-209-507-E003

2 x 500 MW Vindhyachal STPP, Stage-IIIRev No. 0January 21, 2004

CABLE SELECTION TABLE FOR 3.3 kV SYSTEM

CONTENTS

CABLE SELECTION TABLE FOR 415 V SUPPLY FEEDERS: CABLES LAID IN AIR

CABLE SELECTION TABLE FOR 3.3 kV (VFD SYSTEM)

CABLE SELECTION TABLE FOR 415 V SUPPLY FEEDERS: CABLES LAID IN TRENCH

CABLE SELECTION TABLE FOR 240 V AC SUPPLY SYSTEM: CABLES LAID IN AIR

CABLE SELECTION TABLE FOR 220 V DC SYSTEM: CABLES LAID IN AIR

CABLE SELECTION TABLE FOR 415 V MOTOR FEEDERS: CABLES LAID IN AIR

CABLE SELECTION TABLE FOR 415 V MOTOR FEEDERS: CABLES LAID IN TRENCH

CABLE SELECTION TABLE FOR 240 V AC SUPPLY SYSTEM: CABLES LAID IN TRENCH

1.0

(a) Scope(b)(c)(d)(e)(f)

2.0 SCOPE

2.1

2.2a)b)c)d)e)f)g)

2.3

3.0 TYPE OF CABLES SELECTED

3.1

a) 11kV & 3.3 kV Power Cables

24 V DC system power cables.

Type of cables selected

The following type of cables are selected in line with NTPC specification Vol-II, Part-B, Section:E18.

The details of cables for the following are excluded from the scope of this document:

This document is intended to cover the selection and/or sizing calculations of 11kV, 3.3 kV, 415V AC, 240V AC and 220V DC power cables and control cables required for the interconnection of electrical equipment.

The cables for 11 kV & 3.3 kV system are 1-core or 3-core unearthed grade with circular stranded aluminium conductor, conductor screening, crosslinked polyethylene (XLPE) insulation, insulation screening, core identification by colour coding, distinct extruded inner sheath of PVC type ST2 material for all armoured and multicore unarmoured cables only (inner sheath not envisaged for single core unarmoured cables), aluminium wire armour for single core cable and GS formed wire armour as per IS: 3975 for multicore cables (armour provided for directly buried cables only) and extruded PVC Type ST2 outer sheath with FRLS properties, generally conforming to IS:7098 (Part-2). The conductor screen and insulation screen shall both be extruded semi-conducting compound and shall be applied along with XLPE insulation in a single operation by triple extrusion process. Method of curing shall be "Dry curing/ gas curing".

ESP integral cabling

Switchyard cablingAuxiliary plants in the scope of NTPC

The details of screened control cables shall be covered in C& I documentation such as wiring diagrams/ block cable diagrams, which will be submitted separately.

Sample calculationsSelection Tables For Cable SizesCable Data

Turbine & Generator integral cabling

Design Calculations For Cable Sizing & Selection

2 x 500 MW Vindhyachal STPP, Stage-III

Doc. No. PE-DC-209-507-E003Rev No. 0January 21, 2004

CONTENTS

This document covers the following:

ID Fan VFD integral cabling

Basis for design calculations for cable sizing

Steam Generator integral cabling

Separate documentation shall be submitted separately for the above.

Maximum conductor temperature for normal operation is 90 deg. C and for short circuit conditions, 250 deg. C. Minimum conductor size is 150 sq. mm.

3 of 16




b) 1.1 kV Power Cables (sizes 150 sq. mm. and above)

c) 1.1 kV Power Cables (below 150 sq. mm.)

d)

3.2 Standards applicable:

a)

b)

c)

4.0 BASIS FOR DESIGN CALCULATIONS FOR CABLE SIZING

4.1 DESIGN CONSIDERATIONS: POWER CABLES

4.1.1 In general, Power Cables are sized to satisfy the following three criteria:

(a)

(b)

(c)

Control cables

Short circuit current withstand capacity for applicable fault current and duration.

Control cables are of 650/ 1100 V earthed grade with stranded plain annealed copper conductor, PVC Type-A insulation, core identification by colour coding (upto five cores)/ number marking (more than five cores), distinct extruded inner sheath of PVC Type ST1 material, GS formed wire armour as per IS: 3975 (armour provided for directly buried cables only) and extruded PVC type ST1 outer sheath with FRLS properties, generally conforming to IS:1554 (Part-1). Maximum conductor temperature for normal operation is 70 deg. C and for short circuit conditions, 160 deg. C. The minimum conductor cross section is 1.5 sq. mm.

Power cables for the 415 V AC, 240V AC and 220V DC systems are 2-core, 3-core, 31/2-core and 4-core 650/ 1100 V earthed grade with stranded aluminium/copper conductor, PVC Type-A insulation, core identification by colour coding, distinct extruded inner sheath of PVC Type ST1 material (for armoured cables and multicore unarmoured cables only), aluminium wire armour for single core cable and GS formed wire armour as per IS: 3975 for multicore cables (armour provided for directly buried cables only) and extruded PVC Type ST1 outer sheath with FRLS properties, generally conforming to IS:1554 (Part-1). Maximum conductor temperature for normal operation is 70 deg. C and for short circuit conditions, 160 deg. C. The minimum conductor cross section is 2.5 sq. mm. for copper and 6 sq. mm. for aluminium conductor.

IS:7098 Part-2

Specification for Cross Linked Polyethylene Insulated PVC Sheathed Cables (for working voltages up to and including 1100 V).

IS:7098 Part-1

Specification for Cross Linked Polyethylene Insulated PVC Sheathed Cables (for working voltages from 3.3 kV up to and including 33 kV).

IS:1554 Part-1 Specification for PVC insulated (Heavy Duty) Electric Cables (for working voltages up to and including 1100 V).

Full load current carrying capacity under installation conditions (i.e. with suitable derating factors to cover site conditions such as ambient and ground temperatures, grouping and soil resistivity and cable laying configuration).

Maximum voltage drop limits under steady state / transient state as applicable.

Power cables for the 415 V AC, 240V AC system and 220V DC system are 1-core, 3-core and 3-1/2-core, 1100 V earthed grade with stranded aluminium conductor, crosslinked polyethylene (XLPE) insulation, core identification by colour coding, distinct extruded inner sheath of PVC type ST2 material for all armoured cables and multicore unarmoured cables only (inner sheath not envisaged for single core unarmoured cables), Al wire armour for single core cables and GS formed wire armour as per IS: 3975 for multicore cables (armour provided for directly buried cables only) and extruded PVC type ST2 outer sheath with FRLS properties, generally conforming to IS:7098 (Part-1). Maximum conductor temperature for normal operation is 90 deg. C and for short circuit conditions, 250 deg. C. Minimum conductor cross section is 150 sq. mm.

4 of 16




4.1.2

(a)

(b)

Cosφ= 0.9Efficiency= 0.9

0.75

(c)

(d)

Cosφ= 0.85Efficiency= 0.9

(e)

0.850.9

(f)

Cosφ= 0.85Sinφ= 0.53

(g)

0.520.710.81

Cosφ= 0.3Sinφ= 0.95

(h)

(i)

The neutral cable is sized on the basis of half the uprated load current.

220 V DC feeders:

3.3 kV Transformer feeders:

Power factor (except for CW pump motor) and efficiency for 11 kV motors are considered as below :

240 V AC feeders:

Power factor for 415 V supply feeders are considered as below :

Efficiency for ID fan=

Current ratings corresponding to the full load current of motor.

The normal current ratings for the feeders are considered as under:

Current ratings corresponding to the full load current of motor.

11 kV Transformer feeders:Current ratings corresponding to MVA rating of the transformer.

11 kV Motor feeders:

Power Factor for CW pump motor=

3.3 kV Motor feeders:

Current ratings corresponding to MVA rating of the transformer.

415 V Supply feeders:Presently considered as 90 % of the standard busbar rating, since LVAC system design is in progress. However, the actual cable sizes will be deduced on the basis of the actual current loading of each switchboard / MCC / ACDB.

0.7 x 0.74=

415 V Motor feeders:

Up to 1.0 kW =Power factor x efficiency for 415 V motors under steady state conditions are considered as below :

Normal current ratings for motor feeders are taken as the full load current corresponding to the highest rated motor of the group. For transient voltage drop consideration, the starting current is taken as 7.2 times the full load current.

0.84 x 0.84=40.1 to 200 kW=

Under transient conditions,

0.85 x 0.95=

Cable sizes are computed on the basis of different feeder ratings.

3.3 kV feeders (VFD system)

Power Factor for ID fan=

The current ratings for other feeders for VFD system are based on recommendations provided by VFD system supplier.

1.1 to 40 kW=

Cable sizes are computed on the basis of different feeder ratings.

Power factor and efficiency for 3.3 kV motors are considered as below :

5 of 16




(j) Voltage drop limits considered are as under:

i)- Steady State (continuous running condition) 2.5 %ii) 415 V AC Motor Feeders- Steady State (continuous running condition) 2.5 %- Transient State (during motor starting condition) 10 %

iii) 10 V

iv)- Battery to DCDB 1.66 V- Charger to DCDB 1.66 V- DCDB to loads/Motors 4 V

4.2 DESIGN CONSIDERATIONS: CONTROL CABLES

4.2.1

a)

4.2.2

2C, 3C, 4C NIL5C 17C-10C 2

3

4.3 DESIGN INPUT DATA

The following data is used as the basis input data for sizing & selection of cables.

(a) Design ambient temperature: 50 °C

(b) Fault current for 11 kV & 3.3 kV systems: 40 kA RMS

(c) Fault current for 415V systems: 50 kA RMS

(d) Main protection fault clearing time for cables 0.12 sec. (min) to the feeders protected by breakers:

Minimum no. of spare cores in control cables shall be as follows:

(As per NTPC TS E0, Part-B, Cl.1.08)

No sizing calculations are required for control cables. The following considerations are applicable to the selection of these cables:

No. of spare cores (minimum)No. of cores in cable

14C and above

220 V DC Feeders

240 V AC Supply Feeders

415 V AC Supply Feeders

(As per NTPC TS E0, Part-B, Cl.1.08)

(As per NTPC TS E0, Part-B, Cl. 6.0 (vi))

Control cables are of 1.5 mm.& 2.5 mm. cross-section, and with up to 24 cores.

6 of 16




(e) Annexure-B: Cable Technical Data

-

Table-21

Table-23

Table-24

Table-29

Table-30

Table-31

Table-32

Table-33

Table-36

Table-39

Table-42

-

Table-62

Table-63

-

Table-49

Table-51Table-52

Table-54

Table-56Table-58Table-59UCL Table

Rating factors for variation in depth of laying for cables laid directly in ground.Group rating factors for single core cables laid in trefoil formation.Group rating factors for multi core cables.Group rating factor for multi-core cables under the conditions given in Table 59 (A) but the cables are touching.

Rating factors for variation in ground temperature for cables laid direct in ground.

Rating factors for variation in ambient air temperature.Rating factors for variation in thermal resistivity of soil for three single core cables laid direct in ground in trefoil touching.Rating factors for variation in thermal resistivity of soil for twin and multi-core cables laid direct in ground.

Approximate AC resistance of conductor (Ohm/ km) at maximum operating conductor temperature PVC, HR PVC and XLPE cables.Approximate reactance at 50 Hz (Ohms/km), 1.1 kV PVC, HR PVC and XLPE cables.

Current ratings for three core 1.9/ 3.3 kV & 3.3 /3.3 kV XLPE cables according to IS-7098 (II).

Current ratings for three core 11/11 kV XLPE cables according to IS-7098 (II).

Current ratings for two single core 650/1100 V unarmoured or non-magnetic armoured PVC cables according to IS-1554 (I).

Current ratings for two single core 650/1100 V unarmoured or non magnetic armoured 1.1 kV XLPE cables according to IS-7098 (I).

Resistances & Reactances-CABLE CATALOGUE OF UNIVERSAL CABLES LIMITED

Current ratings for three single core 1.9/3.3 kV & 3.3/3.3 kV XLPE cables according to IS-7098 (II).Current ratings for three single core 11/ 11 kV XLPE cables according to IS-7098 (II).

Current ratings for three single core 650/1100 V unarmoured or non-magnetic armoured 1.1 kV XLPE cables according to IS-7098 (1).Current ratings for twin 650/1100 V armoured or unarmoured 1.1 kV XLPE cables to IS-7098 (I).Current ratings for three, three and half and four core 650/1100V armoured or unarmoured 1.1 kV XLPE cables according to IS-7098 (I).

Current ratings for three, three and half and four core 650/1100V armoured or unarmoured PVC cables according to IS-1554 (I).

Current ratings (AC/DC)-CABLE CATALOGUE OF UNIVERSAL CABLES LIMITED

Current ratings for twin 650/1100 V armoured or unarmoured PVC cables according to IS-1554 (I).

Derating factors for installation conditions-CABLE CATALOGUE OF UNIVERSAL CABLES LIMITED

7 of 16




4.3.1

(a)

Fault current Ish = 40 kA RMSFault clearing time t = 0.12 sec. ( min.)

0.094

Therefore, A= 147.41 mm2

150 mm2

(b)

(i) Cables in air

(1) Temperature derating factor (K1)

For 50 deg. C ambient temperature, derating factor (K1)= 0.9

(2)

No. of cores K2 Table ref.Single core 0.92 Table 58 (D)Multi core 0.70 Table 59 (C)

Overall derating factor = K1 x K2= 0.83= 0.63

(ii) Cables laid directly in ground

(1) Temperature derating factor (K3)

For 40 deg. C ground temperature, derating factor = 0.91

(2)

No. of cores K4 Table ref.Single core 1 (*)Multi core 1 (*)

(3) 1

(4) Derating factor for depth of laying (K6)= 1(depth of laying considered=0.9m.)

Overall derating factor = K3 x K4 x K5 x K6

= 0.91= 0.91

(c)

4.3.2

1 no. cable in horizontal formation

(Refer Table-56)

For single core HT cables (KHgs)For multi core HT cables (KHgm)

(*): No group derating is considered as single cable is buried in ground

Derating factor for variation in thermal resistivity of soil (150 deg. C cm/ W) (K5)=(Refer Table-52 & 54)

Such cables as may be required to be buried directly in ground to meet statutory requirements (e.g. for fire fighting system equipment etc.). Derating factors for cables laid directly in ground are listed below:

Group derating factor (K4)=

Arrangement of cables1 no. of trefoil (touching)

3 Trays & 3 no. of trefoils per tray, separated by 2 cable dia3 Trays & 6 cables/tray, cables touching

For single core HT cables (Khas)=For multi core HT cables (Kham)=

Free air circulation conditions (cables laid in cable trays in cable vaults/ overhead pipe-cum-cable trestle) for all cables in Main power house area. Derating factors for cables laid in air are listed below:

( refer Table-51 )

Group derating factor (K2)

Arrangement of cables

where k is a constant (for aluminium conductor XLPE insulation) = (R f A

Nearest standard cable conductor size selected=

CABLE SIZES BASED ON LOAD CURRENT CARRYING CAPACITY : DERATING FACTORS

Cables are rated for laying in the following conditions:

DESIGN INPUTS FOR CABLE SIZING FOR 11 kV & 3.3 kV SYSTEMMINIMUM SIZE FOR SHORT CIRCUIT CURRENT WITHSTAND CAPACITY

All 11 kV and 3.3 kV feeders are circuit breaker protected.

Minimum cross-sectional area to withstand short circuit A= Ish x SQRT(t) / k

( refer Table-49 )

Voltage drop for 11 kV & 3.3 kV cables is found to be insignificant compared to allowable limits, with the sizes chosen on the basis of fault current withstand capacity and load current carrying criteria.

CABLE SIZES BASED ON VOLTAGE DROP CRITERIA

DESIGN INPUTS FOR CABLE SIZING FOR 415 V SYSTEM

8 of 16




(a-1)

Fault current Ish = 50 kA RMSFault clearing time t = 0.12 sec. ( min.)

Minimum cross-sectional area to withstand Short circuit current (A)= Ish.SQRT(t)/k

0.094

Therefore, A (Al. conductor XLPE insulation)= 184.26 mm2

185 mm2

300 mm2

(a-2)

(b)

(i)

(1)

For 50 deg. C ambient temperature, derating factor (K1) for XLPE cables= 0.9For 50 deg. C ambient temperature, derating factor (K7) for PVC cables= 0.81

(2) Group derating factor(K8)

No. of cores K8 Table ref.Single core 3 Trays & 3 no. of trefoils per tray, separated by 2 cable dia 0.92 Table 58 (D) Multi core 6 Trays & 6 no. of cables per tray in air, touching each other 0.68 Table 59 (C)

Overall derating factor K= K1 x K8 (XLPE)= K7 x K8 (PVC)

= 0.83= 0.75= 0.61= 0.55

However to meet voltage drop criteria, cable conductor size selected for aluminium conductor XLPE insulation=

For XLPE, single core LT cables (KLasx)For PVC, single core LT cables (KLasp)For XLPE, multi core LT cables (KLamx)For PVC, multi core LT cables (KLamp)

Cables in air

Free air circulation conditions (cables laid in cable trays in cable vaults/ overhead pipe-cum-cable trestle) for all cables in Main power house area except for cables mentioned at (iii). Derating factors for cables laid in air are listed below:Temperature derating factor (refer Table-51)


CABLE SIZES BASED ON SHORT CIRCUIT CURRENT WITHSTAND CAPACITY- FUSE PROTECTED FEEDERSFor fuse protected feeders, minimum cable size of 2.5 sq. mm. (copper) or 6 sq. mm. (aluminium) is taken in linewith Cl. 5.01 , Part-B, Section-VI, Sub-section-E18 of NTPC Technical Specification.

Cables are rated for laying in the following conditions:CABLE SIZES BASED ON LOAD CURRENT CARRYING CAPACITY : DERATING FACTORS

Outgoing feeders from 415V boards (Circuit breaker protected)

where k is a constant (for Al. conductor XLPE insulation)

Nearest standard cable conductor size for aluminium conductor XLPE insulation=

MINIMUM SIZE FOR SHORT CIRCUIT CURRENT WITHSTAND CAPACITY-CIRCUIT BREAKER PROTECTED FEEDERS

9 of 16




(ii) Cables laid directly in ground

(1)

For 40 deg. C ground temperature, derating factor,K3 (XLPE cables) = 0.91

For 40 deg. C ground temperature, derating factor,K9 (PVC cables)= 0.87

(2)

No. of cores K4 Table ref.Single core 3 no. of trefoils in horizontal formation (touching) 0.68 Table 58 (A)Multi core 3 no. cables in horizontal formation (touching) 0.69 Table 59 (D)

(3) 1

(4) Derating factor for depth of laying (K12)= 1(depth of laying considered=0.75m.)

Overall derating factor K= K3 x K4 x K11 x K12= K9 x K4 x K11 x K12

= 0.62= 0.59= 0.63= 0.60

(iii) Cables in covered trench with restricted air circulation.

(1) 0.9

0.81

(2)

No. of cores K14 Table ref.Single core 0.81 Table 58 (C)Multi core 0.60 UCL Table

= 0.73= 0.66= 0.54= 0.49

For multi core XLPE, LT cables (KLtmx)For multi core, PVC LT cables (KLtmp)

3 Trays & 9 cables/tray, cables touching

Overall derating factor = K1 x K13For single core XLPE, LT cables (KLtsx)For single core PVC, LT cables KLtsp

( refer Table-51 )

Group derating factor (K14)

Arrangement of cables3 Trays & 3 no. of trefoils per tray, separated by 2 cable dia

For single core PVC, LT cables KLgsp

For multi core XLPE, LT cables (KLgmx)For multi core, PVC LT cables (KLgmp)

( refer Table-51 )

Restricted air circulation conditions (cables laid in cable trays in cable trenches e.g. in auxiliary plant areas). Derating factors for cables in covered trench with restricted air circulation are listed below:

Derating factor for variation in thermal resistivity of soil (150 deg. C/cm/W) (K11)=(refer Tables-52 & 54)

(refer Table-56)

For single core XLPE, LT cables (KLgsx)

Such cables as may be required to be buried directly in ground to meet statutory requirements (e.g. for fire fighting system equipment etc.). Derating factors for cables laid in ground are listed below:

Temperature derating factor (refer Table-45)

Group derating factor (K4)=


For 50 deg. C ambient temperature, derating factor (K1) for XLPE cables=

For 50 deg. C ambient temperature, derating factor (K7) for PVC cables=

( refer Table-49 )

( refer Table-49 )

10 of 16




(c) CABLE SIZES BASED ON VOLTAGE DROP CRITERIA (415 V SYSTEM)

Cable size based on voltage drop limits:

The voltage drop for a given cable length under steady state conditions is given by the formula

Voltage drop in %=

Where:I=

l=R= X=

4.3.3

(a)

(b)

(c)

The voltage drop for a given cable length is given by the formula

Voltage drop=

Where:I= Full Load current in Amperes for steady state conditions

l= Feeder length in metresR=

5.0 SAMPLE CALCULATIONS

5.1

5.1.1

(a) Fault Current Criterion

Minimum size = 150 sq. mm. (CB protected feeder)

(b) Load Current Criterion

16000 kVAFull load Current=16000 /(SQRT(3) * 11)= 839.78 AOverall Derating Factor for 3-core HT cables laid in air (KHas)= 0.83Uprated load current=839.78/0.83= 1011.78 AFrom Annex.-B, Table-36, current rating of 1C-300 sq. mm. Cable in air= 518 AHence Cable size for load current=2-1C-300 sq. mm.

Derating factors for 220 V DC system are taken same as for 415 V system listed at 4.3.2 (b) above.

CABLE SIZES BASED ON VOLTAGE DROP CRITERIA

Under starting conditions for LT motors, the voltage drop is also checked with 7.2 times the full load current as starting current and power factor taken as 0.3.

DESIGN INPUTS FOR CABLE SIZING FOR 220 V DC SYSTEM

MINIMUM SIZE FOR SHORT CIRCUIT CURRENT WITHSTAND CAPACITY-FUSE PROTECTED FEEDERSFor fuse protected feeders, minimum cable size of 2.5 sq. mm. (copper) or 6 sq. mm. (aluminium) is taken in linewith Cl. 5.01 , Part-B, Section-VI, Sub-section-E18 of NTPC Technical Specification.

Feeder length in metresAC Resistance of cable in Ohm/km Reactance of cable in Ohm/km at 50 Hz.

CABLE SIZES BASED ON LOAD CURRENT CARRYING CAPACITY : DERATING FACTORS

Full Load current in Amperes for steady state conditionsStarting current for transient conditions (for motor feeders)

FEEDER FROM 11 kV BOARD 9BA TO UNIT AUXILIARY TRANSFORMER # 9CAT01

Final cable size selected is 2-1C-500 sq mm.

Rating Of the Transformer # 9CAT01=

Resistance of cable in Ohm/km

11 kV FEEDERS

1000****2 cortRlI

( ) 100*******3V

SinXCostRlI cor φφ +

11 of 16




5.1.2


Minimum size = 150 sq. mm.(CB protected feeder)


Rating Of MDBFP= 10000 kWFull load Current=10000 /(SQRT(3) * 11*0.9*0.9)= 647.98 AOverall Derating Factor for 1-core HT cables laid in air KHas= 0.83Uprated load current=647.98/0.83= 780.70 A

822 AHence Cable size for load current= 1C-630 sq. mm./ph.

5.2 3.3 kV FEEDERS

5.2.1


Minimum size = 150 sq. mm.(CB protected feeder)


1300 kW297.31 A

Overall Derating Factor for 1-core HT cables laid in air KHas= 0.83Uprated load current=297.31/0.83= 358.20 AFrom Annex.-B, Table-33, current rating of 1C-185 sq. mm. Cable in air= 362 AHence Cable size for load current= 1C-185 sq. mm.

5.3 415 V SUPPLY FEEDERS ( LAID IN AIR)

5.3.1


Minimum size = 300 sq. mm.


567 A0.83

Uprated load current=567/0.83 683.13 A814 A

Hence Cable size for load current= 1C-630 sq. mm./ph

From Annex.-B, Table-36, current rating of 1C-630 sq. mm. cable in air=

From Annex.-B,Table-24, current rating of 1C-630 sq. mm. (Al) Cable in air=

Corresponding to rating (0.9*630)=

The neutral cable is sized on the basis of half the uprated load current. Cable size selected for neutral cable is 1C-400 sq. mm. (Al) sq. mm.

FEEDER FROM 11 kV BOARD 0BA TO MDBFP

Cable sizing for 11 kV feeders is shown in Table-A of Annexure-'A'.

Supply Feeder of standard rating 630 Amp.

Final cable size selected is 2-1C-500 sq mm. /ph

Final cable size selected is 1C-300 sq mm./ph.

Overall Derating Factor for XLPE-1-core LT cables laid in air (KLasx)=

Cable sizing for 3.3 kV feeders is shown in Table-B-1 of Annexure-'A'.

Rating Of FD Fan =

FEEDER FROM 3.3 kV BOARD 9CA TO FD FAN-9A

Cable sizing for 3.3 kV feeders for VFD system is shown in Table-B-2 of Annexure-'A'.

Full load Current=1300/(SQRT(3) * 3.3*0.85*0.9)=

12 of 16




(c) Voltage Drop Criterion

(i)

where:567 A

Resistance (R) of 630 mm2 conductor at 90 deg. C = 0.065 Ohms/km.(Refer Table-62)

0.0765 Ohms/km.(Refer Table-63)Cosφ= 0.85Sinφ= 0.53Feeder length= 50 m.

1.13 %

5.4 415 V SUPPLY FEEDERS ( LAID IN TRENCH)

5.5

5.5.1


Minimum size = 2.5 sq. mm.


1 kWFull load Current=1.0*1000 /(SQRT(3) * 415*0.7*0.74)= 2.69 A

0.55Uprated load current=2.69/0.55= 4.88 A

24 AHence Cable size for load current of 4.88 A= 3C-2.5 sq. mm.


415 V MOTOR FEEDERS, IN AIR

Since this voltage drop is less than the permissible limit of 2.5%, cable size of 1C-630 sq. mm./ph is adequate.

Reactance (X) of 630 mm2 at 90 deg. C with XLPE insulation=

Steady State ConditionsThe voltage drop for a given cable length under steady state conditions is given by the formula:

Voltage drop in % for 1C-630 sq. mm. =

Overall Derating Factor for PVC 3-core LT cables laid in air (KLamp)=

From Annex.-B, Table-24, current rating of 3C-2.5 sq. mm. (Cu) Cable in air=

For motor feeders, the voltage drop is calculated for both steady state (running) conditions, as well as transient state (starting) conditions. The voltage drop is calculated for feeder lengths of 50m, 100m, 150m and 200m. The actual cable size for any load can be chosen after determining it's cabling distance from the feeding switchboard.

For feeder lengths of 100m, 150m and 200 m, cable sizes selected are 1C-630 sq. mm. (Al)/ph, 2-1C-400 sq. mm. (Al)/ph & 2-1C-630 sq. mm. (Al)/ph respectively and the corresponding voltage drops are 2.27 %, 2.28 % and 2.27 % respectively, which are less than the permissible limit of 2.5 %.

Cable sizing for 415 V supply feeders (in air) is shown in Table-C of Annexure-'A'.

Motors rated from 0.01 kW to 1 kW

Corresponding to rating =

Load current (I) in A.=

Cable sizing for 415 V supply feeders (in trench) is shown in Table-D of Annexure-'A'.

( ) 100*******3V


13 of 16




(i)

where:2.69 A

Resistance (R) of 2.5 mm2 Cu conductor at 70 deg. C = 8.89 Ohms/km.(Refer Table-62)Reactance (X) of 2.5 mm2 at 70 deg. C with PVC insulation= 0.106 Ohms/km.(Refer Table-63)Cosφ= 0.7Sinφ= 0.71Feeder length= 50 m.

0.35 %

(ii)

where:19.34 A

Resistance (R) of 2.5 mm2 Cu conductor at 70 deg. C = 8.89 Ohms/km.(Refer Table-62)Reactance (X) of 2.5 mm2 at 70 deg. C with PVC insulation= 0.106 Ohms/km.(Refer Table-63)Cosφ= 0.3Sinφ= 0.95Feeder length= 50 m.

1.12 %

Steady State Conditions

Voltage drop in % for 3C-2.5 sq. mm. for starting current of 19.37 A.=

Since this voltage drop is less than the permissible limit of 10 %, cable size of 1 no. 3C-2.5 sq. mm. is adequate.

The voltage drop for a given cable length under steady state conditions is given by the formula:

Voltage drop in % for 3C-2.5 sq. mm. =

Transient State Conditions

From the above calculations, it is clear that for feeder lengths of 100m, 150m and 200m, steady state voltage drop for 1-3C-2.5 sq. mm. size for load current of 2.69 A. is 0.71 %, 1.06 % and 1.41 % respectively, which is less than the permissible limit of 2.5 %. Hence, cable size of 1 no. 3C-2.5 sq. mm. is adequate.

Since this voltage drop is less than the permissible limit of 2.5%, selected cable size is 1 no. 3C-2.5 sq. mm.


From the above calculations, it is clear that for feeder lengths of 100m, 150m and 200m, steady state voltage drop for 1-3C-2.5 sq. mm. size for starting current of 19.37 A. is 2.23 %, 3.35 % and 4.47 % respectively, which is less than the permissible limit of 10 %. Hence, cable size of 1 no. 3C-2.5 sq. mm. is adequate.

Starting current (Ist) in A.=7.2*I

The voltage drop for a given cable length under transient state conditions is given by the formula:

( ) 100*******3V


( )V

SinXCostRlI ttcorst φφ ******3 +

14 of 16




5.5.2




22 kWFull load Current=22*1000 /(SQRT(3) * 415*0.84*0.84)= 43.38 A

0.55Uprated load current=43.38/0.55= 78.87 AFrom Annex.-B, Table-24, current rating of 3C-50 sq. mm. (Al) Cable in air= 105 AHence Cable size for load current= 3C-50 sq. mm.


(I)

where:43.38 A

Resistance (R) of 50 mm2 conductor at 70 deg. C = 0.77 Ohms/km.(Refer Table-62)Reactance (X) of 50 mm2 at 70 deg. C with PVC insulation= 0.0765 Ohms/km.(Refer Table-63)Cosφ= 0.84Sinφ= 0.54Feeder length= 50 m.

0.62 %

(ii)

where:312.31 A

Resistance (R) of 50 mm2 conductor at 70 deg. C = 0.77 Ohms/km.(Refer Table-62)Reactance (X) of 50 mm2 at 70 deg. C with PVC insulation= 0.0765 Ohms/km.(Refer Table-63)Cosφ= 0.3Sinφ= 0.95Feeder length= 50 m.

1.98 %

From the above calculations, it is clear that for feeder lengths of 100m, 150m and 200 m, transient state voltage drop for 1-3C-50 sq. mm. size for starting current of 312.34 A. is 3.96, 5.94% and 7.92 % respectively, which is less than the permissible limit of 10 %. Hence, cable size of 1-3C-50 sq. mm. is adequate.


Corresponding to rating =


The voltage drop for a given cable length under transient state conditions is given by the formula:Transient State Conditions

Since this voltage drop is less than the permissible limit of 2.5%, cable size of 1 no. 3C-50 sq. mm. is adequate.

From the above calculations, it is clear that for feeder lengths of 100m, 150m & 200 m, steady state voltage dropfor 1-3C-50 sq. mm. size for load current of 43.38 A. is 1.25%, 1.87 and 2.49 % respectively, which is less than the permissible limit of 2.5 %. Hence, cable size of 1 no. 3C-50 sq. mm. is adequate.

Starting current (Ist) in A.=7.2*I

Voltage drop in % for 3C-50 sq. mm. for starting current of 312.31 A.=

Cable sizing for 415 V motor feeders ( in air) is shown in Table-E of Annexure-'A'.

Since this voltage drop is less than the permissible limit of 10 %, cable size of one no. 3C-50 sq. mm. is adequate.

The voltage drop for a given cable length under steady state conditions is given by the formula:

Voltage drop in % for 3C-50 sq. mm. for load current of 43.38A.=

Overall Derating Factor for PVC 3-core LT cables laid in air (KLamp)=

Motors rated from 18.51 kW to 22 kW

( ) 100*******3V


( )V

SinXCostRlI ttcorst φφ ******3 +

15 of 16




5.6

5.7

5.8

5.9

5.9.1 Supply Feeder for 400 A rating




400 A0.83

Uprated load current=400/0.83 481.93 A(From Table-29), current rating of 1C-400 mm2 cable= 669


(I)

where:400 A

Resistance (R) of 630 sq. mm conductor at 90 deg. C = 0.065 Ohms/km.(Refer Table-62)Feeder length= 25 m.

1.30 V

6.0

The voltage drop for a given cable length ( in volts) under steady state conditions is given by the


Voltage drop in volts for 1C-630 sq. mm. for load current of 20 A.=

Cable sizes finalised for the project are indicated at Annexure-C.

Cable sizing for 220 V DC supply feeders (in air) for different feeder lengths is shown in Table-I of Annexure'A'.


cable size as per load current criteria= 1C-400 sq. mm.

Since this voltage drop is less than the permissible limit of 1.66 volts, cable size of 1C-630 sq. mm. is adequate for feeder length of 25 m.

Cable sizing for 415 V motor feeders ( in trench) is shown in Table-F of Annexure-'A'.

Cable sizing for 240 V AC supply feeders (laid in trench) is shown in Table-H of Annexure'A'.

240 V AC SUPPLY FEEDERS, LAID IN AIR

Corresponding to actual loading=

Cable sizing for 240 V AC supply feeders (laid in air) is shown in Table-G of Annexure'A'.

220 V DC SUPPLY FEEDERS (IN AIR)

240 V AC SUPPLY FEEDERS, LAID IN TRENCH

Overall Derating Factor for XLPE single-core LT cables laid in air (KLasx)=

415 V MOTOR FEEDERS, IN TRENCH

1000****2 cortRlI

16 of 16

ANNEXURE- ‘A’: SELECTION TABLE FOR CABLE SIZES

SL. NO. FEEDER DESCRIPTION

NA

ME

PLA

TE k

W

p.f.

Effic

ienc

y

RA

TIN

G

(in k

VA)

FULL

LO

AD

C

UR

REN

T (A

mps

.)

A=I

sh x

sqr

t. (t)

/k

CABLE SIZE BASED ON

S/C CURRENT

sq. mm. K F

AC

TOR

BA

SE C

UR

REN

T (A

mps

.) =F

LC/K

CABLE SIZE AS PER LOAD CURRENT

sq. mm.

SELECTED CABLE SIZE sq. mm. REMARK

A OUT GOING FEEDER FROM 11KV BOARD 9BA

1 TRANSFORMER FEEDER TO UAT#9CAT01 16000 839.78 147.41 150 0.83 1011.79 2-1C-300/ph 2-1C-500/ph

2 TRANSFORMER FEEDER TO 9DAT01 UNIT-9 SERVICE TRANSFORMER

2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

3 TRANSFORMER FEEDER TO 9DBT01 UNIT-9 EP SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

4 TRANSFORMER FEEDER TO 9DCT01 UNIT-9 EP SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

5 TRANSFORMER FEEDER TO 9DDT01 UNIT-9 EP SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

6 TRANSFORMER FEEDER TO 9DET01 UNIT-9 EP SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

7 TRANSFORMER FEEDER TO COOLING TOWER TRANSFORMER # 9A

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

8 TRANSFORMER FEEDER TO ASH HANDLING SERVICE TRANSFORMER # 9A

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

9 CWP#1 (NTPC) 2800 0.75 0.90 4148 217.72 147.41 150 0.83 262.31 1C-120/ph 1C-150/ph

10 PA FAN-9A 2950 0.90 0.90 3642 191.15 147.41 150 0.83 230.31 1C-95/ph 1C-150/ph

11 VFD ID FAN-9A (CH#1) 4050 0.90 0.90 5000 262.43 147.41 150 0.83 316.18 1C-150/ph 1C-150/ph

12 VFD ID FAN-9A (CH#2) 4050 0.90 0.90 5000 262.43 147.41 150 0.83 316.18 1C-150/ph 1C-150/ph

B OUT GOING FEEDER FROM 11KV BOARD 9BB

1 TRANSFORMER FEEDER TO UAT#9CAT01 16000 839.78 147.41 150 0.83 1011.79 2-1C-300/ph 2-1C-500/ph

2 TRANSFORMER FEEDER TO 9DAT02 UNIT-9 SERVICE TRANSFORMER

2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

3 TRANSFORMER FEEDER TO 9DBT02 UNIT-9 EP SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

4 TRANSFORMER FEEDER TO 9DCT02 UNIT-9 EP SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

5 TRANSFORMER FEEDER TO 9DDT02 UNIT-9 EP SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

6 TRANSFORMER FEEDER TO 9DET02 UNIT-9 EP SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

January 21, 2004

2 X 500 MW VINDHYACHAL STPP, STAGE-III

TABLE-A: CABLE SELECTION TABLE FOR 11 kV SYSTEM

DOC. NO:PE-DC-209-507-E003, R-0

(CABLES LAID IN AIR EXCEPT FOR THOSE LISTED OUT IN 'REMARK' COLUMN)

1 of 7


NA

ME

PLA

TE k

W

p.f.

Effic

ienc

y

RA

TIN

G

(in k

VA)

FULL

LO

AD

C

UR

REN

T (A

mps

.)

A=I

sh x

sqr

t. (t)

/k

CABLE SIZE BASED ON

S/C CURRENT

sq. mm. K F

AC

TOR

BA

SE C

UR

REN

T (A

mps

.) =F

LC/K


sq. mm.


January 21, 2004



DOC. NO:PE-DC-209-507-E003, R-0


7 TRANSFORMER FEEDER TO COOLING TOWER TRANSFORMER # 9B

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

8 TRANSFORMER FEEDER TO COOLING TOWER TRANSFORMER # 9C

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

9 TRANSFORMER FEEDER TO ASH HANDLING SERVICE TRANSFORMER # 9B

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

10 CWP#2 (NTPC) 2800 0.75 0.90 4148 217.72 147.41 150 0.83 262.31 1C-120/ph 1C-150/ph

11 PA FAN-9B 2950 0.90 0.90 3642 191.15 147.41 150 0.83 230.31 1C-95/ph 1C-150/ph

12 VFD ID FAN-9B (CH#1) 4050 0.90 0.90 5000 262.43 147.41 150 0.83 316.18 1C-150/ph 1C-150/ph

13 VFD ID FAN-9B (CH#2) 4050 0.90 0.90 5000 262.43 147.41 150 0.83 316.18 1C-150/ph 1C-150/ph

C OUT GOING FEEDER FROM 11KV BOARD 0BA

1 UNIT-9 MDBFP 10000 0.9 0.9 12346 647.98 147.41 150 0.83 780.70 1C-630/ph 2-1C-500/ph

2 TRANSFORMER FEEDER TO SWITCHYARD SERVICE TRANSFORMER-1

1000 52.49 147.41 150 0.63 83.31 3C-25 3C-150

3 TRANSFORMER FEEDER TO BUNKER SERVICE TRANSFORMER-1

1250 65.61 147.41 150 0.63 104.14 3C-25 3C-150

4 TRANSFORMER FEEDER TO 11/ 34.5 kV AWRS TRANSFORMER-1

3000 157.46 147.41 150 0.63 249.94 3C-120 3C-150

5 TRANSFORMER FEEDER TO ASH WATER TRANSFORMER-1 2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

6 TRANSFORMER FEEDER TO ETP SERVICE TRANSFORMER-1 630 33.07 147.41 150 0.63 52.49 3C-25 3C-150

7 TRANSFORMER FEEDER TO CHP TRANSFORMER-1 2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

8 TRANSFORMER FEEDER TO COAL HANDLING PLANT TRANSFORMER

6300 330.66 147.41 150 0.83 398.39 1C-240/ph 1C-500/ph

9 TRANSFORMER FEEDER TO WTP SERVICE TRANSFORMER 1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

10 TRANSFORMER FEEDER TO OFFSITE SERVICES SERVICE TRANSFORMER # 0DDT01

2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

11 TRANSFORMER FEEDER TO STATION SERVICE TRANSFORMER (UNIT-9) # 0DAT01

2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

12 TRANSFORMER FEEDER TO FUEL OIL AREA SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

2 of 7


NA

ME

PLA

TE k

W

p.f.

Effic

ienc

y

RA

TIN

G

(in k

VA)

FULL

LO

AD

C

UR

REN

T (A

mps

.)

A=I

sh x

sqr

t. (t)

/k

CABLE SIZE BASED ON

S/C CURRENT

sq. mm. K F

AC

TOR

BA

SE C

UR

REN

T (A

mps

.) =F

LC/K


sq. mm.


January 21, 2004



DOC. NO:PE-DC-209-507-E003, R-0


D OUT GOING FEEDER FROM 11KV BOARD 0BB

1 TRANSFORMER FEEDER TO STATION SERVICE TRANSFORMER (UNIT-10) # 0DBT01

2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

2 TRANSFORMER FEEDER TO FIRE WATER P/H TRANSFORMER # 0DCT01

2000 104.97 147.41 150 0.91 115.35 3C-50 3C-150 (A) CABLES BURIED DIRECTLY IN GROUND

3 TRANSFORMER FEEDER TO CW SERVICE TRANSFORMER #1 1000 52.49 147.41 150 0.63 83.31 3C-25 3C-150

4 CWP# 5 (NTPC) 2800 0.9 0.75 4148 217.72 147.41 150 0.83 262.31 1C-120/ph 1C-150/ph

5 MAKE-UP/ RAW WATER PLANT TRANSFORMER #1 2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

6 ASH HANDLING PLANT 8000 419.89 147.41 150 0.83 505.89 1C-300/ph 1C-500/ph

7 SILO SERVICE TRANSFORMER #1 1250 65.61 147.41 150 0.63 104.14 3C-25 3C-150


9 TRANSFORMER FEEDER TO RAW WATER P/H AREA SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

E OUT GOING FEEDER FROM 11KV BOARD 0BD

1 TRANSFORMER FEEDER TO STATION SERVICE TRANSFORMER (UNIT-10) # 0DBT02

2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

2 TRANSFORMER FEEDER TO FIRE WATER P/H TRANSFORMER # 0DCT02

2000 104.97 147.41 150 0.91 115.35 3C-50 3C-150 (A) CABLES BURIED DIRECTLY IN GROUND

3 TRANSFORMER FEEDER TO CW SERVICE TRANSFORMER (UNIT-9) # 0DCT03

1000 52.49 147.41 150 0.63 83.31 3C-25 3C-150

4 MAKE-UP/ RAW WATER PLANT 2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

5 ASH HANDLING PLANT 8000 419.89 147.41 150 0.83 505.89 1C-300/ph 1C-500/ph

6 SILO SERVICE TRANSFORMER 1250 65.61 147.41 150 0.63 104.14 3C-25 3C-150


8 TRANSFORMER FEEDER TO RAW WATER P/H AREA SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

3 of 7


NA

ME

PLA

TE k

W

p.f.

Effic

ienc

y

RA

TIN

G

(in k

VA)

FULL

LO

AD

C

UR

REN

T (A

mps

.)

A=I

sh x

sqr

t. (t)

/k

CABLE SIZE BASED ON

S/C CURRENT

sq. mm. K F

AC

TOR

BA

SE C

UR

REN

T (A

mps

.) =F

LC/K


sq. mm.


January 21, 2004



DOC. NO:PE-DC-209-507-E003, R-0


F OUT GOING FEEDER FROM 11KV BOARD 0BC

1 UNIT-10 MDBFP 10000 0.9 0.9 12346 647.98 147.41 150 0.83 780.70 1C-630/ph 2-1C-500/ph

2 TRANSFORMER FEEDER TO SWITCHYARD SERVICE TRANSFORMER-2

1000 52.49 147.41 150 0.63 83.31 3C-25 3C-150

3 TRANSFORMER FEEDER TO BUNKER SERVICE TRANSFORMER-2

1250 65.61 147.41 150 0.63 104.14 3C-25 3C-150

4 TRANSFORMER FEEDER TO 11/ 34.5 kV AWRS TRANSFORMER-1

3000 157.46 147.41 150 0.63 249.94 3C-120 3C-150

5 TRANSFORMER FEEDER TO ASH WATER TRANSFORMER-2 2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

6 TRANSFORMER FEEDER TO ETP SERVICE TRANSFORMER-2 630 33.07 147.41 150 0.63 52.49 3C-25 3C-150


8 TRANSFORMER FEEDER TO COAL HANDLING PLANT TRANSFORMER

6300 330.66 147.41 150 0.83 398.39 1C-240/ph 1C-500/ph

9 TRANSFORMER FEEDER TO WTP SERVICE TRANSFORMER 1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

10 TRANSFORMER FEEDER TO OFFSITE SERVICES SERVICE TRANSFORMER # 0DDT02

2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

11 TRANSFORMER FEEDER TO STATION SERVICE TRANSFORMER (UNIT-9) # 0DAT02

2000 104.97 147.41 150 0.63 166.62 3C-70 3C-150

12 TRANSFORMER FEEDER TO FUEL OIL AREA SERVICE TRANSFORMER

1600 83.98 147.41 150 0.63 133.30 3C-50 3C-150

1

2 In case of change of installation conditions of any feeder cable, the cable size/ type shall be checked for the new installation conditions and changed if required.

NOTES:

Equipment & their ratings are indicated on the basis of Electrical Single Line Diagram for Auxiliary Power Distribution (drawing no. PE-DG-209-565-E001). In case of any change in rating of any of the equipment listed above, or addition of any loads, this table will be suitably amended.

4 of 7

January 21, 2004


Effic

ienc

y

p.f.

NA

ME

PLA

TE k

W

RA

TIN

G

(in

kVA

)

FULL

LO

AD

C

UR

REN

T (A

mps

.)

A=I

sh x

sq

rt. (

t)/k CABLE SIZE

BASED ON S/C

CURRENT sq. mm. K

FA

CTO

R

BA

SE

CU

RR

ENT

(Am

ps.)

=FLC

/k

CABLE SIZE AS PER BASE CURRENT sq. mm.

SELECTED CABLE SIZE

sq. mm.REMARK

A OUT GOING FEEDER FROM 3.3 kV BOARD 9CA

1 CEP-9A 0.85 0.9 900 1176 205.83 147.41 150 0.83 247.99 1C-120/ph 1C-150/ph

2 CEP-9B 0.85 0.9 900 1176 205.83 147.41 150 0.83 247.99 1C-120/ph 1C-150/ph

3 CEP-9C 0.85 0.9 900 1176 205.83 147.41 150 0.83 247.99 1C-120/ph 1C-150/ph

4 FD FAN-9A 0.85 0.9 1300 1699 297.31 147.41 150 0.83 358.20 1C-185/ph 1C-300/ph

5 FD FAN-9B 0.85 0.9 1300 1699 297.31 147.41 150 0.83 358.20 1C-185/ph 1C-300/ph

6 ECW PUMP(TG)-9A 0.85 0.9 270 353 61.75 147.41 150 0.63 98.01 3C-35 3C-150

7 ECW PUMP (TG)-9B 0.85 0.9 270 353 61.75 147.41 150 0.63 98.01 3C-35 3C-150

8 ECW PUMP (TG)-9C 0.85 0.9 270 353 61.75 147.41 150 0.63 98.01 3C-35 3C-150

9 ECW PUMP (SG)-9A 0.85 0.9 380 497 86.91 147.41 150 0.63 137.95 3C-50 3C-150

10 ECW PUMP (SG)-9B 0.85 0.9 380 497 86.91 147.41 150 0.63 137.95 3C-50 3C-150

11 BCWP-9A 0.85 0.9 350 458 80.04 147.41 150 0.83 96.44 1C-25 1C-150/ph

12 BCWP-9B 0.85 0.9 350 458 80.04 147.41 150 0.83 96.44 1C-25 1C-150/ph

13 BCWP-9C 0.85 0.9 350 458 80.04 147.41 150 0.83 96.44 1C-25 1C-150/ph

14 MILL-A 0.7 0.9 525 833 145.80 147.41 150 0.63 231.42 3C-120 3C-150

15 MILL-B 0.7 0.9 525 833 145.80 147.41 150 0.63 231.42 3C-120 3C-150

16 MILL-C 0.7 0.9 525 833 145.80 147.41 150 0.63 231.42 3C-120 3C-150

17 MILL-D 0.7 0.9 525 833 145.80 147.41 150 0.63 231.42 3C-120 3C-150

18 MILL-E 0.7 0.9 525 833 145.80 147.41 150 0.63 231.42 3C-120 3C-150

TABLE-B1: CABLE SELECTION TABLE FOR 3.3 kV SYSTEM



DOC. NO: PE-DC-209-507-E003, R-0

5 of 7

January 21, 2004


Effic

ienc

y

p.f.

NA

ME

PLA

TE k

W

RA

TIN

G

(in

kVA

)

FULL

LO

AD

C

UR

REN

T (A

mps

.)

A=I

sh x

sq

rt. (

t)/k CABLE SIZE

BASED ON S/C

CURRENT sq. mm. K

FA

CTO

R

BA

SE

CU

RR

ENT

(Am

ps.)

=FLC

/k

CABLE SIZE AS PER BASE CURRENT sq. mm.

SELECTED CABLE SIZE

sq. mm.REMARK

TABLE-B1: CABLE SELECTION TABLE FOR 3.3 kV SYSTEM



DOC. NO: PE-DC-209-507-E003, R-0

19 MILL-F 0.7 0.9 525 833 145.80 147.41 150 0.63 231.42 3C-120 3C-150

20 MILL-G 0.7 0.9 525 833 145.80 147.41 150 0.63 231.42 3C-120 3C-150

21 MILL-H 0.7 0.9 525 833 145.80 147.41 150 0.63 231.42 3C-120 3C-150

22 MILL-J 0.7 0.9 525 833 145.80 147.41 150 0.63 231.42 3C-120 3C-150

23 MILL-K 0.7 0.9 525 833 145.80 147.41 150 0.63 231.42 3C-120 3C-150

24 MOTOR FEEDER TO SERVICE AIR COMPRESSOR-A 0.85 0.9 360 471 82.33 147.41 150 0.63 130.69 3C-50 3C-150

25 MOTOR FEEDER TO INSTRUMENT AIR COMPRESSOR-A 0.85 0.9 360 471 82.33 147.41 150 0.63 130.69 3C-50 3C-150

26 MOTOR FEEDER TO INSTRUMENT AIR COMPRESSOR-B 0.85 0.9 360 471 82.33 147.41 150 0.63 130.69 3C-50 3C-150

1

2

NOTES:Equipment & their ratings are indicated on the basis of Electrical Single Line Diagram for Auxiliary Power Distribution (drawing no. PE-DG-209-565-E001). In case of any change in rating of any of the equipment listed above, or addition of any loads, this table will be suitably amended.

In case of change of installation conditions of any feeder cable, the cable size/ type shall be checked for the new installation conditions and changed if required.

6 of 7


VOLT

AG

E R

ATI

NG

(V

)

POW

ER F

AC

TOR

EFFI

CIE

NC

Y

AM

PER

E R

ATI

NG

AC

/ DC

A=I

sh x

sqr

t. (t)

/k

CABLE SIZE BASED ON S/C CURRENT (sq.

mm.) OVE

RA

LL

DER

ATI

NG

FA

CTO

R (k

)

BA

SE C

UR

REN

T (A

mps

.) =A

MPE

RE

RA

TIN

G/K CABLE SIZE AS

PER LOAD CURRENT sq. mm.

SELECTED CABLE SIZE

sq. mm.REMARK

1 FROM VFD TRANSFORMER LV TERMINAL TO LCI PANEL BRIDGE CUBICLE.

2300 664 AC 147.41 150 0.83 800.59 2-1C-240/ph 2-1C-300/ph

2 FROM LCI PANEL ADAPTOR CUBICLE TO DC REACTOR

3300 730 DC 147.41 150 0.83 879.52 2-1C-300/P 3-1C-300/P

3 FROM DC REACTOR TO LCI PANEL ADAPTOR CUBICLE

3300 730 DC 147.41 150 0.83 879.52 2-1C-300/P 3-1C-300/P

4 FROM LCI PANEL BRIDGE CUBICLE TO MOTOR CIRCUIT BREAKER

2300 664 AC 147.41 150 0.83 800.59 2-1C-240/ph 2-1C-300/ph

5 FROM MOTOR CB TO MOTOR TERMINALS

2300 0.9 0.85 664 AC 147.41 150 0.83 800.59 2-1C-240/ph 2-1C-300/ph

CABLE SIZES ARE SELECTED BASED ON

VFD SYSTEM SUPPLIER RECOMMENDATIONS.

SAME SIZE/ CONFIGURATION HAS

BEEN USED FOR VARIOUS 500 MW UNITS IN PROJECTS SUCH AS SIMHADRI, TALCHER,

RIHAND & RAMAGUNDAM ETC.

TABLE-B2: CABLE SELECTION TABLE FOR 3.3 kV GRADE CABLES (VFD SYSTEM)

2 X 500 MW VINDHYACHAL STPP, STAGE-IIIDOC. NO: PE-DC-209-507-E003, R-0 January 21, 2004

S.N

. STANDARD RATING(A)

STANDARD RATING(A)*0.9

Size as per S/C current (mm2) k

fact

or Base Current

Insu

latio

n

Size as per Base Current 50 100 150 200 50 100 150 200

1 1 0.90 NA 0.55 1.64 PVC 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-2.5 (Cu) 0.14 0.29 0.43 0.57


3 5 4.50 NA 0.55 8.18 PVC 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-10(Al) 0.71 1.43 2.14 1.20

4 10 9.00 NA 0.55 16.36 PVC 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-10(Al) 4C-10(Al) 4C-10(Al) 1.43 1.20 1.80 2.40

5 15 13.50 NA 0.55 24.55 PVC 4C-10 (Al) 4C-10 (Al) 4C-10 (Al) 3.5C-25mm2[Al] 3.5C-25mm2[Al] 0.90 1.80 1.07 1.43

6 20 18.00 NA 0.55 32.73 PVC 4C-10 (Al) 4C-10 (Al) 4C-10 (Al) 3.5C-25mm2[Al] 3.5C-25mm2[Al] 1.20 2.40 1.43 1.91

7 25 22.50 NA 0.55 40.91 PVC 4C-16mm2[Al] 3.5C-25mm2[Al] 3.5C-25mm2[Al] 3.5C-25mm2[Al] 3.5C-25mm2[Al] 0.60 1.19 1.79 2.38

8 63 56.70 NA 0.55 103.09 PVC 3.5C-50mm2[Al] 3.5C-50mm2[Al] 3.5C-50mm2[Al] 3.5C-50mm2[Al] 3.5C-95mm2[Al] 0.82 1.64 2.47 1.74

9 100 90.00 NA 0.61 147.54 XLPE 3.5C-150mm2[Al] 3.5C-150mm2[Al] 3.5C-150mm2[Al] 3.5C-150mm2[Al] 3.5C-150mm2[Al] 0.49 0.99 1.48 1.97


11 200 180.00 NA 0.61 295.08 XLPE 3.5C-240mm2[Al] 3.5C-240mm2[Al] 3.5C-240mm2[Al] 3.5C-240mm2[Al] 1C-400mm2[Al]/ph 1C-400mm2[Al]-N

0.66 1.31 1.97 2.16

12 250 225.00 NA 0.61 368.85 XLPE 3.5C-240mm2(Al) 3.5C-240mm2(Al) 3.5C-240mm2(Al) 3.5C-240mm2(Al) 1C-400mm2[Al]/ph 1C-400mm2[Al]-N

0.82 1.64 2.46 2.32

13 400 360.00 NA 0.61 590.16 XLPE 1C-400mm2(Al)/ph1C-400mm2(Al)/ph 1C-400mm2((Al)-N

1C-400mm2(Al)/ph 1C-400mm2((Al)-N

1C-630mm2(Al)/ph 1C-400mm2((Al)-N

2-1C-400mm2(Al)/ph 1C-400mm2((Al)-N 0.96 1.93 2.08 1.93

14 630 567.00 300 0.83 683.13 XLPE 1C-630mm2(Al)/ph 1C-400mm2(Al)-N

1C-630mm2(Al)/ph 1C-400mm2(Al)-N


2-1C-400mm2(Al)/ph 1C-400mm2(Al)-N

2-1C-630mm2(Al)/ph 1C-400mm2(Al)-N 1.13 2.27 2.28 2.27

15 800 720.00 300 0.83 867.47 XLPE 2-1C-400mm2(Al)/ph 1C-400mm2(Al)-N

2-1C-400mm2(Al)/ph 1C-400mm2((Al)-N

2-1C-400mm2(Al)/ph 1C-400mm2((Al)-N

2-1C-630mm2(Al)/ph 1C-400mm2((Al)-N

3-1C-630mm2(Al)/ph 1C-400mm2((Al)-N 0.96 1.93 2.16 1.92


2-1C-400mm2(Al)/ph 1C-400mm2(Al)-N

2-1C-400mm2(Al)/ph 1C-400mm2(Al)-N

2-1C-630mm2(Al)/ph 1C-400mm2(Al)-N

3-1C-630mm2(Al)/ph 1C-400mm2(Al)-N 1.09 2.17 2.43 2.16


2-1C-400mm2(Al)/ph 1C-400mm2(Al)-N

2-1C-400mm2(Al)/ph 1C-400mm2(Al)-N

3-1C-400mm2(Al)/ph 1C-400mm2(Al)-N

3-1C-630mm2(Al)/ph 1C-400mm2(Al)-N 1.21 2.41 2.41 2.40

18 1600 1440.00 300 0.83 1734.94 XLPE 3-1C-400mm2(Al)/ph 2-1C-400mm2(Al)-N

3-1C-400mm2(Al)/ph 2-1C-400mm2(Al)-N

3-1C-630mm2(Al)/ph 2-1C-400mm2(Al)-N

4-1C-630mm2(Al)/ph 2-1C-400mm2(Al)-N

5-1C-630mm2(Al)/ph 2-1C-400mm2(Al)-N 1.29 1.92 2.16 2.30

19 (*) 2086.81 300 0.83 2514.23 XLPE 4-1C-630mm2(Al)/ph 4-1C-630mm2(Al)/ph 4-1C-630mm2(Al)/ph 5-1C-630mm2(Al)/ph 7-1C-630mm2(Al)/ph 1.04 2.09 2.50 2.38

(*): 1500 kVA FEEDER FROM DG TO EMERGENCY BOARD

1

2

NOTES:In the absence of final busbar ratings of various switchboards/ MCCs/ distribution boards/ supply feeders, the cable sizes have been calculated for 0.9 * rated busbar current (i.e. maximum loading of busbar). Cable sizes for different switchboards/ MCCs/ ACDBs shall be chosen from the above based on the actual feeder length.However, the actual cable sizes will be deduced on the basis of actual current loading of each switchboard/ MCC/ ACDB.

In case of change of installation conditions of any feeder cable or length of feeder, the cable size/ type shall be checked for the new installation conditions/ feeder length and changed if required.

TABLE-C: CABLE SELECTION TABLE FOR 415 V SUPPLY FEEDERS (CABLES LAID IN AIR)

CABLE SIZES FOR SUPPLY FEEDER LENGTH (M) STEADY STATE VOLTAGE DROP (%) PERMISSIBLE 2.5%

January 21, 2004DOC. NO:PE-DC-209-507-E003, R-02 X 500 MW VINDHYACHAL STPP, STAGE-III

1 of 7

S.N

. STANDARD RATING(A)

STANDARD RATING(A)*0.9

Size as per S/C current (mm2) k

fact

or Base Current

Insu

latio

n




3 5 4.50 NA 0.49 9.18 PVC 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-10(Al) 0.71 1.43 2.14 1.20

4 10 9.00 NA 0.49 18.37 PVC 4C-2.5 (Cu) 4C-2.5 (Cu) 4C-10(Al) 4C-10(Al) 4C-10(Al) 1.43 1.20 1.80 2.40

5 15 13.50 NA 0.49 27.55 PVC 4C-10 (Al) 4C-10 (Al) 4C-10 (Al) 3.5C-25 (Al) 3.5C-25 (Al) 0.90 1.80 1.07 1.43

6 20 18.00 NA 0.49 36.73 PVC 4C-10 (Al) 4C-10 (Al) 4C-10 (Al) 3.5C-25 (Al) 3.5C-25mm2[Al] 1.20 2.40 1.43 1.91

7 25 22.50 NA 0.49 45.92 PVC 4C-16mm2[Al] 3.5C-25mm2[Al] 3.5C-25mm2[Al] 3.5C-25mm2[Al] 3.5C-25mm2[Al] 0.60 1.19 1.79 2.38

8 63 56.70 NA 0.49 115.71 PVC 3.5C-95mm2[Al] 3.5C-95mm2[Al] 3.5C-95mm2[Al] 3.5C-95mm2[Al] 3.5C-95mm2[Al] 0.43 0.87 1.30 1.74



11 200 180.00 NA 0.54 333.33 XLPE 3.5C-240mm2[Al] 3.5C-240mm2[Al] 3.5C-240mm2[Al] 3.5C-240mm2[Al] 1C-400mm2[Al]/ph 1C-400mm2[Al]-N

0.66 1.31 1.97 2.16

12 250 225.00 NA 0.73 308.22 XLPE 1C-400mm2[Al]/ph 1C-400mm2[Al]-N

1C-400mm2[Al]/ph 1C-400mm2[Al]-N




0.60 1.21 1.81 2.32

13 400 360.00 NA 0.73 493.15 XLPE 1C-400mm2(Al)/ph1C-400mm2(Al)/ph 1C-400mm2((Al)-N

1C-400mm2(Al)/ph 1C-400mm2((Al)-N

1C-630mm2(Al)/ph 1C-400mm2((Al)-N

2-1C-400mm2(Al)/ph 1C-400mm2((Al)-N 0.96 1.93 2.08 1.93

14 630 567.00 300 0.73 776.71 XLPE 1C-630mm2(Al)/ph 1C-400mm2(Al)-N



2-1C-400mm2(Al)/ph 1C-400mm2(Al)-N

2-1C-630mm2(Al)/ph 1C-400mm2(Al)-N 1.13 2.27 2.28 2.27


2-1C-400mm2(Al)/ph 1C-400mm2((Al)-N

2-1C-400mm2(Al)/ph 1C-400mm2((Al)-N

2-1C-630mm2(Al)/ph 1C-400mm2((Al)-N

3-1C-630mm2(Al)/ph 1C-400mm2((Al)-N 0.96 1.93 2.16 1.92


2-1C-400mm2(Al)/ph 1C-400mm2(Al)-N

2-1C-400mm2(Al)/ph 1C-400mm2(Al)-N

2-1C-630mm2(Al)/ph 1C-400mm2(Al)-N

3-1C-630mm2(Al)/ph 1C-400mm2(Al)-N 1.09 2.17 2.43 2.16


2-1C-630mm2(Al)/ph 1C-630mm2(Al)-N

2-1C-630mm2(Al)/ph 1C-630mm2(Al)-N

3-1C-630mm2(Al)/ph 1C-630mm2(Al)-N

3-1C-630mm2(Al)/ph 1C-630mm2(Al)-N 0.90 1.80 1.80 2.40

18 1600 1440.00 300 0.73 1972.60 XLPE 3-1C-630mm2(Al)/ph 2-1C-400mm2(Al)-N

3-1C-630mm2(Al)/ph 2-1C-400mm2(Al)-N

3-1C-630mm2(Al)/ph 2-1C-400mm2(Al)-N

4-1C-630mm2(Al)/ph 2-1C-400mm2(Al)-N

5-1C-630mm2(Al)/ph 2-1C-400mm2(Al)-N 0.96 1.92 2.16 2.30

1

2

TABLE-D: CABLE SELECTION TABLE FOR 415 V SUPPLY FEEDERS (CABLES LAID IN TRENCH)

DOC. NO:PE-DC-209-507-E003, R-0 January 21, 2004

NOTES:In the absence of final busbar ratings of various switchboards/ MCCs/ distribution boards/ supply feeders, the cable sizes have been calculated for 0.9 * rated busbar current (i.e. maximum loading of busbar). Cable sizes for different switchboards/ MCCs/ ACDBs shall be chosen from the above based on the actual feeder length.However, the actual cable sizes will be deduced on the basis of actual current loading of each switchboard/ MCC/ ACDB.



CABLE SIZES FOR SUPPLY FEEDER LENGTH (M) STEADY STATE VOLTAGE DROP (%) PERMISSIBLE 2.5%

2 of 7

S.N

. FROM [kW] TO [kW]

Pow

er

Fact

or

Sinφ

Effic

ienc

y

Pow

er F

acto

r x

Effic

ienc

y

Rat

ed

Cur

rent

[Am

p]

Size

as

per

s/c

curr

ent

k fa

ctor

Upr

ated

cu

rren

t

Size as per Base Current

Insu

latio

n

50 100 150 200 50 100 150 200 50 100 150 200

1 0.01 1.00 0.70 0.71 0.74 0.52 2.69 2.5 0.55 4.88 3C-2.5mm2[Cu] PVC 3C-2.5mm2[Cu] 3C-2.5mm2[Cu] 3C-2.5mm2[Cu] 3C-2.5mm2[Cu] 0.35 0.71 1.06 1.41 1.12 2.23 3.35 4.47

2 1.01 2.00 0.84 0.54 0.84 0.71 3.94 2.5 0.55 7.17 3C-2.5mm2[Cu] PVC 3C-2.5mm2[Cu] 3C-2.5mm2[Cu] 3C-2.5mm2[Cu] 3C-2.5mm2[Cu] 0.62 1.24 1.86 2.48 1.64 3.28 4.92 6.563 2.01 3.70 0.84 0.54 0.84 0.71 7.30 2.5 0.55 13.26 3C-2.5mm2[Cu] PVC 3C-2.5mm2[Cu] 3C-2.5mm2[Cu] 3C-10mm2[Al] 3C-10mm2[Al] 1.15 2.29 1.44 1.92 3.03 6.07 3.93 5.254 3.71 5.50 0.84 0.54 0.84 0.71 10.84 2.5 0.55 19.72 3C-2.5mm2[Cu] PVC 3C-2.5mm2[Cu] 3C-2.5mm2[Cu] 3C-10mm2[Al] 3C-25mm2[Al] 1.70 3.41 2.14 1.14 4.51 9.02 5.85 3.345 5.51 7.50 0.84 0.54 0.84 0.71 14.79 2.5 0.55 26.89 3C-10mm2[Al] PVC 3C-10mm2[Al] 3C-10mm2[Al] 3C-25mm2[Al] 3C-25mm2[Al] 0.97 1.95 1.16 1.55 2.66 5.32 3.42 4.566 7.51 9.30 0.84 0.54 0.84 0.71 18.34 2.5 0.55 33.34 3C-10mm2[Al] PVC 3C-10mm2[Al] 3C-10mm2[Al] 3C-25mm2[Al] 3C-25mm2[Al] 1.21 2.42 1.44 1.92 3.30 6.59 4.24 5.657 9.31 11.00 0.84 0.54 0.84 0.71 21.69 2.5 0.55 39.43 3C-10mm2[Al] PVC 3C-10mm2[Al] 3C-25mm2[Al] 3C-25mm2[Al] 3C-25mm2[Al] 1.43 1.14 1.70 2.27 3.90 3.34 5.01 6.688 11.10 15.00 0.84 0.54 0.84 0.71 29.58 2.5 0.55 53.77 3C-25mm2[Al] PVC 3C-25mm2[Al] 3C-25mm2[Al] 3C-25mm2[Al] 3C-50mm2[Al] 0.77 1.55 2.32 1.70 2.28 4.56 6.83 5.409 15.10 18.50 0.84 0.54 0.84 0.71 36.48 2.5 0.55 66.32 3C-25mm2[Al] PVC 3C-25mm2[Al] 3C-25mm2[Al] 3C-50mm2[Al] 3C-50mm2[Al] 0.96 1.91 1.57 2.10 2.81 5.62 4.99 6.6610 18.51 22.00 0.84 0.54 0.84 0.71 43.38 2.5 0.55 78.87 3C-50mm2[Al] PVC 3C-50mm2[Al] 3C-50mm2[Al] 3C-50mm2[Al] 3C-50mm2[Al] 0.62 1.25 1.87 2.49 1.98 3.96 5.94 7.9211 22.00 27.00 0.84 0.54 0.84 0.71 53.24 2.5 0.55 96.79 3C-50mm2[Al] PVC 3C-50mm2[Al] 3C-50mm2[Al] 3C-50mm2[Al] 3C-95mm2[Al] 0.76 1.53 2.29 1.62 2.43 4.86 7.29 6.0112 27.10 30.00 0.84 0.54 0.84 0.71 59.15 2.5 0.55 107.55 3C-95mm2[Al] PVC 3C-95mm2[Al] 3C-95mm2[Al] 3C-95mm2[Al] 3C-95mm2[Al] 0.45 0.90 1.35 1.80 1.67 3.34 5.01 6.6813 30.10 37.00 0.84 0.54 0.84 0.71 72.95 2.5 0.55 132.64 3C-95mm2[Al] PVC 3C-95mm2[Al] 3C-95mm2[Al] 3C-95mm2[Al] 3C-95mm2[Al] 0.55 1.11 1.66 2.22 2.06 4.12 6.18 8.2414 37.10 45.00 0.85 0.53 0.95 0.81 77.53 2.5 0.55 140.97 3C-95mm2[Al] PVC 3C-95mm2[Al] 3C-95mm2[Al] 3C-95mm2[Al] 3C-95mm2[Al] 0.59 1.19 1.78 2.37 2.19 4.38 6.57 8.7615 45.10 55.00 0.85 0.53 0.95 0.81 94.76 2.5 0.61 155.34 3C-150mm2[Al] XLPE 3C-150mm2[Al] 3C-150mm2[Al] 3C-150mm2[Al] 3C-150mm2[Al] 0.52 1.04 1.55 2.07 2.10 4.19 6.29 8.38

16 55.10 64.75 0.85 0.53 0.95 0.81 111.55 2.5 0.61 182.88 3C-150mm2[Al] XLPE 3C-150mm2[Al] 3C-150mm2[Al] 3C-150mm2[Al] 3C-150mm2[Al] 0.61 1.22 1.83 2.44 2.47 4.94 7.40 9.87



19 75.10 90.00 0.85 0.53 0.95 0.81 155.06 2.5 0.61 254.20 3C-150mm2[Al] XLPE 3C-150mm2[Al] 3C-150mm2[Al] 3C-240mm2[Al] 2-3C-150mm2[Al] 0.85 1.70 1.69 1.70 3.43 6.86 8.09 6.86


21 110.10 125.00 0.85 0.53 0.95 0.81 215.36 2.5 0.61 353.05 3C-240mm2[Al] XLPE 3C-240mm2[Al] 3C-240mm2[Al] 2-3C-150mm2[Al] 2-3C-150mm2[Al] 0.78 1.57 1.77 2.36 3.75 7.49 7.15 9.53

22 125.10 145.00 0.85 0.53 0.95 0.81 249.82 2.5 0.61 409.54 2-3C-150mm2[Al] XLPE 2-3C-150mm2[Al] 2-3C-150mm2[Al] 2-3C-150mm2[Al] 2-3C-240mm2[Al] 0.68 1.37 2.05 1.82 2.76 5.53 8.29 8.69



1

2

DOC. NO: PE-DC-202-507-E003, R-0

TABLE E: CABLE SELECTION TABLE FOR 415 V MOTOR FEEDERS (CABLES LAID IN AIR)

The cable size for any motor shall be chosen from the above table depending upon the rating of the motor and length of feeder.


2 X 500 VINDHYACHAL STPP, STAGE-III

NOTES:

January 21, 2004

CABLE SIZES FOR MOTOR FEEDER LENGTH(IN M.) STEADY STATE DROP PERMISSIBLE 2.5%

TRANSIENT STATE DROP PERMISSIBLE 10%

3 of 7

S.N

. FROM [kW] TO [kW]

Pow

er

Fact

or

Sinφ

Effic

ienc

y

Pow

er F

acto

r x

Effic

ienc

y

Rat

ed

Cur

rent

[Am

p]

Size

as

per

s/c

curr

ent

k fa

ctor

Upr

ated

cu

rren

t

Size as per Base Current

Insu

latio

n

50 100 150 200 50 100 150 200 50 100 150 200



3 2.01 3.70 0.84 0.54 0.84 0.71 7.30 2.5 0.49 14.89 3C-2.5mm2[Cu] PVC 3C-2.5mm2[Cu] 3C-2.5mm2[Cu] 3C-10mm2[Al] 3C-10mm2[Al] 1.15 2.29 1.44 1.92 3.03 6.07 3.93 5.25

4 3.71 5.50 0.84 0.54 0.84 0.71 10.84 2.5 0.49 22.13 3C-2.5mm2[Cu] PVC 3C-2.5mm2[Cu] 3C-2.5mm2[Cu] 3C-10mm2[Al] 3C-25mm2[Al] 1.70 3.41 2.14 1.14 4.51 9.02 5.85 3.34

5 5.51 7.50 0.84 0.54 0.84 0.71 14.79 2.5 0.49 30.18 3C-10mm2[Al] PVC 3C-10mm2[Al] 3C-10mm2[Al] 3C-25mm2[Al] 3C-25mm2[Al] 0.97 1.95 1.16 1.55 2.66 5.32 3.42 4.56




















1

2

The cable size for any motor shall be chosen from the above table depending upon the rating of the motor and length of feeder.


CABLE SIZES FOR MOTOR FEEDER LENGTH(IN M.) STEADY STATE DROP PERMISSIBLE 2.5%

TRANSIENT STATE DROP PERMISSIBLE 10%

NOTES:

TABLE F: CABLE SELECTION TABLE FOR 415 V MOTOR FEEDERS (CABLES LAID IN COVERED TRENCH WITH RESTRICTED AIR CIRCULATION)

2 X 500 MW VINDHYACHAL STPP, STAGE-IIIDOC. NO: PE-DC-202-507-E003, R-0 January 21, 2004

4 of 7

S.N

. LOAD CURRENT (A)

Size as per S/C current

(mm2) k fa

ctor Uprated

Current

Insu

latio

n


1 1 NA 0.55 1.82 PVC 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 0.44 0.89 1.33 1.78


3 10 NA 0.55 18.18 PVC 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-10mm2[Al] 2C-10mm2[Al] 4.45 8.89 5.55 7.40

4 15 NA 0.55 27.27 PVC 2C-10mm2[Al] 2C-10mm2[Al] 2C-10mm2[Al] 2C-10mm2[Al] 2C-25mm2[Al] 2.78 5.55 8.33 4.32







1

2

TABLE-G: CABLE SELECTION TABLE FOR 240 V AC SUPPLY FEEDERS (CABLES LAID IN AIR)


NOTES:The cable size for any load shall be chosen from the above table depending upon the rating of the load and length of feeder.

DOC. NO:PE-DC-209-507-E003, R-0 January 21, 20042 X 500 MW VINDHYACHAL STPP, STAGE-III

CABLE SIZES FOR SUPPLY FEEDER LENGTH (M) STEADY STATE VOLTAGE DROP (V) PERMISSIBLE: 10 V

5 of 7

S.N

. LOAD CURRENT (A)

Size as per S/C current

(mm2) k fa

ctor Uprated

Current

Insu

latio

n




3 10 NA 0.49 20.41 PVC 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-10mm2[Al] 2C-10mm2[Al] 4.45 8.89 5.55 7.40








NOTES:1

2

The cable size for any load shall be chosen from the above table depending upon the rating of the load and length of feeder.


TABLE-H: CABLE SELECTION TABLE FOR 240 V AC SUPPLY SYSTEM (CABLES LAID IN TRENCH WITH RESTRICTED AIR CIRCULATION)

CABLE SIZES FOR SUPPLY FEEDER LENGTH (M) STEADY STATE VOLTAGE DROP (V) PERMISSIBLE: 10 V

2 X 500 MW VINDHYACHAL STPP, STAGE-IIIDOC. NO:PE-DC-209-507-E003, R-0 January 21, 2004

6 of 7

S.N

. LOAD CURRENT(A

)

Size as per s/c current

k factor Uprated Current

Insu

latio

n

Size as per Base Current 10 25 50 100 150 200 500 800 1000 1200 1500 3000

PER

MIS

SIBL

E VO

LTAG

E D

RO

P (V

)

10 25 50 100 150 200 500 800 1000 1200 1500 3000

1 1 2.5 0.55 1.82 PVC 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-10mm2[Al] 2C-25mm2[Al] 2C-25mm2[Al] 2C-25mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 4 0.18 0.44 0.89 1.78 2.67 3.56 3.70 2.30 2.88 3.46 1.60 3.19

2 2 2.5 0.55 3.64 PVC 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-10mm2[Al] 2C-10mm2[Al] 2C-25mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-120mm2[Al] 4 0.36 0.89 1.78 3.56 2.22 2.96 2.88 1.70 2.13 2.55 3.19 3.65

3 5 2.5 0.55 9.09 PVC/ XLPE 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-10mm2[Al] 2C-10mm2[Al] 2C-25mm2[Al] 2C-25mm2[Al] 2C-70mm2[Al] 2C-120mm2[Al] 2C-120mm2[Al] 2C-120mm2[Al] 1C-400mm2[Al] 1C-400mm2[Al] 4 0.89 2.22 1.85 3.70 2.16 2.88 2.66 2.43 3.04 3.65 1.53 3.06

4 10 2.5 0.55 18.18 PVC/ XLPE 2C-2.5mm2[Cu] 2C-2.5mm2[Cu] 2C-10mm2[Al] 2C-10mm2[Al] 2C-25mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-120mm2[Al] 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-630mm2[Al]/P 4 1.78 1.85 3.70 2.88 1.60 2.13 3.04 1.63 2.04 2.45 3.06 3.90

5 16 2.5 0.55 29.09 PVC/ XLPE 2C-10mm2[Al] 2C-10mm2[Al] 2C-10mm2[Al] 2C-25mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-630mm2[Al]/P 2-1C-630mm2[Al]/P 4 1.18 2.96 2.30 1.70 2.55 3.40 1.63 2.61 3.26 3.92 3.12 3.12

6(*) 20 2.5 0.55 36.36 PVC/ XLPE 2C-10mm2[Al] 2C-10mm2[Al] 2C-10mm2[Al] 2C-25mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-120mm2[Al] 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-630mm2[Al]/P 1C-630mm2[Al]/P 1C-630mm2[Al]/P 2-1C-630mm2[Al]/P 4 1.48 3.70 2.88 2.13 3.19 2.43 2.04 3.26 2.60 3.12 3.90 3.90

7 25 2.5 0.55 45.45 PVC/ XLPE 2C-10mm2[Al] 2C-10mm2[Al] 2C-25mm2[Al] 2C-25mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-120mm2[Al] 1C-400mm2[Al]/P 1C-630mm2[Al]/P 1C-630mm2[Al]/P 1C-630mm2[Al]/P 2-1C-400mm2[Al]/P 3-1C-630mm2[Al]/P 4 1.85 1.80 3.60 2.66 3.99 3.04 2.55 2.60 3.25 3.90 3.83 3.25

8 35 2.5 0.55 63.64 PVC/ XLPE 2C-25mm2[Al] 2C-25mm2[Al] 2C-25mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-120mm2[Al] 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-630mm2[Al]/P 2-1C-400mm2[Al]/P - - - 4 1.01 2.52 1.86 3.72 3.19 1.43 3.57 3.64 3.57 - - -

9 50 2.5 0.55 90.91 PVC/ XLPE 2C-70mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-120mm2[Al] 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-630mm2[Al]/P 2-1C-630mm2[Al]/P - - - - 4 0.53 1.33 2.66 3.04 1.53 2.04 3.25 2.60 - - - -

10 80 2.5 0.55 145.45 PVC/ XLPE 2C-70mm2[Al] 2C-70mm2[Al] 2C-70mm2[Al] 2C-120mm2[Al] 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-400mm2[Al]/P - - - - - - 4 0.85 2.13 2.43 1.63 2.45 3.26 - - - - - -

11 100 2.5 0.55 181.82 PVC/ XLPE 2C-120mm2[Al] 2C-120mm2[Al] 2C-120mm2[Al] 2C-120mm2[Al] 1C-400mm2[Al]/P - - - - - - - - - 0.61 1.52 3.04 2.04 - - - - - - - -

12 400 2.5 0.83 481.93 XLPE 1C-400mm2[Al]/P 1C-400mm2[Al]/P 1C-630mm2[Al]/P 2-1C-630mm2[Al]/P 4-1C-630mm2[Al]/P - - - - - - - - 1.66 0.82 1.30 1.30 1.30 - - - - - - - -

13 850 300.0 0.83 1024.10 XLPE 2-1C-400mm2[Al]/P 2-1C-400mm2[Al]/P 2-1C-630mm2[Al]/P 4-1C-630mm2[Al]/P 8-1C-630mm2[Al]/P - - - - - - - - 1.66 0.87 1.38 1.38 1.38 - - - - - - - -

1

2

3

4

TABLE I: CABLE SELECTION TABLE FOR 220 V DC SYSTEM (CABLES LAID IN AIR)

January 21, 2004

CABLE SIZES FOR SUPPLY FEEDER LENGTH (M)

NOTES:

STEADY STATE DROP IN VOLTS

(*): An actual load current of 20 A is considered for cable sizing of 32 A feeders required to be provided for non-Main Plant Turnkey package areas for which 220 V DC feeders are to be provided from station 220 V DC system.

DOC. NO: PE-DC-202-507-E003, R-02 X 500 MW VINDHYACHAL STPP, STAGE-III


The cable size for any load shall be chosen from the above table depending upon the rating of the load and length of feeder.

Cables of sizes 150 sq. mm. and above are with XLPE insulation, while all others are with PVC insulation.

CABLE SIZES FOR BATTERY TO DCDB & CHARGER TO DCDB

CABLE SIZES FROM DCDB TO LOAD

1 of 1

ANNEXURE- ‘B’:

CABLE DATA

ANNEXURE- ‘C’:

SUMMARY SHEET

SUMMARY SHEET:

3.3/ 3.3 kV, XLPE INSULATED

POWER CABLES

1.1 kV, XLPE INSULATED POWER

CABLES

UNARMOURED, Al. CONDUCTOR

ARMOURED, Al. CONDUCTOR



UNARMOURED, Al CONDUCTOR

ARMOURED, Al CONDUCTOR

UNARMOURED, Cu CONDUCTOR

ARMOURED, Cu CONDUCTOR

UNARMOURED, Cu CONDUCTOR

ARMOURED, Cu CONDUCTOR

1C-500 3C-150 1C-300 1C-630 2C-2.5 3.5C-25 2C-2.5 5C-6 2C-1.5 2C-2.51C-150 1C-150 1C-400 2C-10 3.5C-50 3C-2.5 3C-1.5 5C-2.53C-150 3C-150 3C-240 2C-25 4C-2.5 5C-1.5 7C-2.5

3C-150 2C-70 7C-1.5 14C-2.53.5 C-240 2C-120 10C-1.5 16C-2.53.5 C-150 3C-10 12C-1.5

3C-25 14C-1.53C-50 19C-1.53C-95 27C-1.5

3.5C-25 2C-2.53.5C-50 3C-2.53.5C-95 4C-2.54C-10 5C-2.5

10C-2.514C-2.5

Doc. No. PE-DC-209-507-E003

Rev No. 0January 21, 2004



1.1 kV, PVC INSULATED POWER CABLES 1.1 kV, PVC INSULATED CONTROL CABLES

11/ 11 kV, XLPE INSULATED POWER CABLES

POWER/ CONTROL CABLE SIZES FINALISED FOR THE PROJECT

SHT 1 OF 1

Date post:	08-Apr-2015
Category:	Documents
Upload:	abhinav-tyagi
View:	392 times
Download:	0 times

Cables Dm Vindh1

Documents