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IEC 60228
Conductor Resistance
Maximum DC resistance of class 2 (stranded) conductors at 20 °C, and the value at your operating temperature using R = R20 · (1 + α (t − 20)). These are the values the Voltage Drop and Cable Sizing calculators use.
70 °C PVC, 90 °C XLPE
| Size (mm²) | Cu R20 (Ω/km) | Cu R70 (Ω/km) | Al R20 (Ω/km) | Al R70 (Ω/km) |
|---|---|---|---|---|
| 1.5 | 12.1000 | 14.4776 | – | – |
| 2.5 | 7.4100 | 8.8661 | – | – |
| 4 | 4.6100 | 5.5159 | – | – |
| 6 | 3.0800 | 3.6852 | – | – |
| 10 | 1.8300 | 2.1896 | – | – |
| 16 | 1.1500 | 1.3760 | 1.9100 | 2.2949 |
| 25 | 0.7270 | 0.8699 | 1.2000 | 1.4418 |
| 35 | 0.5240 | 0.6270 | 0.8680 | 1.0429 |
| 50 | 0.3870 | 0.4630 | 0.6410 | 0.7702 |
| 70 | 0.2680 | 0.3207 | 0.4430 | 0.5323 |
| 95 | 0.1930 | 0.2309 | 0.3200 | 0.3845 |
| 120 | 0.1530 | 0.1831 | 0.2530 | 0.3040 |
| 150 | 0.1240 | 0.1484 | 0.2060 | 0.2475 |
| 185 | 0.0991 | 0.1186 | 0.1640 | 0.1970 |
| 240 | 0.0754 | 0.0902 | 0.1250 | 0.1502 |
| 300 | 0.0601 | 0.0719 | 0.1000 | 0.1202 |
| 400 | 0.0470 | 0.0562 | – | – |
| 500 | 0.0366 | 0.0438 | – | – |
Source: IEC 60228 class 2 maximum DC resistance at 20 °C; α = 0.00393 /K (Cu), 0.00403 /K (Al). Verify against the edition that governs your project before design use.