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Cable Capacities
Current-carrying capacities (Iz) for common cable types from BS 7671 Appendix 4.
Singles in Conduit (PVC 70°C) — Table 4D1A
Singles in Conduit (PVC 70°C) — Table 4D1A
| Size (mm²) | 2-cable 1Φ Iz (A) | 3-cable 3Φ Iz (A) |
|---|---|---|
| 1.0 | 11.0 | 10.0 |
| 1.5 | 14.5 | 13.0 |
| 2.5 | 20.0 | 17.5 |
| 4.0 | 26.0 | 23.0 |
| 6.0 | 34.0 | 30.0 |
| 10.0 | 46.0 | 40.0 |
| 16.0 | 61.0 | 54.0 |
| 25.0 | 80.0 | 70.0 |
BS 7671: Table 4D1A
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Flat Twin & Earth (PVC 70°C) Clipped — Table 4D5A
Flat Twin & Earth (PVC 70°C) Clipped — Table 4D5A
| Size (mm²) | 2-cable 1Φ Iz (A) | 3-cable 3Φ Iz (A) |
|---|---|---|
| 1.0 | 15.5 | 13.5 |
| 1.5 | 20.0 | 17.5 |
| 2.5 | 27.0 | 24.0 |
| 4.0 | 37.0 | 32.0 |
| 6.0 | 47.0 | 41.0 |
| 10.0 | 64.0 | 57.0 |
| 16.0 | 85.0 | 76.0 |
BS 7671: Table 4D5A
SWA Cables (XLPE 90°C) — Table 4D4B
SWA Cables (XLPE 90°C) — Table 4D4B
| Size (mm²) | 2-cable 1Φ Iz (A) | 3-cable 3Φ Iz (A) |
|---|---|---|
| 1.5 | 25.0 | 21.0 |
| 2.5 | 33.0 | 28.0 |
| 4.0 | 43.0 | 37.0 |
| 6.0 | 55.0 | 47.0 |
| 10.0 | 74.0 | 64.0 |
| 16.0 | 97.0 | 84.0 |
| 25.0 | 127.0 | 110.0 |
| 35.0 | 155.0 | 134.0 |
BS 7671: Table 4D4B
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