Fire Resisting Cable

Fire Resisting Cables

Current Rating and Voltage Drop

Single Core Cables having PVC Insulation, Armoured (Copper Conductor) 600/1000V

Current-Carrying Capacities (Amp) PVC /AWA/PVC Cables
Conductor cross-sectional area (mm²) Reference Method 1 (Clipped direct) Reference Method 11 (on perforated cable tray) Reference Method 12 (free air) Direct in Ground In Single Way Ducts
3 or 4 cables 3-phase ac 2 cables dc spaced
2 cables single-phase ac or dc (Amp) 3 or 4 cables 3-phase ac (Amp) 2 cables single-phase ac flat & touching (Amp) 3 or 4 cables 3-phase ac flat & touching (Amp) Horizontal flat spaced (Amp) Vertical flat spaced (Amp) 3 cables trefoils (Amp) Horizontal (Amp) Vertical (Amp) 2 cables flat touching (Amp) 3 cables trefoil touching (Amp) 2 cables duct touching (Amp) 3 cables trefoil touching (Amp)
50 193 179 205 189 230 212 181 229 216 238 203 216 199
70 245 225 259 238 286 263 231 294 279 292 248 262 241
95 296 269 313 285 338 313 280 357 340 349 297 308 282
120 342 309 360 327 385 357 324 415 396 396 337 341 311
150 393 352 413 373 436 405 373 479 458 443 376 375 342
185 447 399 469 422 490 456 425 548 525 497 423 414 375
240 525 465 550 492 566 528 501 648 622 571 485 463 419
300 594 515 624 547 616 578 567 748 719 640 542 509 459
400 687 575 723 618 674 632 657 885 851 708 600 545 489
500 763 622 805 673 721 676 731 1035 997 780 660 585 523
630 843 669 891 728 771 723 809 1218 1174 856 721 632 563
800 919 710 976 777 824 772 886 1441 1390 895 756 662 587
1000 975 737 1041 808 872 816 945 1685 1627 939 797 703 621

Note: Rating factors for ambient temperature other than 30℃ please refer Table A

Rating factors for ground temperature other than 15℃ please refer Table B

Group Rating Factor please refer to Table F & Table G

Voltage Drop (Per Amp Per Meter) PVC/AWA/PVC Cables
Conductor cross-sectional area (mm²) 2 cables dc (mV/A/m) 2 cables-single-phase ac 3 or 4 cables-three-phase ac Direct in Ground Single Way Ducts
Reference Methods 1 & 11 (Touching) (mV/A/m) Reference Methods 12 (space*) (mV/A/m) Reference Methods 1, 11 & 12 (in trefoil touching) (mV/A/m) Reference Methods 1 & 11 (Flat touching) (mV/A/m) Reference Methods 12 (Flat spaced*) (mV/A/m) 2
cables flat touching (mV/A/m)
3
cables trefoil touching (mV/A/m)
2
cables flat touching (mV/A/m)

3
cables trefoil touching (mV/A/m)

r x z r x z r x z r x Z r x z
50 0.93 0.93 0.22 0.95 0.92 0.30 0.97 0.80 0.19 0.82 0.79 0.26 0.84 0.79 0.34 0.86 0.97 0.82 1.00

0.88

70 0.63 0.64 0.21 0.68 0.66 0.29 0.72 0.56 0.18 0.58 0.57 0.25 0.62 0.59 0.32 0.68 0.67 0.58 0.76

0.66

95 0.46 0.48 0.20 0.52 0.51 0.28 0.58 0.42 0.175 0.45 0.44 0.25 0.50 0.47 0.31 0.57 0.50 0.44 0.61

0.53

120 0.36 0.39 0.195 0.43 0.42 0.28 0.50 0.33 0.17 0.37 0.36 0.24 0.43 0.40 0.30 0.50 0.42 0.36 0.54

0.47

150 0.29 0.31 0.19 0.37 0.34 0.27 0.44 0.27 0.165 0.32 0.30 0.24 0.38 0.34 0.30 0.45 0.36 0.31 0.48

0.42

185 0.23 0.26 0.19 0.32 0.29 0.27 0.39 0.22 0.16 0.27 0.25 0.23 0.34 0.29 0.29 0.41 0.31 0.27 0.44

0.38

240 0.180 0.20 0.180 0.27 0.23 0.26 0.35 0.175 0.160 0.23 0.20 0.23 0.30 0.24 0.28 0.37 0.26 0.23 0.40

0.34

300 0.145 0.160 0.180 0.24 0.190 0.26 0.32 0.140 0.155 0.21 0.165 0.22 0.28 0.20 0.28 0.34 0.23 0.20 0.37

0.32

400 0.105 0.140 0.175 0.22 0.180 0.24 0.30 0.120 0.130 0.195 0.160 0.21 0.26 0.21 0.25 0.32 0.22 0.19 0.34

0.30

500 0.086 0.120 0.170 0.21 0.165 0.23 0.29 0.105 0.145 0.180 0.145 0.20 0.25 0.190 0.24 0.30 0.20 0.18 0.32

0.28

630 0.068 0.105 0.165 0.195 0.150 0.22 0.27 0.091 0.145 0.170 0.135 0.195 0.23 0.175 0.22 0.28 0.19 0.16 0.30

0.26

800 0.053 0.094 0.160 0.185 0.145 0.21 0.25 0.082 0.140 0.160 0.125 0.180 0.22 0.170 0.195 0.26 - - -

-

1000 0.042 0.095 0.155 0.185 0.140 0.190 0.24 0.079 0.135 0.155 0.125 0.165 0.21 0.165 0.170 0.24 - - -

-

Note: r=conductor resistance at operating temperature

Z=impedance, x=reactance

Table A: Rating Factors for Other Ambient Air Temperatures (PVC Insulated)

Ambient Temperature

25℃

30℃

35℃

40℃

45℃

50℃

55℃

60℃

65℃

70℃

Rating Factor

1.03

1.00

0.94

0.87

0.79

0.71

0.61

0.50

0.35

-

Table B: Rating Factors for Other Ground Temperatures (PVC Insulated)

Ground Temperature

10℃

15℃

20℃

25℃

30℃

35℃

40℃

45℃

50℃

Rating Factor

1.04

1.00

0.95

0.90

0.85

0.80

0.73

0.67

0.60

Table F: Group Rating Factors for Cables Installation

Group Rating Factors Number of Circuits
2 3 4 5 6 7 8 9 10 11 12
1 For circuits of 2 Single core cables laid flat touching horizontal formation, laid direct in ground 0.79 0.68 0.62 0.57 0.54 0.52 0.50 0.48 0.47 0.46 0.45
2 For circuits of 3 Single core cables in trefoil touching, laid direct in ground 0.78 0.66 0.61 0.56 0.53 0.50 0.49 0.47 0.46 0.44 0.43
  Number of Cables in a Group
2 3 4 5 6 7 8 9 10 11 12
3 For twin or multi-cores cables in horizontal formation, laid direct in ground Spaced 0.15m 0.87 0.78 0.74 0.70 0.68 0.66 0.64 0.63 0.62 0.61 0.60
Spaced 0.30m 0.91 0.84 0.81 0.78 0.77 0.75 0.75 0.74 0.73 0.73 0.72
      Number of Ducts in a Group
      2 3 4 5 6 7 8 9 10 11 12
4 For twin or multi-cores cables in single-way ducts horizontal formation spaced 0.30m apart 0.93 0.88 0.85 0.83 0.82 0.81 0.80 0.79 0.79 0.78 0.78
Table G Correction Factors for Groups of More than One Circuit of Single Core Cables, or More than One Multi-Cores Cable
Reference Methods of Installation Correction Factor (Cg)
  Number of Circuits or Multi-cores Cables
  2 3 4 5 6 7 8 9 10 12 14 16 18 20
Enclosed (Method 3 or 4) or bunched and clipped direct to a non-metallic surface (Method 1) 0.80 0.70 0.65 0.60 0.57 0.54 0.52 0.50 0.48 0.45 0.43 0.41 0.39 0.38
Single layer clipped to a non-metallic surface (Method 1) Touching 0.85 0.79 0.75 0.73 0.72 0.72 0.71 0.70 - - - - - -
Spaced* 0.94 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Single layer multi-cores on a perforated metal cable tray, vertical or horizontal(Method 11) Touching 0.86 0.81 0.77 0.75 0.74 0.73 0.73 0.72 0.71 0.70 - - - -
Spaced* 0.91 0.89 0.88 0.87 0.87 - - - - - - - - -
Single layer single core on a perforated metal cable tray, touching (Method 11) Horizontal 0.90 0.85 - - - - - - - - - - - -
Vertical 0.85 - - - - - - - - - - - - -
Single layer multi-cores touching on ladder supports (Method 13) 0.86 0.82 0.80 0.79 0.78 0.78 0.78 0.77 - - - - - -

*Space means a clearance between adjacent surfaces of at least one cable diameter (De). Where the horizontal clearance between adjacent cables exceeds 2 De, no correction factor need be applied.

Note: