Technical Information

Single Core Cables Copper Conductors

Current ratings for three phase and single phase circuits and volt drop at rated current. Single core PVC insulated unarmoured copper cables with or without sheath to BS6004 or BS6346.

Full thermal ratings: Ambient temperature 30°C Conductor operating temperature 70°C

Conductor Cross-Sectional Area Reference Method 4 (enclosed in conduit in thermally insulating wall etc) Reference Method 3 (Enclosed in conduit on a wall or in trunking etc) Reference Method 1 (clipped Direct) Reference Method 11 (on a perforated cable tray horizontal or vertical) Reference Method 12 (free air)
Horizontal Flat Spaced Vertical Flat Spaced Trefoil
2 Cables, single-phase AC or DC 3 or 4 Cables, three-phase AC 2 Cables, single-phase AC or DC 3 or 4 Cables Three-Phase AC 2 Cable single-phase Ac or DC Flat and Touching 3 or 4 Cables three-phase AC flat and touching or trefoil 2 Cables, single-phase AC or DC Flat and Touching 3 or 4 Cables three-phase AC Flat and touching 2 Cables, single-phase AC or DC or 3 cables three-phase AC 2 Cables, single-phase AC or DC or 3 cables three-phase AC 3 Cables trefoil three-phase AC
mm² A A A A A A A A A A A
1 11 10.5 13.5 12 15.5 14 - - - - -
1.5 14.5 13.5 17.5 15.5 20 18 - - - - -
2.5 19.5 18 24 21 27 25 - - - - -
4 26 24 32 28 37 33 - - - - -
6 34 31 41 36 47 43 - - - - -
10 46 42 57 50 65 59 - - - - -
16 61 56 76 68 87 79 - - - - -
25 80 73 101 89 114 104 126 112 146 130 110
35 99 89 125 110 141 129 156 141 181 162 137
50 119 108 151 134 182 167 191 172 219 197 167
70 151 136 192 171 234 214 246 223 281 254 216
95 182 164 232 207 284 261 300 273 341 311 264
120 210 188 269 239 330 303 349 318 396 362 308
150 240 216 300 262 381 349 404 369 456 419 356
185 273 245 341 296 436 400 463 424 521 480 409
240 320 286 400 346 515 472 549 504 615 569 485

VOLTAGE DROP (per ampre per metre):
Conductor operating temperature:70°C

Conductor Cross-Sectional Area 2 Cables DC 2 Cables, single-phase AC Reference Method 1 (clipped Direct)
Reference methods 3 & 4 (Enclosed in conduit etc. in or on a wall) Reference methods 1 & 11 (Clipped direct or on trays, touching) Reference method 12 (spaced*) Reference methods 3 & 4 (Enclosed in conduit etc. in or on a wall) Reference Methods 1, 11 & 12 (in trefoil) Reference methods 1 & 11 (flat and touching) Reference method 12 (Flat spaced*)
mm² mV/A/m mV/A/m mV/A/m mV/A/m mV/A/m mV/A/m mV/A/m mV/A/m
1 44 44 44 44 38 38 38 38
1.5 29 29 29 29 25 25 25 25
2.5 18 18 18 18 15 15 15 15
4 11 11 11 11 9.5 9.5 9.5 9.5
6 7.3 7.3 7.3 6.4 6.4 6.4 6.4 6.4
10 4.4 4.4 4.4 3.8 3.8 3.8 3.8 3.8
16 2.8 2.8 2.8 2.8 2.4 2.4 2.4 2.4
    r x z r x z r x z r x z r x z r x z r x z
25 1.75 1.80 0.33 1.80 1.75 0.20 1.75 1.75 0.29 1.80 1.50 0.29 1.55 1.50 0.175 1.50 1.50 0.25 1.55 1.50 0.32 1.55
35 1.25 1.30 0.31 1.30 1.25 0.195 1.25 1.25 0.28 1.30 1.10 0.27 1.10 1.10 0.170 1.10 1.10 0.24 1.10 1.10 0.32 1.15
50 0.93 0.95 0.30 1.00 0.93 0.190 0.95 0.93 0.28 0.97 0.81 0.26 0.85 0.80 0.165 0.82 0.80 0.24 0.84 0.80 0.32 0.86
70 0.63 0.65 0.29 0.72 0.63 0.185 0.66 0.63 0.27 0.69 0.56 0.25 0.61 0.55 0.160 0.57 0.55 0.24 0.60 0.55 0.31 0.63
95 0.46 0.49 0.28 0.56 0.47 0.180 0.50 0.47 0.27 0.54 0.42 0.24 0.48 0.41 0.155 0.43 0.41 0.23 0.47 0.40 0.31 0.51
120 0.36 0.39 0.27 0.47 0.37 0.175 0.41 0.37 0.26 0.45 0.33 0.23 0.41 0.32 0.150 0.36 0.32 0.23 0.40 0.32 0.30 0.44
150 0.29 0.31 0.27 0.41 0.30 0.175 0.34 0.29 0.26 0.39 0.27 0.23 0.36 0.26 0.150 0.30 0.26 0.23 0.34 0.26 0.30 0.40
185 0.23 0.25 0.27 0.37 0.24 0.170 0.29 0.24 0.26 0.35 0.22 0.23 0.32 0.21 0.145 0.26 0.21 0.22 0.31 0.21 0.30 0.36
240 0.180 0.195 0.26 0.33 0.185 0.165 0.25 0.185 0.25 0.31 0.17 0.23 0.29 0.160 0.145 0.22 0.160 0.22 0.27 0.160 0.29 0.34

Ambient Temperature Correction Factors

  For Rewireable Fuses Only with PVC Insulated Cable For all Other Protective Devices
Ambient Temperature °C 25 30 35 40 45 50 55 60 65 25 35 40 45 50 55 60 65
Correction Factor 1.03 1.00 0.97 0.94 0.91 0.87 0.84 0.69 0.48 1.03 0.94 0.87 0.79 0.71 0.61 0.50 0.35