Fire Resisting Cable

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Fire Resisting Cables

Current Rating and Voltage Drop

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

Current-Carrying Capacities (Amp) XLPE /AWA/PVC Cables
Size of Conductor Reference Method 1 (Clipped direct) Reference Method 11 (on perforated cable tray) Reference Method 12 (free air) In Single Way Ducts Laid Direct in Ground
2 cables 1-phase ac or dc flat & touching 3 or 4 cables 3-phase ac flat & touching 2 cables 1-phase ac or dc flat & touching 3 or 4 cables 3-phase ac flat & touching 3 or 4 cables 3-phase ac trefoil touching 2 cables 1-phase ac or dc ducts touching 3 or 4 cables 3-phase ac trefoil ducts touching 2 cables 1-phase ac or dc touching 3 or 4 cables 3-phase ac trefoiltouching
1 mm² 2 A 3 A 4 A 5 A 6 A 7 A 8 A 9 A 10 A
50 237 220 253 232 222 255 235 275 235
70 303 277 322 293 285 310 280 340 290
95 367 333 389 352 346 365 330 405 345
120 425 383 449 405 402 410 370 460 390
150 488 437 516 462 463 445 405 510 435
185 557 496 587 524 529 485 440 580 490
240 656 579 689 612 625 550 500 670 560
300 755 662 792 700 720 610 550 750 630
400 853 717 899 767 815 640 580 830 700
500 962 791 1016 851 918 690 620 910 770
630 1082 861 1146 935 1027 750 670 1000 840
800 1170 904 1246 987 1119 828 735 1117 931
1000 1261 961 1345 1055 1214 919 811 1254 1038

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

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

Group Rating Factor please refer to Table F & Table G

Voltage Drop (Per Amp Per Meter) XLPE/AWA/PVC Cables
Size of Conductor 2 Cables dc 2 Cables 1-phase ac 3 or 4 cables 3-phase ac 2 cables 1-phase ac 3 or 4 cables 3-phase ac touching
Reference Methods 1 & 11 (touching) Reference Methods 1, 11 & 12 (in trefoil touching) Reference Methods 1 & 11 (flat & touching) In ducts In ground In ducts In ground
1 mm² 2 mV/A/m 3 mV/A/m 4 mV/A/m 5 mV/A/m 6 mV/A/m 7 mV/A/m 8 mV/A/m 9 mV/A/m
    r x z r x z r x Z        
50 0.98 0.99 0.21 1.00 0.86 0.18 0.87 0.84 0.25 0.88 1.10 0.99 0.93 0.86
70 0.67 0.68 0.20 0.71 0.59 0.17 0.62 0.60 0.25 0.65 0.80 0.70 0.70 0.61
95 0.49 0.51 0.195 0.55 0.44 0.17 0.47 0.46 0.24 0.52 0.65 0.53 0.56 0.46
120 0.39 0.41 0.190 0.45 0.35 0.165 0.39 0.38 0.24 0.44 0.55 0.43 0.48 0.37
150 0.31 0.33 0.185 0.38 0.29 0.160 0.33 0.31 0.23 0.39 0.50 0.37 0.43 0.32
185 0.25 0.27 0.185 0.33 0.23 0.160 0.28 0.26 0.23 0.34 0.45 0.31 0.39 0.27
240 0.195 0.21 0.180 0.28 0.18 0.155 0.24 0.21 0.22 0.30 0.40 0.26 0.35 0.23
300 0.155 0.17 0.175 0.25 0.145 0.150 0.21 0.17 0.22 0.28 0.37 0.24 0.32 0.21
400 0.115 0.145 0.170 0.22 0.125 0.150 0.195 0.160 0.21 0.27 0.35 0.21 0.30 0.19
500 0.093 0.125 0.170 0.21 0.105 0.145 0.180 0.145 0.20 0.25 0.33 0.20 0.28 0.18
630 0.073 0.105 0.165 0.195 0.092 0.145 0.170 0.135 0.195 0.24 0.30 0.19 0.26 0.17
800 0.056 0.09 0.160 0.190 0.086 0.140 0.165 0.130 0.180 0.23 0.28 0.18 0.24 0.16
1000 0.045 0.092 0.155 0.180 0.080 0.135 0.155 0.125 0.17 0.21 0.26 0.17 0.22 0.15

Note: r=conductor resistance at operating temperature

Z=impedance, x=reactance

Table C: Rating Factors for Other Ambient Air Temperatures (XLPE Insulated)

Ambient Temperature 25℃ 30℃ 35℃ 40℃ 45℃ 50℃ 55℃ 60℃ 65℃ 70℃ 75℃ 80℃ 85℃
Rating Factor 1.02 1.00 0.96 0.91 0.87 0.82 0.76 0.71 0.65 0.58 0.50 0.41 0.29

Table D: Rating Factors for Other Ground Temperatures (XLPE Insulated)

Ground Temperature 15℃ 20℃ 25℃ 30℃ 35℃ 40℃ 45℃ 50℃
Rating Factor 1.00 0.97 0.93 0.89 0.86 0.82 0.77 0.73

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: