Cable Current Rating

1 1 1.8 8.3 76 7.41 8.9 0.1391 1 1.8 8.8 91 4.61 5.54 0.13

1 x 10 re 1 1 1.8 9.7 110 3.08 3.7 0.121 x 16 rm 7 1 1.8 11.5 145 1.91 2.3 0.1081 x 25 rm/v 6 1.2 1.8 12.5 140 1.2 1.44 0.1031 x 35 rm/v 6 1.2 1.8 14 230 0.868 1.04 0.11 x 50 rm/v 6 1.4 1.8 15.5 295 0.641 0.77 0.0971 x 70 rm/v 12 1.4 1.8 17 375 0.443 0.532 0.0911 x 95 rm/v 15 1.6 1.8 19.5 485 0.32 0.385 0.0891 x 120 rm/v 15 1.6 2 21.5 600 0.253 0.305 0.0871 x 150 rm/v 15 1.8 2 23.5 710 0.206 0.249 0.0861 x 185 rm/v 30 2 2 25.5 860 0.164 0.199 0.0851 x 240 rm/v 30 2.2 2 28.5 1090 0.125 0.152 0.0831 x 300 rm/v 30 2.4 2 32 1320 0.1 0.123 0.0831 x 400 rm/v 53 2.6 2.2 36 1670 0.0778 0.0975 0.0821 x 500 rm/v 53 3 2.2 40 2100 0.0605 0.0767 0.0811 x 630 rm/v 53 3.4 2.4 45 2680 0.0469 0.0614 0.0811 x 800 rm/v 53 3.4 2.4 49 3250 0.0367 0.0501 0.0791 x 1000 rm/v 53 3.4 2.6 54 3980 0.0291 0.042 0.077

2 x 1.5 re 1 0.8 0.3 1.8 11.5 150 18.1 21.72 x 2.5 re 1 0.9 0.3 1.8 13 185 12.1 14.52 x 4 re 1 1 0.3 1.8 14 225 7.41 8.92 x 6 re 1 1 0.3 1.8 15.5 290 4.61 5.542 x 10 re 1 1 0.3 1.8 17 335 3.08 3.72 x 16 rm 7 1 0.3 1.8 20 470 1.91 2.32 x 25 rm/v 6 1.2 0.3 2 23 650 1.2 1.442 x 35 rm/v 6 1.2 0.3 2 25.5 790 0.868 1.042 x 50 rm/v 6 1.4 0.3 2 28.5 1010 0.641 0.773 x 1.5 re 1 0.8 0.3 1.8 12 165 18.1 21.73 x 2.5 re 1 0.9 0.3 1.8 13.5 205 12.1 14.53 x 4 re 1 1 0.3 1.8 15 250 7.41 8.93 x 6 re 1 1 0.3 1.8 16.5 320 4.61 5.543 x 10 re 1 1 0.3 1.8 17.5 380 3.08 3.73 x 16 rm 7 1 0.3 1.8 21 530 1.91 2.34 x 1.5 re 1 0.8 0.3 1.8 13 185 18.1 21.74 x 2.5 re 1 0.9 0.3 1.8 14.5 230 12.1 14.54 x 4 re 1 1 0.3 1.8 16 285 7.41 8.9

Table 1. Unarmoured Single core power cables type AYY 650/1100 V Go to Top

No. of Cores & Cross Sectional Area NoXmm2

Conductor (Al) minimum no. of wires No.

Thick ness of PVC insulation (nominal) mm

Thickness of PVC outer sheath (nominal) mm

Approx. OD mm

Approx. Net weight of cable kg/km

Max. DC resistance at 20o C

Approx. AC resistance at 70o C Ohm/km

Approx. Reactance at 50 Hz Ohm/km

1 x 4 re1 x 6 re

Table 2 Unarmoured Twin and multi-core power cables Type AYY 650/1100 V Go to Top

No. of Cores & Cross Sectional Area NoXmm2

Conductor (Al) minimum no. of wires No.

Thick ness of PVC insulation (nominal) mm

Thickness of common covering minimum extruded mm

Thickness of PVC outer sheath (nominal) mm

Approx. OD (mm)

Approx. Net weight of cable kg/km

Max. DC resistance at 20oC Ohm/km

Approx. AC resistance at 70o C Ohm/km

http://www.powertips.org/tlinks/cab_data.htm#Top

http://www.powertips.org/tlinks/cab_data.htm#Top

4 x 6 re 1 1 0.3 1.8 18 370 4.61 5.544 x 10 re 1 1 0.3 1.8 19 440 3.08 3.74 x 16 rm 7 1 0.3 2 23.5 640 1.91 2.33 x 25 sm 6 1.2 0.3 2 21.5 520 1.2 1.443 x 35 sm 6 1.2 0.3 2 23.5 640 0.868 1.043 x 50 sm 6 1.4 0.3 2 27 830 0.641 0.773 x 70 sm 12 1.4 0.4 2.2 31 1100 0.443 0.5323 x 95 sm 15 1.6 0.4 2.2 35 1440 0.32 0.3853 x 120 sm 15 1.6 0.4 2.2 37 1690 0.253 0.3053 x 150 sm 15 1.8 0.5 2.4 41 2060 0.206 0.2493 x 185 sm 30 2 0.5 2.6 45 2560 0.164 0.1983 x 240 sm 30 2.2 0.6 2.8 51 3330 0.125 0.1523 x 300 sm 30 2.4 0.6 3 58 4100 0.1 0.1233 x 400 sm 53 2.6 0.7 3.4 65 5200 0.0778 0.09753 x 500 sm 53 3 0.7 3.6 74 6580 0.0605 0.0767

6 1.2/1.0 0.3 2 24 620 1.2 1.44

6 1.2/1.0 0.3 2 25 940 0.868 1.04

6 1.4/1.2 0.3 2 29 950 0.641 0.77

12 1.4/1.2 0.4 2.2 33 1250 0.443 0.532

15 1.6/1.4 0.4 2.2 38 1650 0.32 0.385

15 1.6/1.4 0.5 2.4 41 2010 0.253 0.305

15 1.8/1.4 0.5 2.4 44 2360 0.206 0.249

30 2.0/1.6 0.5 2.6 50 2980 0.164 0.198

30 2.2/1.6 0.6 3 57 3930 0.125 0.152

30 2.4/1.8 0.6 3.2 63 4820 0.1 0.123

53 2.6/2.0 0.7 3.4 70 6020 0.0778 0.0975

53 3.0/2.2 0.7 3.8 80 7670 0.0605 0.07674 x 25 sm 6 1.2 0.3 2 24 650 1.2 1.444 x 35 sm 6 1.2 0.3 2 27 800 0.868 1.044 x 50 sm 6 1.4 0.4 2.2 32 1090 0.641 0.77

3½ x 25/16 sm/rm

3½ x 35/16 sm/rm

3½ x 50/25 sm

3½ x 70/35 sm

3½ x 95/50 sm

3½ x 120/70 sm

3½ x 150/70 sm

3½ x 185/95 sm

3½ x 240/120 sm

3½ x 300/150 sm

3½ x 400/185 sm

3½ x 500/240 sm

Table 3 Armoured Twin and Multicore power cables type AYWY and AYFY 650/1100 V Go to Top

Type AYWY Go to Top

No. of cores & Cross Sectional area (no x sq.mm

Min. No. of wires

Thick ness of PVC insulation (mm)

Thick ness of common covering (mm)

Armour Size (mm)

Thick ness of PVC outer sheath (mm)

Approx. OD (mm)

Approx. Net wt of cable (kg/km)

Max. DC resistance at 20º C (Ohm/km)

http://www.powertips.org/tlinks/cab_data2.htm#Top


2 x 1.5 re 1 0.8 0.3 1.4 1.24 15 400 18.12 x 2.5 re 1 0.9 0.3 1.4 1.24 16 460 12.12 x 4 re 1 1 0.3 1.4 1.24 17.5 530 7.412 x 6 re 1 1 0.3 1.4 1.24 18.5 610 4.612 x 10 re 1 1 0.3 1.4 1.24 20 710 3.083 x 1.5 re 1 0.8 0.3 1.4 1.24 15.5 430 18.13 x 2.5 re 1 0.9 0.3 1.4 1.24 17 490 12.13 x 4 re 1 1 0.3 1.4 1.24 18 580 7.413 x 6 re 1 1 0.3 1.4 1.24 19.5 670 4.613 x 10 re 1 1 0.3 1.4 1.24 21.5 800 3.084 x 1.5 re 1 0.8 0.3 1.4 1.24 16 460 18.14 x 2.5 re 1 0.9 0.3 1.4 1.24 17.5 540 12.14 x 4 re 1 1 0.3 1.4 1.24 19 640 7.414 x 6 re 1 1 0.3 1.4 1.24 20.5 740 4.61

2 x 16 rm 7 1 0.3 4 x 0.8 1.4 22.5 790 1.912 x 25 rm/v 6 1.2 0.3 4 x 0.8 1.4 25.5 990 1.22 x 35 rm/v 6 1.2 0.3 4 x 0.8 1.4 27.5 1160 0.8682 x 50 rm/v 6 1.4 0.3 4 x 0.8 1.4 31 1460 0.6413 x 16 rm 7 1 0.3 4 x 0.8 1.4 23.5 870 1.914 x 10 re 1 1 0.3 4 x 0.8 1.4 21.5 730 3.084 x 16 re 7 1 0.3 4 x 0.8 1.4 25.5 990 1.913 x 25 sm 6 1.2 0.3 4 x 0.8 1.4 23.5 820 1.23 x 35 sm 6 1.2 0.3 4 x 0.8 1.4 25.5 960 0.8683 x 50 sm 6 1.4 0.3 4 x 0.8 1.56 29.5 1210 0.6413 x 70 sm 12 1.4 0.4 4 x 0.8 1.56 33 1500 0.4433 x 95 sm 15 1.6 0.4 4 x 0.8 1.56 37 1900 0.323 x 120 sm 15 1.6 0.4 4 x 0.8 1.72 39 2230 0.2533 x 150 sm 15 1.8 0.5 4 x 0.8 1.88 43 2650 0.2063 x 185 sm 30 2 0.5 4 x 0.8 1.88 47 3180 0.1643 x 240 sm 30 2.2 0.6 4 x 0.8 2.2 54 4070 0.1253 x 300 sm 30 2.4 0.6 4 x 0.8 2.36 60 4900 0.13 x 400 sm 53 2.6 0.7 4 x 0.8 2.52 66 6070 0.07783 x 500 sm 53 3 0.7 4 x 0.8 2.84 76 7620 0.0605

6 1.2/1.0 0.3 4 x 0.8 1.4 26 930 1.2

6 1.2/1.0 0.3 4 x 0.8 1.4 27 1060 0.868

6 1.4/1.2 0.3 4 x 0.8 1.56 31 1340 0.641

12 1.4/1.2 0.4 4 x 0.8 1.56 34 1690 0.443

15 1.6/1.4 0.4 4 x 0.8 1.56 39 2150 0.32

15 1.6/1.4 0.5 4 x 0.8 1.72 42 2570 0.253

15 1.8/1.4 0.5 4 x 0.8 1.88 47 3000 0.206

30 2.0/1.6 0.5 4 x 0.8 2.04 52 3700 0.164

Type AYFY Go to Top

3½ x 25/16 sm/rm

3½ x 35/16 sm/rm

3½ x 50/25 sm

3½ x 70/35 sm

3½ x 95/50 sm

3½ x 120/70 sm

3½ x 150/70 sm

3½ x 185/95 sm


30 2.2/1.6 0.6 4 x 0.8 2.2 58 4660 0.125

30 2.4/1.8 0.6 4 x 0.8 2.36 65 5630 0.1

53 2.6/2.0 0.7 4 x 0.8 2.68 72 6990 0.0778

53 3.0/2.2 0.7 4 x 0.8 2.84 82 8710 0.06054 x 25 sm 6 1.2 0.3 4 x 0.8 1.4 26 970 1.24 x 35 sm 6 1.2 0.3 4 x 0.8 1.4 28.5 1170 0.8684 x 50 sm 6 1.4 0.4 4 x 0.8 1.56 33 1510 0.641

2 x 1.5 re 1 0.8 0.3 1.8 11.5 165 12.1 14.53 x 1.5 re 1 0.8 0.3 1.8 12 190 12.1 14.54 x 1.5 re 1 0.8 0.3 1.8 13 220 12.1 14.55 x 1.5 re 1 0.8 0.3 1.8 14 255 12.1 14.56 x 1.5 re 1 0.8 0.3 1.8 15 300 12.1 14.57 x 1.5 re 1 0.8 0.3 1.8 15 310 12.1 14.510 x 1.5 re 1 0.8 0.3 1.8 18 430 12.1 14.512 x 1.5 re 1 0.8 0.3 1.8 18.5 465 12.1 14.514 x 1.5 re 1 0.8 0.3 1.8 18.5 445 12.1 14.516 x 1.5 re 1 0.8 0.3 1.8 19.5 500 12.1 14.519 x 1.5 re 1 0.8 0.3 2 21 590 12.1 14.524 x 1.5 re 1 0.8 0.3 2 24 740 12.1 14.527 x 1.5 re 1 0.8 0.3 2 24.5 800 12.1 14.530 x 1.5 re 1 0.8 0.3 2 25.5 870 12.1 14.537 x 1.5 re 1 0.8 0.3 2 27 1040 12.1 14.544 x 1.5 re 1 0.8 0.3 2 30.5 1230 12.1 14.552 x 1.5 re 1 0.8 0.4 2.2 33 1450 12.1 14.561 x 1.5 re 1 0.8 0.4 2.2 34 1660 12.1 14.52 x 2.5 re 1 0.9 0.3 1.8 13 215 7.41 8.873 x 2.5 re 1 0.9 0.3 1.8 13.5 250 7.41 8.874 x 2.5 re 1 0.9 0.3 1.8 14.5 290 7.41 8.875 x 2.5 re 1 0.9 0.3 1.8 15.5 350 7.41 8.876 x 2.5 re 1 0.9 0.3 1.8 17 405 7.41 8.877 x 2.5 re 1 0.9 0.3 1.8 17 425 7.41 8.8710 x 2.5 re 1 0.9 0.3 1.8 20.5 600 7.41 8.8712 x 2.5 re 1 0.9 0.3 2 21.5 680 7.41 8.8714 x 2.5 re 1 0.9 0.3 2 22 660 7.41 8.8716 x 2.5 re 1 0.9 0.3 2 23 750 7.41 8.8719 x 2.5 re 1 0.9 0.3 2 24 850 7.41 8.8724 x 2.5 re 1 0.9 0.3 2 28 1070 7.41 8.8727 x 2.5 re 1 0.9 0.3 2 28.5 1170 7.41 8.8730 x 2.5 re 1 0.9 0.3 2 29.5 1280 7.41 8.8737 x 2.5 re 1 0.9 0.4 2.2 33 1580 7.41 8.87

3½ x 240/120 sm

3½ x 300/150 sm

3½ x 400/185 sm

3½ x 500/240 sm

Table 4 : Unarmoured Control Cables type YY 650/1100 V Go to Top


Min. No. of wires (Cu)




Approx. OD (mm)



Approx. AC Resistance at Temp. 70º C (Ohm/km)


44 x 2.5 re 1 0.9 0.4 2.2 35 1860 7.41 8.8752 x 2.5 re 1 0.9 0.4 2.2 37 2130 7.41 8.8761 x 2.5 re 1 0.9 0.4 2.2 39 2460 7.41 8.87

2 x 1.5 re 1 0.8 0.3 1.4 1.24 15 415 12.13 x 1.5 re 1 0.8 0.3 1.4 1.24 15.5 455 12.14 x 1.5 re 1 0.8 0.3 1.4 1.24 16.5 495 12.15 x 1.5 re 1 0.8 0.3 1.4 1.24 17 560 12.16 x 1.5 re 1 0.8 0.3 1.4 1.24 18.5 620 12.17 x 1.5 re 1 0.8 0.3 1.4 1.24 18.5 630 12.110 x 1.5 re 1 0.8 0.3 1.4 1.4 20.5 740 12.1

12 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.24 19.5 640 12.114 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.4 21 730 12.116 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.4 21.5 790 12.119 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.4 22.5 880 12.124 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.4 25.5 1070 12.127 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.4 26 1160 12.130 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.4 27 1230 12.137 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.4 29 1420 12.144 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.56 33 1680 12.152 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.56 34 1920 12.161 x 1.5 re 1 0.8 0.3 4.0 x 0.8 1.56 36 2160 12.1

2 x 2.5 re 1 0.9 0.3 1.4 1.24 16.5 490 7.413 x 2.5 re 1 0.9 0.3 1.4 1.24 17 540 7.414 x 2.5 re 1 0.9 0.3 1.4 1.24 16 610 7.415 x 2.5 re 1 0.9 0.3 1.4 1.24 19 680 7.416 x 2.5 re 1 0.9 0.3 1.4 1.24 20 780 7.417 x 2.5 re 1 0.9 0.3 1.4 1.24 20 820 7.41

10 x 2.5 re 1 0.9 0.3 4.0 x 0.8 1.4 22 820 7.4112 x 2.5 re 1 0.9 0.3 4.0 x 0.8 1.4 22.5 880 7.4114 x 2.5 re 1 0.9 0.3 4.0 x 0.8 1.4 23.5 970 7.4116 x 2.5 re 1 0.9 0.3 4.0 x 0.8 1.4 24.5 1060 7.4119 x 2.5 re 1 0.9 0.3 4.0 x 0.8 1.4 25.5 1190 7.4124 x 2.5 re 1 0.9 0.3 4.0 x 0.8 1.4 29.5 1480 7.4127 x 2.5 re 1 0.9 0.3 4.0 x 0.8 1.4 30 1570 7.4130 x 2.5 re 1 0.9 0.3 4.0 x 0.8 1.56 32 1730 7.4137 x 2.5 re 1 0.9 0.4 4.0 x 0.8 1.56 34 2030 7.4144 x 2.5 re 1 0.9 0.4 4.0 x 0.8 1.56 37 2350 7.4152 x 2.5 re 1 0.9 0.4 4.0 x 0.8 1.56 38 2650 7.4161 x 2.5 re 1 0.9 0.4 4.0 x 0.8 1.56 40 3030 7.41

Table 5 Armoured Control cables type YWY and YFY 650/1100 V Go To Top


Min. No. of wires (Cu)



Armour Size (mm)


Approx. OD (mm)



YWY Go To Top

YFY Go To Top

YWY Go To Top

YFY Go To Top






These cables can be used on 3.3 kV (E) or (UE) systems

3 x 25 sm 6 2.3 0.3 4.0 x 0.8 1.4 28.5 1060 1.23 x 35 sm 6 2.3 0.3 4.0 x 0.8 1.56 31 1260 0.8683 x 50 sm 6 2.3 0.3 4.0 x 0.8 1.56 34 1470 0.6413 x 70 sm 12 2.3 0.3 4.0 x 0.8 1.56 37 1760 0.4433 x 95 sm 15 2.3 0.4 4.0 x 0.8 1.72 40 2140 0.323 x 120 sm 15 2.3 0.5 4.0 x 0.8 1.72 43 2460 0.2533 x 150 sm 15 2.3 0.5 4.0 x 0.8 1.88 45 2810 0.2063 x 185 sm 30 2.3 0.5 4.0 x 0.8 2.04 49 3300 0.1643 x 240 sm 30 2.3 0.6 4.0 x 0.8 2.2 54 4050 0.1253 x 300 sm 30 2.5 0.6 4.0 x 0.8 2.36 60 4890 0.13 x 400 sm 53 2.7 0.7 4.0 x 0.8 2.52 67 6030 0.07783 x 500 sm 53 3 0.7 4.0 x 0.8 2.84 76 7510 0.0605

3 x 25 sm 6 3.6 0.4 4.0 x 0.8 1.56 35 1530 1.23 x 35 sm 6 3.6 0.4 4.0 x 0.8 1.56 38 1740 0.8683 x 50 sm 6 3.6 0.4 4.0 x 0.8 1.72 41 2030 0.6413 x 70 sm 12 3.6 0.5 4.0 x 0.8 1.72 44 2370 0.4433 x 95 sm 15 3.6 0.5 4.0 x 0.8 1.88 47 2760 0.323 x 120 sm 15 3.6 0.5 4.0 x 0.8 1.88 49 3050 0.2533 x 150 sm 15 3.6 0.6 4.0 x 0.8 2.04 52 3450 0.2063 x 185 sm 30 3.6 0.6 4.0 x 0.8 2.2 56 4010 0.1643 x 240 sm 30 3.6 0.6 4.0 x 0.8 2.36 61 4800 0.1253 x 300 sm 30 3.6 0.7 4.0 x 0.8 2.52 66 5630 0.13 x 400 sm 53 3.6 0.7 4.0 x 0.8 2.68 72 6690 0.07783 x 500 sm 53 3.6 0.7 4.0 x 0.8 2.84 79 8020 0.0605

Cables of 6.35/11 kV grade (earthed system) are considered suitable for use on 6.6/6.6 kV (un-earthed system) also.

3 x 25 rm/v 6 4.2 0.5 4.0 x 0.8 1.72 46 2470 1.23 x 35 rm/v 6 4.2 0.5 4.0 x 0.8 1.88 49 2800 0.8683 x 50 rm/v 6 4.2 0.5 4.0 x 0.8 1.88 51 3060 0.641

Table 6 Armoured Three core Power cables type AYFY 1.9/3.3 kV Go To Top


Min. No. of wires (Al)



Flat wire Armour Size (mm)


Approx. OD (mm)



Table 7 Armoured Three Core Power cables type AYFY 3.8/6.6 kV (E) Go To Top







Approx. OD (mm)



Table 8 Armoured Three Core Power cables type AYCEFY 6.35/11 kV (E) Go To Top







Approx. OD (mm)






3 x 70 rm/v 12 4.2 0.5 4.0 x 0.8 2.04 55 3560 0.4433 x 95 rm/v 15 4.2 0.6 4.0 x 0.8 2.2 60 4160 0.323 x 120 rm/v 15 4.2 0.6 4.0 x 0.8 2.2 64 4710 0.2533 x 150 rm/v 15 4.2 0.6 4.0 x 0.8 2.36 67 5230 0.2063 x 185 rm/v 30 4.2 0.7 4.0 x 0.8 2.52 72 6090 0.1643 x 240 rm/v 30 4.2 0.7 4.0 x 0.8 2.68 78 7170 0.1253 x 300 rm/v 30 4.2 0.7 4.0 x 0.8 2.68 83 8120 0.13 x 400 rm/v 53 4.2 0.7 4.0 x 0.8 3 92 9670 0.07783 x 500 rm/v 53 4.2 0.7 4.0 x 0.8 3 99 11380 0.0605

Current Rating for 1 core Current Rating for 2 core

1.5 12.1 14.5 22 21 20 23 20 202.5 7.41 8.87 30 29 27 32 27 27

4 4.61 5.52 39 38 35 41 35 356 3.08 3.69 49 48 44 50 44 45

10 1.83 2.19 65 64 60 70 58 6016 1.15 1.38 85 83 82 90 75 7825 0.727 0.87 110 110 110 115 97 10535 0.524 0.627 130 125 130 140 120 12550 0.387 0.463 155 150 165 165 145 15570 0.268 0.321 190 175 20595 0.193 0.231 220 200 245

120 0.153 0.184 250 220 280150 0.124 0.149 280 245 320185 0.0991 0.12 305 260 370240 0.0754 0.0912 345 285 425300 0.0601 0.0739 375 310 475400 0.047 0.0592 400 335 550500 0.0366 0.0468 425 355 590630 0.0283 0.0379 470 375 660800 0.0221 0.0314 530 405 725

1000 0.0176 0.0271 590 435 870

General Construction

Conductors

Normally, aluminium conductors up to size 10 sq.mm are solid, circular in cross section, and sizes above 10 sq.mm are stranded. In case of single core and twin core cables, they are circular in cross section, while for 3 core and 4 core cables, conductors of cross section 25 sq.mm and above are normally sector shaped.

Insulation

The conductors are insulated with PVC base compound. Cables with heat resistant insulation are also available for maximum operating conductor temperature of 85º C for 1.1 kV cables. The insulation and outer sheathing compounds shall be conforming to IS 5831-1984.

Table 9 Data for Copper Power cables Go To Top

Conductor Cross Section

Max. DC Resistance at 20º C (Ohm/km)

Approx. AC Resistance at 70º C (Ohm/km)

In Ground (A)

In Duct (A)

In Air (A)

In Ground (A)

In Duct (A)

In Air (A)

General Notes and Legend Go To Top

The conductors of power cables are normally made from electrical purity aluminium and those of control cables are of annealed high conductivity copper. However, copper conductor power cables are also supplied against orders. All conductors confirm to IS 8130-1984.



Core Identification

Cores are identified by colour scheme of PVC insulation. The following colour scheme is adopted.

1 core - Red, Black, Yellow, Blue or Natural (non-pigmented)

2 core - Red and Black

3 core - Red, Yellow and Blue

4 core - Red, Yellow, Blue and Black (also 3½ Core) (Reduced neutral core is black)

5 core - Red, Yellow, Blue, Black and Grey

For cables having more than 5 cores : Two adjacent cores (counting and directional) in each layer are colored blue and yellow respectively and the remaining cores are grey.

Inner Sheath

For all cables having two or more cores, a common covering (inner sheath) is applied over the laid up cores either by extruded sheath of un-vulcanised rubber compound or wrapping of plastic or proofed tapes. Single core cables do not have inner sheath.

Armouring

For multi core cables, armouring is applied over the inner sheath. In case of cables where fictitious diameter over the inner sheath does not exceed 13 mm, the armour consist of galvanized round steel wires, above this size, normally the armour is of galvanized flat steel wires (strips). For single core armoured cables, non-magnetic armouring is provided over the insulation.

Outer Sheath

Outer sheath is extruded over the armouring. In case of multi core unarmoured cables, over the inner sheath, whereas in case of unarmoured single core cables, it is extruded over the insulation. This is always black in colour for best resistance to outdoor exposure.

Type Designation

Type designation of cables is based on the following alphabetical nomenclature.

A - Aluminium conductors - when first letter of type designation does not contain 'A' in the beginning, then cable is with copper conductors.

Y - When at first or second place in type designation, it stands for PVC insulation.

CE - Individual core screening

W - Round steel wire armouring

F - Flat steel wire (strip) armouring

Gb - Steel tape counter helix

Y - When last in type designation, it stands for PVC outer sheath.

WW - Steel double round wire armour

FF - Steel double strip armour.

Conductor Types

re - Circular, solid conductor

rm - Circular, stranded conductor (non-compacted)

rm/v - Circular, stranded compacted conductor

sm - Sector shaped, stranded conductor.

AYFY 3 x 400 sm 650/1100 V :- Aluminium conductor, PVC insulated, flat steel wire (Strip) armoured, PVC overall sheathed 3 core cable, conductor size 400 mm² stranded sector shaped 650/1100 V grade.

YY 37 x 1.5 re 650/1100 V :- Copper conductor, PVC insulated and PVC sheathed (unarmoured) 37 core cable, conductor size 1.5 mm² solid round 650/1100 V grade.

Current Ratings [based on IS 3961 (Part 2)]

The current ratings of cables given in the above tables are based on the normal conditions of installation described below.

For other conditions, the corresponding rating factors are to be applied.

Method of Installation

Single core cables

Laid direct in ground : Three in close trefoil formation or two touching in horizontal formation

In air : (1) Two single core cables installed one above the other fixed to a vertical wall as follows, the distance between the wall and the surface of the cable being 2.5 cm in each case.

Test Sequence of a typical 1.1 kV straight cable joint

Result

Number of cores, conductor cross section, voltage grade are written in the usual manner. For example,

Maximum conductor temperature - 70º C (for normal PVC)

Ambient air temperature - 40º C

Ground temperature - 30º C

Depth of laying (for cables laid direct in ground) - 75 cm (1.1 kV), 90 cm (3.3 to 11 kV)

Thermal resistivity of soil - 150º C cm/watt

Test Sequence

1. Insulation Resistance between conductor and grounded water bath

> 1000 Meg

Pass

2. Impact test for Straight joints only: Wedge shaped weight of 4 kgs dropped 6 times from a height of 2m (for armoured cables only)

No damage

3. AC voltage withstand 4 kV for 15 minutes (joints to be immersed in water)

No breakdown and no flashover

4. Impulse voltage withstand 10 positive and 10 negative, 1.2/50 micro secs, 8 kV peak between conductor and grounded water bath


5. Insulation resistance between conductor and grounded water bath

> 1000 Meg

6. Load cycling, 63 cycles, 5 hrs heating, 3 hrs cooling, conductor temperature PVC 75 deg C, XLPE 95 deg C

Pass

7. Thermal short circuit 1 sec symmetrical fault with conductor temperature as per cable specifications

No visible signs of damage

8. Load cycling, 63 cycles, 5 hrs heating, 3 hrs cooling, conductor temperature PVC 75 deg C, XLPE 95 deg C

9. Insulation resistance between conductor and grounded water bath

> 1000 Meg

10. Impulse voltage withstand 10 positive and 10 negative, 1.2/50 micro secs, 8 kV peak between conductor and grounded water bath


11. DC voltage withstand 15 kV for 5 minutes


Current RatingsDirect in ground In Duct In Air

36 31 33 30 32 27 0.30444 39 42 37 41 35 0.45659 51 56 51 56 47 0.7675 66 71 65 72 64 1.2297 86 93 84 99 84 1.9

120 100 110 100 120 105 2.66145 120 130 115 150 130 3.8170 140 155 135 185 155 5.32205 175 180 155 215 190 7.22230 195 200 170 240 220 9.12265 220 220 190 270 250 11.4300 240 240 210 305 290 14.1335 270 270 225 350 335 18.2370 295 295 245 395 380 22.8410 325 335 275 455 435 30.4435 345 355 295 490 480 38485 390 395 320 560 550 47.9530 440 415 345 640 600 60.8580 490 445 370 740 720 76

Current Rating

0.241 18 16 16 0.1140.204 25 21 21 0.190.198 32 27 27 0.3040.185 40 34 35 0.4560.176 55 45 47 0.76

0.16 70 58 59 1.220.157 90 76 78 1.90.154 110 92 99 2.660.154 135 115 125 3.80.107 16 14 13 0.1140.102 21 18 18 0.190.099 28 23 23 0.3040.093 35 30 30 0.4560.088 46 39 40 0.76

0.08 60 50 51 1.220.113 16 14 13 0.1140.108 21 18 18 0.190.105 28 23 23 0.304

Short Circuit Rating for 1 s kA(rms)

2 cable (A)

3 cable (A)

2 cable (A)

3 cable (A)

2 cable (A)

3 cable (A)

Approx. Reactance at 50 Hz Ohm/km

Short Circuit Rating for 1s kA(rms)

Direct in Ground In Duct In Air

0.099 35 30 30 0.4560.094 46 39 40 0.760.086 60 50 51 1.220.079 76 63 70 1.90.077 92 77 86 2.660.077 110 95 105 3.80.074 135 115 130 5.320.074 165 140 155 7.220.072 185 155 180 9.120.072 210 175 205 11.40.072 235 200 240 14.10.071 275 235 280 18.20.071 305 260 315 22.80.071 335 290 375 30.40.071 355 315 405 38

0.083 76 63 70 1.9

0.082 92 77 86 2.66

0.082 110 95 105 3.8

0.079 135 115 130 5.32

0.079 165 140 155 7.22

0.077 185 155 180 9.12

0.077 210 175 205 11.4

0.077 235 200 240 14.1

0.075 275 235 280 18.2

0.075 305 260 315 22.8

0.075 335 290 375 30.4

0.075 355 315 405 380.085 76 63 70 1.90.083 92 77 86 2.660.082 110 95 105 3.8

Current Rating


Approx. Reactan ce at 50 Hz (Ohm/km)

Approx. Capaci tance per phase µF/km

Short Circuit Rating for 1 second kA(rms)

Direct in Ground (A)

In Duct (A)

In Air (A)

21.7 0.239 0.165 18 16 16 0.11414.5 0.229 0.18 25 21 21 0.19

8.9 0.223 0.2 32 27 27 0.3045.54 0.207 0.22 40 34 35 0.456

3.7 0.198 0.25 55 45 47 0.7621.7 0.119 0.33 16 14 13 0.11414.5 0.115 0.355 21 18 18 0.19

8.9 0.112 0.395 28 23 23 0.3045.54 0.104 0.435 35 30 30 0.456

3.7 0.099 0.495 46 39 40 0.7621.7 0.127 0.33 16 14 13 0.11414.5 0.123 0.355 21 18 18 0.19

8.9 0.119 0.395 28 23 23 0.3045.54 0.112 0.435 35 30 30 0.456

2.3 0.179 0.28 70 58 59 1.221.44 0.176 0.31 90 76 78 1.91.04 0.173 0.33 110 92 99 2.660.77 0.173 0.35 135 115 125 3.8

2.3 0.09 0.56 60 50 51 1.223.7 0.107 0.495 46 39 40 0.762.3 0.097 0.56 60 50 51 1.22

1.44 0.088 0.62 76 63 70 1.91.04 0.086 0.66 92 77 86 2.660.77 0.086 0.7 110 95 105 3.8

0.532 0.083 0.73 135 115 130 5.320.385 0.083 0.76 165 140 155 7.220.305 0.082 0.78 185 155 180 9.120.249 0.082 0.795 210 175 205 11.40.199 0.082 0.81 235 200 240 14.10.152 0.079 0.82 275 235 280 18.20.123 0.079 0.825 305 260 315 22.8

0.0975 0.079 0.83 335 290 375 30.40.0767 0.079 1.1 355 315 405 38

1.44 0.094 0.62 76 63 70 1.9

1.04 0.093 0.66 92 77 86 2.66

0.77 0.093 0.7 110 95 105 3.8

0.532 0.09 0.73 135 115 130 5.32

0.384 0.09 0.76 165 140 155 7.22

0.305 0.088 0.78 185 155 180 9.12

0.249 0.088 0.795 210 175 205 11.4

0.199 0.088 0.81 235 200 240 14.1

0.152 0.085 0.82 275 235 280 18.2

0.123 0.085 0.825 305 260 315 22.8

0.0975 0.085 0.83 335 290 375 30.4

0.0767 0.085 1.1 355 315 405 381.44 0.097 0.62 76 63 70 1.91.04 0.094 0.66 92 77 86 2.660.77 0.093 0.7 110 95 105 3.8

Current Rating

0.218 0.1 23 20 20 0.1730.218 0.1 21 17 17 0.1730.218 0.1 21 17 17 0.1730.218 0.1 21 17 17 0.1730.218 0.1 15 13 13 0.1730.218 0.1 14 13 13 0.1730.218 0.1 13 11 11 0.1730.218 0.1 12 10 10 0.1730.218 0.1 11 10 10 0.1730.218 0.1 11 9 9 0.1730.218 0.1 10 9 9 0.1730.218 0.1 9 8 8 0.1730.218 0.1 9 8 8 0.1730.218 0.1 9 7 7 0.1730.218 0.1 8 7 7 0.1730.218 0.1 7 6 6 0.1730.218 0.1 7 6 6 0.1730.218 0.1 6 6 6 0.1730.208 0.1 32 27 27 0.2880.208 0.1 27 24 24 0.2880.208 0.1 27 24 24 0.2880.208 0.1 27 24 24 0.2880.208 0.1 21 18 18 0.2880.208 0.1 20 17 17 0.2880.208 0.1 18 15 15 0.2880.208 0.1 17 14 14 0.2880.208 0.1 16 13 13 0.2880.208 0.1 15 12 12 0.2880.208 0.1 14 12 12 0.2880.208 0.1 13 11 11 0.2880.208 0.1 12 10 10 0.2880.208 0.1 12 10 10 0.2880.208 0.1 11 9 9 0.288





In Duct (A)

In Air (A)

0.208 0.1 10 9 9 0.2880.208 0.1 10 8 8 0.2880.208 0.1 9 8 8 0.288

Current Rating

14.5 0.244 0.1 23 20 20 0.17314.5 0.244 0.1 21 17 17 0.17314.5 0.244 0.1 21 17 17 0.17314.5 0.244 0.1 21 17 17 0.17314.5 0.244 0.1 15 13 13 0.17314.5 0.244 0.1 14 13 13 0.17314.5 0.244 0.1 13 11 11 0.173

14.5 0.244 0.1 12 10 10 0.17314.5 0.244 0.1 11 10 10 0.17314.5 0.244 0.1 11 9 9 0.17314.5 0.244 0.1 10 9 9 0.17314.5 0.244 0.1 9 8 8 0.17314.5 0.244 0.1 9 8 8 0.17314.5 0.244 0.1 9 7 7 0.17314.5 0.244 0.1 8 7 7 0.17314.5 0.244 0.1 7 6 6 0.17314.5 0.244 0.1 7 6 6 0.17314.5 0.244 0.1 6 6 6 0.173

8.87 0.234 0.1 32 27 27 0.2888.87 0.234 0.1 27 24 24 0.2888.87 0.234 0.1 27 24 24 0.2888.87 0.234 0.1 27 24 24 0.2888.87 0.234 0.1 21 18 18 0.2888.87 0.234 0.1 20 17 17 0.288

8.87 0.234 0.1 18 15 15 0.2888.87 0.234 0.1 17 14 14 0.2888.87 0.234 0.1 16 13 13 0.2888.87 0.234 0.1 15 12 12 0.2888.87 0.234 0.1 14 12 12 0.2888.87 0.234 0.1 13 11 11 0.2888.87 0.234 0.1 12 10 10 0.2888.87 0.234 0.1 12 10 10 0.2888.87 0.234 0.1 11 9 9 0.2888.87 0.234 0.1 10 9 9 0.2888.87 0.234 0.1 10 8 8 0.2888.87 0.234 0.1 9 8 8 0.288






In Duct (A)

In Air (A)

Current Rating

1.44 0.104 0.445 74 61 70 1.91.04 0.1 0.5 89 75 86 2.660.77 0.096 0.555 105 92 105 3.8

0.532 0.091 0.63 130 110 130 5.320.385 0.088 0.715 160 135 155 7.220.305 0.086 0.785 180 150 180 9.120.249 0.084 0.99 205 170 205 11.40.199 0.083 1.08 230 195 240 14.10.152 0.081 1.21 265 230 280 18.20.123 0.08 1.23 295 250 315 22.8

0.0975 0.08 1.275 325 280 375 30.40.0767 0.08 1.29 345 305 405 38

Current Rating

1.44 0.119 0.34 74 61 70 1.91.04 0.113 0.375 89 75 86 2.660.77 0.108 0.415 105 92 105 3.8

0.532 0.103 0.47 130 110 130 5.320.385 0.098 0.52 160 135 155 7.220.305 0.095 0.565 180 150 180 9.120.249 0.093 0.72 205 170 205 11.40.199 0.09 0.775 230 195 240 14.10.152 0.088 0.86 265 230 280 18.20.123 0.086 0.94 295 250 315 22.8

0.0975 0.084 1.03 325 280 375 30.40.0767 0.082 1.125 345 305 405 38

Cables of 6.35/11 kV grade (earthed system) are considered suitable for use on 6.6/6.6 kV (un-earthed system) also.

Current Rating

1.44 0.139 0.436 73 61 73 1.91.04 0.132 0.48 86 72 87 2.660.77 0.126 0.525 100 86 105 3.8






In Duct (A)

In Air (A)






In Duct (A)

In Air (A)






In Duct (A)

In Air (A)

0.532 0.119 0.589 125 105 130 5.320.385 0.113 0.661 150 125 160 7.220.305 0.108 0.728 165 140 185 9.120.249 0.105 0.78 190 160 210 11.40.199 0.103 0.859 215 185 235 14.10.152 0.099 0.953 245 210 270 18.20.123 0.096 1.04 275 235 310 22.8

0.0975 0.093 1.17 315 275 365 30.40.0767 0.079 1.25 365 320 435 38

Current Rating for 3,3,5,4 core

21 17 17 0.17327 24 24 0.28836 30 30 0.4645 38 39 0.6960 50 52 1.1577 64 66 1.8499 81 90 2.88

120 99 110 4.03145 125 135 5.75175 150 165 8.05210 175 200 10.9240 195 230 13.8270 225 265 17.3300 255 305 21.3345 295 355 27.6385 335 400 34.5425 360 455 46440 390 500 57.5

72.592

115




In Ground (A)

In Duct (A)

In Air (A)


Cores are identified by colour scheme of PVC insulation. The following colour scheme is adopted.

4 core - Red, Yellow, Blue and Black (also 3½ Core) (Reduced neutral core is black)

For cables having more than 5 cores : Two adjacent cores (counting and directional) in each layer are colored blue and yellow respectively and the remaining cores are grey.




A - Aluminium conductors - when first letter of type designation does not contain 'A' in the beginning, then cable is with copper conductors.


YY 37 x 1.5 re 650/1100 V :- Copper conductor, PVC insulated and PVC sheathed (unarmoured) 37 core cable, conductor size 1.5 mm² solid round 650/1100 V grade.

The current ratings of cables given in the above tables are based on the normal conditions of installation described below.

Laid direct in ground : Three in close trefoil formation or two touching in horizontal formation

In air : (1) Two single core cables installed one above the other fixed to a vertical wall as follows, the distance between the wall and the surface of the cable being 2.5 cm in each case.

Number of cores, conductor cross section, voltage grade are written in the usual manner. For example,










For Aluminium conductor XLPE insulated, 11/11 kv (UE) 3 core

3Cx25 1.55 0.152 110 68.103Cx35 1.12 0.144 135 83.583Cx50 0.828 0.137 160 99.053Cx70 0.572 0.129 195 120.723Cx95 0.414 0.123 235 145.48

3Cx120 0.327 0.117 255 157.873Cx150 0.266 0.114 290 179.533Cx185 0.212 0.11 330 204.303Cx240 0.162 0.106 390 241.443Cx300 0.129 0.103 450 278.593Cx400 0.101 0.099 525 325.02

Conductor Cross-section

Approx. A.C Resistance at

oprating Temp. 90C. Ohm/km

Reactance at 50 HZ Ohm/km

Rating in Air (Amp)

Derated Capacity

(Amp)

For Aluminium conductor XLPE insulated, 3.3 kv (UE) 3 core

3Cx25 1.55 0.13 100 61.913Cx35 1.12 0.123 125 77.393Cx50 0.828 0.117 150 92.863Cx70 0.572 0.111 180 111.433Cx95 0.414 0.106 220 136.20

3Cx120 0.327 0.102 250 154.773Cx150 0.266 0.099 290 179.533Cx185 0.212 0.096 330 204.303Cx240 0.162 0.093 390 241.443Cx300 0.129 0.092 455 281.683Cx400 0.101 0.09 530 328.11



oprating Temp. 90C. Ohm/km

Reactance at 50 HZ for 6.6kV Ohm/km

Rating in Air (Amp)

Derated Capacity

(Amp)

SHORT CIRCUIT RATINGS OF CONDUCTOR

Short Circuit Rating for 1 Sec.Aluminium Copper

Sq.mm. kA(rms) kA(rms)3Cx25 2.35 3.583Cx35 3.29 53Cx50 4.7 7.153Cx70 6.58 10.013Cx95 8.93 13.58

3Cx120 11.3 17.163Cx150 14.1 21.453Cx185 17.4 26.453Cx225 21.15 32.183Cx240 22.6 34.323Cx300 28.2 42.93Cx400 37.6 57.23Cx500 47 71.53Cx630 59.2 90.13Cx800 75.2 114.4

3Cx1000 94 143


Conductor Temperature prior to Short Circuit : 90 0CMax. Short Circuit conductor Temperature : 250 0C

Table 1: D.C. Resistance and A.C. Resistance:Aluminium Copper

Sq.mm. Ohm/Km Ohm/Km Ohm/Km25 1.2 1.55 0.72735 0.868 1.12 0.52450 0.641 0.828 0.38770 0.443 0.572 0.26895 0.32 0.414 0.193120 0.253 0.327 0.153150 0.206 0.266 0.124185 0.164 0.212 0.0991225 0.134 0.173 0.0803240 0.125 0.162 0.0754300 0.1 0.129 0.0601400 0.0778 0.101 0.047500 0.0605 0.0782 0.0366630 0.0469 0.0606 0.0283800 0.0367 0.0474 0.02211000 0.0291 0.0376 0.0176

Table 2: APPROX. STAR CAPACITANCE : ( PER PHASE FOR AL & CU )

For 11 kV (UE) single coreSq.mm. mF/Km mF/Km mF/Km

25 0.235 0.195 0.14535 0.26 0.215 0.1650 0.285 0.235 0.17570 0.325 0.265 0.19595 0.37 0.3 0.215120 0.41 0.33 0.235150 0.44 0.355 0.255185 0.48 0.385 0.275240 0.54 0.435 0.305300 0.555 0.475 0.33400 0.575 0.53 0.37500 0.605 0.59 0.405630 0.68 0.66 0.455800 0.755 0.735 0.5051000 0.815 0.815 0.555

Conductor Crosssection

Max. D.C Resistance at

20 0C


oprating Temp. 90CMax. D.C Resistance at 20

C


For 6.6 kV (E) single core

For 11 kV (E) single core

Short Circuit Rating for 1 Sec.Aluminium Copper

Sq.mm. kA(rms) kA(rms)25 2.35 3.5835 3.29 550 4.7 7.1570 6.58 10.0195 8.93 13.58120 11.3 17.16150 14.1 21.45185 17.4 26.45225 21.15 32.18240 22.6 34.32300 28.2 42.9400 37.6 57.2500 47 71.5630 59.2 90.1800 75.2 114.41000 94 143

Table 4: APPROXIMATE REACTANCE AT 50 HZ

For 11 kV (UE) single coreSq.mm. Ohm/km Ohm/km Ohm/km

25 0.133 0.138 0.14935 0.126 0.131 0.14150 0.12 0.125 0.13470 0.113 0.118 0.12795 0.107 0.111 0.121120 0.103 0.107 0.115150 0.1 0.104 0.112185 0.098 0.101 0.108240 0.094 0.097 0.103300 0.092 0.094 0.101400 0.089 0.09 0.097500 0.088 0.088 0.094630 0.086 0.086 0.092800 0.084 0.085 0.0891000 0.082 0.083 0.087

Table 6: CURRENT RATINGS For AL 3 core 3 core 3.3 kV 3 core 6.6 kV

Table 3: SHORT CIRCUIT RATINGS OF CONDUCTOR


Conductor Temperature prior to Short Circuit : 90 0CMax. Short Circuit conductor Temperature : 250 0C


For 6.6 kV (E) single core

For 11 kV (E) single core

In air Direct in groundSq.mm. Amps. Amps. Amps.

25 95 100 9535 110 125 11050 130 150 13070 160 180 16095 190 220 190120 215 250 215150 245 290 240185 275 330 275240 320 390 315300 360 455 360400 410 530 410500 460 610 460

For AL Single core Single core 3.3 kV (E)

In air T.T.25 95 100 10535 115 120 13050 135 140 15570 165 170 19095 195 205 235120 225 230 275150 255 260 315185 285 295 360240 330 340 435300 375 385 505400 425 440 600500 485 500 695630 550 570 815800 625 640 9701000 690 720 1100

For CU 3 core 3 core 3.3 kV 3 core 6.6 kV

In air Direct in groundSq.mm. Amps. Amps. Amps.

25 120 125 12035 145 155 14550 170 185 17070 205 230 20595 245 280 245120 280 325 280


Direct in ground


Direct in ground T.T.

Direct in ground F.T.

Conductor

Cross-sectionDirect in ground

150 310 375 310185 350 425 350240 405 500 405300 455 575 455400 510 660 510

For CU Single core Single core 3.3 kV (E)

In air T.T.25 125 130 13535 150 155 16550 175 180 19570 215 220 25095 255 265 305120 290 300 355150 325 335 410185 365 375 465240 420 435 555300 475 490 645400 540 555 755500 605 625 865630 680 700 1000800 755 780 11701000 820 850 1305

The above Current Rating is based on following Operating Conditions :

Maximum continous operating conductor temperature = 90°C

Ambient air temperature = 40°C

Thermal Resistivity of soil = 150°C cm/watt

Depth of laying (for cables laid direct in ground) = 90 cms for cables upto 11kV (E) or (UE) grade and 105 cms for 22 kV and 33 kV grade cables

Method of Installation:

Three core cables install independently.

Table 5: Estimated Voltage Drop for XLPE, Aluminium Conductor, Armoured Three Core Cables Nominal Cross-

Voltage Drop V/kM/A


Direct in ground T.T.

Direct in ground F.T.

Standard ground temperature = 30°C

Single Core Cables: Three cables in a trefoil touching each other

sectional area Voltage Drop V/kM/A

of conductor 3.8/6.6 kV 11/11kV 16 4.24 - -25 2.67 2.67 2.6735 1.94 1.94 1.9450 1.44 1.44 1.4470 1 1 1.0195 0.7 0.74 0.74120 0.56 0.59 0.6150 0.48 0.49 0.49185 0.4 0.4 0.41240 0.3 0.32 0.33300 0.26 0.27 0.28400 0.21 0.23 0.24

Table 1: Rating factors for variation in ambient air temperature: Air Temperature - oC 20 25

Rating Factors 1.18 1.14

Table 2: Rating factors for variation in ground temperature: Air Temperature - oC 15 20

Rating Factors 1.12 1.08

Table 3: Rating factors for multicore cables laid on open racks in air :

No of racksNo. of cables per rack

1 2 31 1 0.98 0.962 1 0.95 0.933 1 0.94 0.926 1 0.93 0.9

Table 4: Rating factors for multicore cables laid on open racks in air :


1 2 31 1 0.84 0.82 1 0.8 0.763 1 0.78 0.74

6.6/6.6 & 6.35/11 kV

Conductor Temp. 90 oC

Conductor Temp. 90 oC

6 1 0.76 0.72


1 2 31 1 0.98 0.962 1 0.95 0.933 1 0.94 0.926 1 0.93 0.9

Table 6: Rating factors for grouping of multicore cables laid direct in ground, in horizontal formation:

SpacingNo. of cables per rack

2 3 4Cable touching 0.79 0.69 0.62

15 cm 0.82 0.72 0.6630 cm 0.86 0.76 0.72

SpacingFormation of cables

Cable touching 0.6 0.51 0.4315 cm 0.64 0.55 0.4630 cm 0.69 0.6 0.5

SpacingNo. of cables per rack

2 3 4Cable touching 0.78 0.68 0.61

15 cm 0.81 0.71 0.6530 cm 0.85 0.76 0.71

Table 9: Rating factors for depth of laying for Cables laid direct in the ground:

90 105 120Upto 11kV 1 0.99 0.98

22kV & 33kV - 1 0.99

Table 10: Rating factors for variation in thermal resistivity of soil Rating Factors for value of Thermal Resistivity of Soil in oC cm/Watt

100 120 150 2001.2 1.11 1 0.89

Table 5: Rating factors for single core cable in trefoil circuits laid on open racks in air:

Table 7: Rating factors for grouping of multicore cables laid direct in ground in tier formation :

Table 8: Rating factors for grouping of single core cable laid in trefoil circuits laid direct in ground in horizontal formation:

Depth of laying (cm)

V1' = 3444.827 V

V2 = V

1' - I

2 x Z

2 =

Z2 = 2.975* 6.84/100 =

0.2035 ohm

I2 = 669.4

A

Table 1: D.C. Resistance and A.C. Resistance:Copper

Ohm/Km0.9260.6680.4930.3410.2460.1950.1580.1260.1020.09610.07660.06

0.04660.0360.02810.0224

Table 2: APPROX. STAR CAPACITANCE : ( PER PHASE FOR AL & CU )

For 22 kv single coremF/Km mF/Km mF/Km mF/Km mF/Km mF/Km mF/Km

0.235 0.195 0.1450.15 0.26 0.215 0.16 0.150.165 0.125 0.285 0.235 0.175 0.165 0.1250.18 0.14 0.325 0.265 0.195 0.18 0.140.205 0.155 0.37 0.3 0.215 0.205 0.1550.22 0.17 0.41 0.33 0.235 0.22 0.170.235 0.18 0.44 0.355 0.255 0.235 0.180.255 0.19 0.48 0.385 0.275 0.255 0.190.285 0.21 0.54 0.435 0.305 0.285 0.210.31 0.23 0.555 0.475 0.33 0.31 0.230.345 0.25 0.575 0.53 0.37 0.345 0.250.38 0.275 0.605 0.59 0.405 0.380.42 0.305 00.465 0.3350.515 0.37

Approx. A.C Resistance at oprating Temp. 900C

For 33 kv single core

For 6.6 kV 3 core

For 11 kV 3 core

For 11 kv (UE) 3 core

For 22 kv 3 core

For 33 kv 3 core

Table 4: APPROXIMATE REACTANCE AT 50 HZ

For 22 kv single coreOhm/km Ohm/km Ohm/km Ohm/km Ohm/km Ohm/km Ohm/km

0.13 0.137 0.1520.143 0.123 0.13 0.144 0.1470.137 0.149 0.117 0.124 0.137 0.14 0.1560.129 0.14 0.111 0.117 0.129 0.132 0.1460.123 0.133 0.106 0.111 0.123 0.125 0.1390.117 0.127 0.102 0.107 0.117 0.12 0.1330.114 0.124 0.099 0.104 0.114 0.116 0.1280.11 0.12 0.096 0.101 0.11 0.113 0.1240.105 0.114 0.093 0.097 0.106 0.108 0.1190.102 0.111 0.092 0.095 0.103 0.105 0.1150.098 0.107 0.09 0.091 0.099 0.101 0.110.095 0.103 0.089 0.089 0.096 0.0970.092 0.10.091 0.0970.088 0.095

Table 6: CURRENT RATINGS For AL 3 core 3 core 6.6 kV 3 core 11 kV (E) 3 core 11 kV (UE) 3 core 22 kV

For 33 kv single core

For 6.6 kV 3 core

For 11 kV 3 core

For 11 kv (UE) 3 core

For 22 kv 3 core

For 33 kv 3 core

In air In air In air In airAmps. Amps. Amps. Amps. Amps. Amps. Amps.100 95 105 95 110120 110 125 110 135 110 135145 130 155 130 160 130 155180 160 180 160 195 160 190220 190 220 190 235 190 220255 215 255 215 255 210 255290 240 290 240 290 240 290330 275 330 275 330 270 330390 315 390 315 390 310 390450 360 450 355 450 350 445525 410 525 410 525 400 520610 460 610 460 610 450 600

For AL Single core Single core 3.3 kV (E) Single core 6.6 kV (E) Single core 11 kV (E)

In air F.T. In air T.T. In air F.T.110 95 100 105 115 95 100135 120 115 130 140 120 115165 135 135 155 170 135 135205 165 165 195 215 165 165255 200 200 240 260 195 200290 225 225 275 300 225 225335 250 225 320 345 250 255385 285 285 370 395 285 285460 330 330 440 470 330 330535 370 375 510 540 370 375630 425 425 600 645 425 425735 485 485 700 740 485 485855 550 550 815 855 550 5501015 625 620 965 1000 625 6201150 690 685 1095 1130 690 685

For CU 3 core 3 core 6.6 kV 3 core 11 kV (E) 3 core 11 kV (UE) 3 core 22 kV

In air In air In air In airAmps. Amps. Amps. Amps. Amps. Amps. Amps.130 120 135 120 140155 145 160 145 160 145 160185 170 190 170 190 165 190235 205 235 205 240 205 240285 245 285 245 290 240 290325 280 325 280 330 275 330

Direct in ground

Direct in ground

Direct in ground

Direct in ground

T.T.

Direct in ground

F.T.

Direct in ground

T.T.

Direct in ground

F.T.

Direct in ground

Direct in ground

Direct in ground

375 315 375 310 375 305 375420 350 425 350 425 345 425500 405 500 405 500 395 500570 455 570 455 570 445 570660 510 660 510 660 505 660

For CU Single core Single core 3.3 kV (E) Single core 6.6 kV (E) Single core 11 kV (E)

In air F.T. In air T.T. In air F.T.145 125 125 135 150 125 125175 150 150 165 185 150 150210 175 175 200 220 175 175265 215 215 250 275 215 215325 255 255 305 335 255 260375 290 290 360 390 290 295435 325 325 405 445 325 330495 365 365 460 505 365 370590 420 425 550 600 420 425680 475 475 635 695 475 480795 540 540 745 815 540 540915 610 605 865 915 605 6051055 680 675 990 1045 680 6751220 755 745 1140 1205 755 7501360 820 805 1270 1330 820 810

Depth of laying (for cables laid direct in ground) = 90 cms for cables upto 11kV (E) or (UE) grade and 105 cms for 22 kV and 33 kV grade cables

Table 5: Estimated Voltage Drop for XLPE, Aluminium Conductor, Armoured Three Core Cables

Voltage Drop V/kM/A

Direct in ground

T.T.

Direct in ground

F.T.

Direct in ground

T.T.

Direct in ground

F.T.

Voltage Drop V/kM/A

12.7/22kV 19/33 kV - -- -

1.94 -1.44 1.441.01 1.010.74 0.740.6 0.60.49 0.50.41 0.420.33 0.320.28 0.290.24 0.25

Table 1: Rating factors for variation in ambient air temperature: 30 35 40 45 50 55 60

1.1 1.05 1 0.95 0.89 0.84 0.78

Table 2: Rating factors for variation in ground temperature: 25 30 35 40 45 50

1.04 1 0.96 0.91 0.87 0.82

Table 3: Rating factors for multicore cables laid on open racks in air : No. of cables per rack

6 90.93 0.920.9 0.890.89 0.880.87 0.86

Table 4: Rating factors for multicore cables laid on open racks in air : No. of cables per rack

6 90.75 0.730.71 0.690.7 0.68

0.68 0.66

Table 6: Rating factors for grouping of multicore cables laid direct in ground, in horizontal formation: No. of cables per rack

6 8 100.54 0.5 0.460.59 0.54 0.510.65 0.62 0.59

No. of cables per rack6 8 10

0.53 0.48 0.450.57 0.53 0.50.64 0.6 0.58

Table 9: Rating factors for depth of laying for Cables laid direct in the ground:

1500.96 0.950.97 0.96

Table 10: Rating factors for variation in thermal resistivity of soil Rating Factors for value of Thermal Resistivity of Soil in oC cm/Watt

250 3000.8 0.73

Table 8: Rating factors for grouping of single core cable laid in trefoil circuits laid direct in ground in horizontal

180 or more

V2 = V

1' - I

2 x Z

2 =

Table 6: CURRENT RATINGS For AL 3 core 3 core 33 kV

In airAmps. Amps.

130 160160 200190 230215 270240 290270 350310 410350 450400 520

For AL Single core Single core 11 kV (E) Single core 11 kV (UE) Single core 22 kV (E)

In air T.T. In air F.T. In air T.T. In air F.T.105 115 95 100 110 120130 140 115 115 140 145 115 115155 170 135 140 165 175 135 135195 215 165 170 210 215 165 165240 260 200 200 250 265 185 195275 300 225 225 290 305 220 225320 345 250 255 330 350 250 250370 395 285 285 380 400 280 285440 470 330 330 450 470 325 330510 545 375 375 520 545 370 370600 645 425 430 610 640 420 425700 745 485 490 710 740 480 480815 855 555 550 820 865 545 545965 1000 630 620 965 1015 620 6151095 1130 695 685 1090 1115 685 680

For CU 3 core 3 core 33 kV

In airAmps. Amps.

165 195205 240245 290275 330

Direct in ground

Direct in ground

T.T.

Direct in ground

F.T.

Direct in ground

T.T.

Direct in ground

F.T.

Direct in ground

310 375345 425400 500450 570505 660

For CU Single core Single core 11 kV (E) Single core 11 kV (UE) Single core 22 kV (E)

In air T.T. In air F.T. In air T.T. In air F.T.140 150 125 125 145 155170 185 150 150 175 190 150 150205 220 175 175 210 225 175 175255 275 215 215 260 280 210 215315 335 255 260 320 340 250 255370 385 290 290 375 390 285 290410 445 325 330 420 450 325 325480 505 365 370 490 510 360 365575 600 425 425 580 605 415 420655 690 475 480 650 695 470 475750 805 540 540 755 810 535 535855 925 610 610 870 930 600 600990 1060 685 680 1000 1070 675 6651145 1180 765 750 1160 1205 750 7451270 1325 830 815 1290 1325 825 805

Direct in ground

T.T.

Direct in ground

F.T.

Direct in ground

T.T.

Direct in ground

F.T.

For AL Single core Single core 22 kV (E) Single core 33 kV (E)

In air T.T. In air F.T. In air T.T. In air F.T.

145 145165 175 135 135 170 180210 220 165 165 210 220255 265 195 200 260 270290 305 225 225 295 305335 355 250 250 340 350380 400 280 285 385 400450 470 325 330 465 475520 545 370 370 525 545615 640 425 425 615 640710 740 480 480 715 740830 855 550 550 830 865975 1015 625 620 980 10151110 1155 690 685 1110 1150

Direct in ground

T.T.

Direct in ground

F.T.

For CU Single core Single core 22 kV (E) Single core 33 kV (E)

In air T.T. In air F.T. In air T.T. In air F.T.

175 190215 225 175 180 215 230270 280 215 220 270 285320 340 255 265 325 345375 390 285 300 375 395425 455 325 325 430 455490 510 365 365 485 515565 605 420 420 475 610655 695 475 475 660 700775 810 540 540 785 815870 930 605 605 880 9351005 1070 685 680 1015 10751160 1210 765 755 1170 12151315 1340 830 820 1330 1345

Direct in ground

T.T.

Direct in ground

F.T.

Date post:	12-Jul-2016
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