cable size calculations.xls

Cable Size Calculation Max. Fault Level = VH (kV) = VL  (kV)= t (sec) = De - Rating Factor 

200 33 11 0.5 0.466088

ISC (kA) =

3.4991

33 kV System

Sl. No.

1 2 3 4 5 6 7 8 9 10 11 12 13

Substaion

Sonarpur (6 ( 6.3//6.3) Barrackpore (6.3//6.3) Anantpur (6.3//6.3) Abdalpur (6.3//6.3) Kalitala (6.3//3.0) (3//3.15) Belmuri (6.3//6.3.0) Tarui (6.3//6.3) (6.3//3.0) Chapra (6.3//3.0) (3.0//3.0) Joyshree (6.3//6.3) Raninagar (3.0//3.0) Nakashipara (5//3) (3//3.15) University Gate (6.3//5) Raghunathpur

No. of Power Traf 

3 2 3 3 3 2 4 3 2 2 2 2 2 3

Power Trafo. Capacity (MVA) 6.3 6.3 6.3 6.3 6.3 3.15 6.3 6.3 6.3 6.3 3 6.3 3 5 3.15 6.3 6.3

11 kV System

(Ω)

IF (kA)

ZTRANS ZBASE ZTRAN ZTOTAL SF. F.(EQVT.) ZL (Ω) (Ω) (Ω) (Ω) (Ω)

5.445 5.445 5.445 5.445 5.445 5.445 5.445 5.445 5.445 5.445 5.445 5.445 5.445 5.445 5.445 5.445 5.445

110.2 110.2 110.2 110.2 110.2 55.11 110.2 110.2 110.2 110.2 52.49 110.2 52.49 87.48 55.11 110.2 110.2

172.86 172.86 172.86 172.86 172.86 345.71 172.86 172.86 172.86 172.86 363.00 172.86 363.00 217.80 345.71 172.86 172.86

ZSYS

12.36 12.36 12.36 12.36 12.36 21.61 12.36 12.36 12.36 12.36 21.61 12.36 22.69 15.57 21.61 12.36 12.36

6.18 6.18 6.18 6.18 8.00 11.06 6.18 6.18 8.00 8.00 11.06 6.18 11.06 9.24 11.06 6.90 4.42

11.62 1.29 11.62 1.29 11.62 1.29 11.62 1.29 13.45 1.49 16.51 1.83 11.62 1.29 11.62 1.29 13.45 1.49 13.45 1.49 16.51 1.83 11.62 1.29 16.51 1.83 14.69 1.63 16.505 1.8339 12.345 1.3717 9.869 1.0966

ISC (kA)

I (kA)

4.92 3.48 4.92 3.48 4.92 3.48 4.92 3.48 4.25 3.01 3.46 2.45 4.92 3.48 4.92 3.48 4.25 3.01 4.25 3.01 3.46 2.45 4.917 3.48 3.463 2.45 3.892 2.75 3.463 2.45 4.63 3.27 5.792 4.095

Bank Size (kVAR) 2000 1000 200 200 750 500 1500 1500 1250 750 500 1000 200 500 500 1750 250

IFL (A)

IFL IFL (De- (IFL+20 Rated % OF ) (kA) IFL) (kA)

105.0 225 52.5 113 10.5 23 10.5 23 39.4 84 26.2 56 78.7 169 78.7 169 65.6 141 39.4 84 26.2 56 52.5 113 10.5 23 26.2 56 26.2 56 91.9 197 13.12 28.15

270.27 135.13 27.03 27.03 101.35 67.57 202.70 202.70 168.92 101.35 67.57 135.13 27.03 67.57 67.57 236.48 33.78

Cable Size (sq. mm.) 120 95 95 95 95 95 95 95 95 95 95 95 95 95 95 120 95