125 Amp Cable Size at 40 Meters (230V Single-Phase (IEC Europe / UK / AU))
IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 125 A over 40 m (131.2 ft).
Copper Cable (≤3% Drop)35 mm²Drop: 6.11V (2.66%)
Aluminum Cable (≤3% Drop)70 mm²Drop: 5.04V (2.19%)
Voltage at Load223.9 VLine Loss: 764.3 W
Max Power & Breaker28.75 kW125A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 125A at 40m
| 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 | 142.67 V (62.03%) | 87.3 V | 235.33 V (102.32%) | 17833.3 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 85.6 V (37.22%) | 144.4 V | 141.2 V (61.39%) | 10700.0 W | Drop High |
| 4 mm² | 32 A | 25 A | 53.5 V (23.26%) | 176.5 V | 88.25 V (38.37%) | 6687.5 W | Drop High |
| 6 mm² | 41 A | 32 A | 35.67 V (15.51%) | 194.3 V | 58.83 V (25.58%) | 4458.3 W | Drop High |
| 10 mm² | 57 A | 44 A | 21.4 V (9.3%) | 208.6 V | 35.3 V (15.35%) | 2675.0 W | Drop High |
| 16 mm² | 76 A | 59 A | 13.38 V (5.82%) | 216.6 V | 22.06 V (9.59%) | 1671.9 W | Drop High |
| 25 mm² | 101 A | 78 A | 8.56 V (3.72%) | 221.4 V | 14.12 V (6.14%) | 1070.0 W | Drop High |
| 35 mm² | 125 A | 97 A | 6.11 V (2.66%) | 223.9 V | 10.09 V (4.39%) | 764.3 W | ✓ OK (≤3%) |
| 50 mm² | 151 A | 118 A | 4.28 V (1.86%) | 225.7 V | 7.06 V (3.07%) | 535.0 W | ✓ OK (≤3%) |
| 70 mm² | 192 A | 150 A | 3.06 V (1.33%) | 226.9 V | 5.04 V (2.19%) | 382.1 W | ✓ OK (≤3%) |
| 95 mm² | 232 A | 181 A | 2.25 V (0.98%) | 227.7 V | 3.72 V (1.62%) | 281.6 W | ✓ OK (≤3%) |
| 120 mm² | 269 A | 210 A | 1.78 V (0.78%) | 228.2 V | 2.94 V (1.28%) | 222.9 W | ✓ OK (≤3%) |
| 150 mm² | 309 A | 241 A | 1.43 V (0.62%) | 228.6 V | 2.35 V (1.02%) | 178.3 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 1.16 V (0.5%) | 228.8 V | 1.91 V (0.83%) | 144.6 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 0.89 V (0.39%) | 229.1 V | 1.47 V (0.64%) | 111.5 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 0.71 V (0.31%) | 229.3 V | 1.18 V (0.51%) | 89.2 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.54 V (0.23%) | 229.5 V | 0.88 V (0.38%) | 66.9 W | ✓ OK (≤3%) |
FAQ — 125 Amp Cable Size at 40 Meters (230V Single-Phase (IEC Europe / UK / AU))
What mm² cable size is required for 125A at 40 meters (230V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 35 mm² copper cable for 125A over 40m at 230V (voltage drop: 6.11V or 2.66%).
What is the power capacity of 125A at 230V?
At unity power factor, 125A at 230V supports 28.75 kW with a standard 125A circuit breaker.
Related Lengths & Currents (230V)
125A · 5m (230V)125A · 10m (230V)125A · 15m (230V)125A · 20m (230V)125A · 25m (230V)125A · 30m (230V)125A · 35m (230V)125A · 45m (230V)125A · 50m (230V)125A · 60m (230V)125A · 70m (230V)10A · 40m (230V)16A · 40m (230V)20A · 40m (230V)25A · 40m (230V)32A · 40m (230V)40A · 40m (230V)50A · 40m (230V)63A · 40m (230V)80A · 40m (230V)100A · 40m (230V)160A · 40m (230V)200A · 40m (230V)