Standard: BS 7671 Table 4E1A Single-core 90 °C thermosetting insulated cables, non armoured, with or without sheath Copper conductors Conductor temperature: 90 °C Ambient temperature: 30 °C Conductor nominal cross-sectional area [mm²] Current-carrying capacities in [A] Reference Method A (enclosed in conduit in thermally insulated wall etc.) Reference Method B (enclosed in conduit on a wall or in trunking etc.) Reference Method C (Clipped direct) Reference Method F (in free air or in perforated cable tray horizontal or vertical) Touching Spaced by one diameter 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 cables, single- phase AC or DC 3 or 4 cables, three- phase AC 2 cables, single-phase AC or DC flat 3 cables, three-phase AC flat 3 cables, three-phase AC trefoil 2 cables single-phase AC or DC or 3 cables three-phase AC flat Horizontal Vertical 1 2 3 4 5 6 7 8 9 10 11 1 2 3 4 5 6 7 8 9 10 11 12 1 14 13 17 15 19 17.5 – – – – – 1.5 19 17 23 20 25 23 – – – – – 2.5 26 23 31 28 34 31 – – – – – 4 35 31 42 37 46 41 – – – – – 6 45 40 54 48 59 54 – – – – – 10 61 54 75 66 81 74 – – – – – 16 81 73 100 88 109 99 – – – – – 25 106 95 133 117 143 130 161 141 135 182 161 35 131 117 164 144 176 161 200 176 169 226 201 50 158 141 198 175 228 209 242 216 207 275 246 70 200 179 253 222 293 268 310 279 268 353 318 95 241 216 306 269 355 326 377 342 328 430 389 120 278 249 354 312 413 379 437 400 383 500 454 150 318 285 393 342 476 436 504 464 444 577 527 185 362 324 449 384 545 500 575 533 510 661 605 240 424 380 528 450 644 590 679 634 607 781 719 300 486 435 603 514 743 681 783 736 703 902 833 400 – – 683 584 868 793 940 868 823 1085 1008 500 – – 783 666 990 904 1083 998 946 1253 1169 630 – – 900 764 1130 1033 1254 1151 1088 1454 1362 800 – – – – 1288 1179 1358 1275 1214 1581 1485 1000 – – – – 1443 1323 1520 1436 1349 1775 1671