40 Amp Cable Size at 250 Meters (415V Three-Phase (UK / Australia Industrial))
IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 40 A over 250 m (820.2 ft).
Copper Cable (≤3% Drop)35 mm²Drop: 10.59V (2.55%)
Aluminum Cable (≤3% Drop)50 mm²Drop: 12.23V (2.95%)
Voltage at Load404.4 VLine Loss: 733.7 W
Max Power & Breaker28.75 kW40A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 40A at 250m
| 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 | 247.11 V (59.54%) | 167.9 V | 407.61 V (98.22%) | 17120.0 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 148.26 V (35.73%) | 266.7 V | 244.57 V (58.93%) | 10272.0 W | Drop High |
| 4 mm² | 32 A | 25 A | 92.66 V (22.33%) | 322.3 V | 152.85 V (36.83%) | 6420.0 W | Drop High |
| 6 mm² | 41 A | 32 A | 61.78 V (14.89%) | 353.2 V | 101.9 V (24.55%) | 4280.0 W | Drop High |
| 10 mm² | 57 A | 44 A | 37.07 V (8.93%) | 377.9 V | 61.14 V (14.73%) | 2568.0 W | Drop High |
| 16 mm² | 76 A | 59 A | 23.17 V (5.58%) | 391.8 V | 38.21 V (9.21%) | 1605.0 W | Drop High |
| 25 mm² | 101 A | 78 A | 14.83 V (3.57%) | 400.2 V | 24.46 V (5.89%) | 1027.2 W | ~ ≤5% |
| 35 mm² | 125 A | 97 A | 10.59 V (2.55%) | 404.4 V | 17.47 V (4.21%) | 733.7 W | ✓ OK (≤3%) |
| 50 mm² | 151 A | 118 A | 7.41 V (1.79%) | 407.6 V | 12.23 V (2.95%) | 513.6 W | ✓ OK (≤3%) |
| 70 mm² | 192 A | 150 A | 5.3 V (1.28%) | 409.7 V | 8.73 V (2.1%) | 366.9 W | ✓ OK (≤3%) |
| 95 mm² | 232 A | 181 A | 3.9 V (0.94%) | 411.1 V | 6.44 V (1.55%) | 270.3 W | ✓ OK (≤3%) |
| 120 mm² | 269 A | 210 A | 3.09 V (0.74%) | 411.9 V | 5.1 V (1.23%) | 214.0 W | ✓ OK (≤3%) |
| 150 mm² | 309 A | 241 A | 2.47 V (0.6%) | 412.5 V | 4.08 V (0.98%) | 171.2 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 2.0 V (0.48%) | 413.0 V | 3.3 V (0.8%) | 138.8 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 1.54 V (0.37%) | 413.5 V | 2.55 V (0.61%) | 107.0 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 1.24 V (0.3%) | 413.8 V | 2.04 V (0.49%) | 85.6 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.93 V (0.22%) | 414.1 V | 1.53 V (0.37%) | 64.2 W | ✓ OK (≤3%) |
FAQ — 40 Amp Cable Size at 250 Meters (415V Three-Phase (UK / Australia Industrial))
What mm² cable size is required for 40A at 250 meters (415V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 35 mm² copper cable for 40A over 250m at 415V (voltage drop: 10.59V or 2.55%).
What is the power capacity of 40A at 415V?
At unity power factor, 40A at 415V supports 28.75 kW with a standard 40A circuit breaker.
Related Lengths & Currents (415V)
40A · 5m (415V)40A · 10m (415V)40A · 15m (415V)40A · 20m (415V)40A · 25m (415V)40A · 30m (415V)40A · 35m (415V)40A · 40m (415V)40A · 45m (415V)40A · 50m (415V)40A · 60m (415V)40A · 70m (415V)10A · 250m (415V)16A · 250m (415V)20A · 250m (415V)25A · 250m (415V)32A · 250m (415V)50A · 250m (415V)63A · 250m (415V)80A · 250m (415V)100A · 250m (415V)125A · 250m (415V)160A · 250m (415V)200A · 250m (415V)