400 Amp Cable Size at 20 Meters (415V Three-Phase (UK / Australia Industrial))
IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 400 A over 20 m (65.6 ft).
Copper Cable (≤3% Drop)240 mm²Drop: 1.24V (0.3%)
Aluminum Cable (≤3% Drop)400 mm²Drop: 1.22V (0.29%)
Voltage at Load413.8 VLine Loss: 856.0 W
Max Power & Breaker287.52 kW400A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 400A at 20m
| Cross-Section (mm²) | Cu Ampacity | Al Ampacity | Cu Voltage Drop | Load Voltage | Al Voltage Drop | Power Loss | Status |
|---|---|---|---|---|---|---|---|
| 1.5 mm² | 16 A | 12 A | 197.68 V (47.63%) | 217.3 V | 326.09 V (78.58%) | 136960.0 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 118.61 V (28.58%) | 296.4 V | 195.65 V (47.15%) | 82176.0 W | Drop High |
| 4 mm² | 32 A | 25 A | 74.13 V (17.86%) | 340.9 V | 122.28 V (29.47%) | 51360.0 W | Drop High |
| 6 mm² | 41 A | 32 A | 49.42 V (11.91%) | 365.6 V | 81.52 V (19.64%) | 34240.0 W | Drop High |
| 10 mm² | 57 A | 44 A | 29.65 V (7.15%) | 385.3 V | 48.91 V (11.79%) | 20544.0 W | Drop High |
| 16 mm² | 76 A | 59 A | 18.53 V (4.47%) | 396.5 V | 30.57 V (7.37%) | 12840.0 W | Drop High |
| 25 mm² | 101 A | 78 A | 11.86 V (2.86%) | 403.1 V | 19.57 V (4.71%) | 8217.6 W | Drop High |
| 35 mm² | 125 A | 97 A | 8.47 V (2.04%) | 406.5 V | 13.98 V (3.37%) | 5869.7 W | Drop High |
| 50 mm² | 151 A | 118 A | 5.93 V (1.43%) | 409.1 V | 9.78 V (2.36%) | 4108.8 W | Drop High |
| 70 mm² | 192 A | 150 A | 4.24 V (1.02%) | 410.8 V | 6.99 V (1.68%) | 2934.9 W | Drop High |
| 95 mm² | 232 A | 181 A | 3.12 V (0.75%) | 411.9 V | 5.15 V (1.24%) | 2162.5 W | Drop High |
| 120 mm² | 269 A | 210 A | 2.47 V (0.6%) | 412.5 V | 4.08 V (0.98%) | 1712.0 W | Drop High |
| 150 mm² | 309 A | 241 A | 1.98 V (0.48%) | 413.0 V | 3.26 V (0.79%) | 1369.6 W | Drop High |
| 185 mm² | 353 A | 275 A | 1.6 V (0.39%) | 413.4 V | 2.64 V (0.64%) | 1110.5 W | Drop High |
| 240 mm² | 415 A | 324 A | 1.24 V (0.3%) | 413.8 V | 2.04 V (0.49%) | 856.0 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 0.99 V (0.24%) | 414.0 V | 1.63 V (0.39%) | 684.8 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.74 V (0.18%) | 414.3 V | 1.22 V (0.29%) | 513.6 W | ✓ OK (≤3%) |
FAQ — 400 Amp Cable Size at 20 Meters (415V Three-Phase (UK / Australia Industrial))
What mm² cable size is required for 400A at 20 meters (415V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 240 mm² copper cable for 400A over 20m at 415V (voltage drop: 1.24V or 0.3%).
What is the power capacity of 400A at 415V?
At unity power factor, 400A at 415V supports 287.52 kW with a standard 400A circuit breaker.
Related Lengths & Currents (415V)
400A · 5m (415V)400A · 10m (415V)400A · 15m (415V)400A · 25m (415V)400A · 30m (415V)400A · 35m (415V)400A · 40m (415V)400A · 45m (415V)400A · 50m (415V)400A · 60m (415V)400A · 70m (415V)10A · 20m (415V)16A · 20m (415V)20A · 20m (415V)25A · 20m (415V)32A · 20m (415V)40A · 20m (415V)50A · 20m (415V)63A · 20m (415V)80A · 20m (415V)100A · 20m (415V)125A · 20m (415V)160A · 20m (415V)200A · 20m (415V)