125 Amp Cable Size at 25 Meters (415V Three-Phase (UK / Australia Industrial))
IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 125 A over 25 m (82.0 ft).
Copper Cable (≤3% Drop)35 mm²Drop: 3.31V (0.8%)
Aluminum Cable (≤3% Drop)70 mm²Drop: 2.73V (0.66%)
Voltage at Load411.7 VLine Loss: 716.5 W
Max Power & Breaker89.85 kW125A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 125A at 25m
| 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 | 77.22 V (18.61%) | 337.8 V | 127.38 V (30.69%) | 16718.8 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 46.33 V (11.16%) | 368.7 V | 76.43 V (18.42%) | 10031.2 W | Drop High |
| 4 mm² | 32 A | 25 A | 28.96 V (6.98%) | 386.0 V | 47.77 V (11.51%) | 6269.5 W | Drop High |
| 6 mm² | 41 A | 32 A | 19.31 V (4.65%) | 395.7 V | 31.84 V (7.67%) | 4179.7 W | Drop High |
| 10 mm² | 57 A | 44 A | 11.58 V (2.79%) | 403.4 V | 19.11 V (4.6%) | 2507.8 W | Drop High |
| 16 mm² | 76 A | 59 A | 7.24 V (1.74%) | 407.8 V | 11.94 V (2.88%) | 1567.4 W | Drop High |
| 25 mm² | 101 A | 78 A | 4.63 V (1.12%) | 410.4 V | 7.64 V (1.84%) | 1003.1 W | Drop High |
| 35 mm² | 125 A | 97 A | 3.31 V (0.8%) | 411.7 V | 5.46 V (1.32%) | 716.5 W | ✓ OK (≤3%) |
| 50 mm² | 151 A | 118 A | 2.32 V (0.56%) | 412.7 V | 3.82 V (0.92%) | 501.6 W | ✓ OK (≤3%) |
| 70 mm² | 192 A | 150 A | 1.65 V (0.4%) | 413.3 V | 2.73 V (0.66%) | 358.3 W | ✓ OK (≤3%) |
| 95 mm² | 232 A | 181 A | 1.22 V (0.29%) | 413.8 V | 2.01 V (0.48%) | 264.0 W | ✓ OK (≤3%) |
| 120 mm² | 269 A | 210 A | 0.97 V (0.23%) | 414.0 V | 1.59 V (0.38%) | 209.0 W | ✓ OK (≤3%) |
| 150 mm² | 309 A | 241 A | 0.77 V (0.19%) | 414.2 V | 1.27 V (0.31%) | 167.2 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 0.63 V (0.15%) | 414.4 V | 1.03 V (0.25%) | 135.6 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 0.48 V (0.12%) | 414.5 V | 0.8 V (0.19%) | 104.5 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 0.39 V (0.09%) | 414.6 V | 0.64 V (0.15%) | 83.6 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.29 V (0.07%) | 414.7 V | 0.48 V (0.12%) | 62.7 W | ✓ OK (≤3%) |
FAQ — 125 Amp Cable Size at 25 Meters (415V Three-Phase (UK / Australia Industrial))
What mm² cable size is required for 125A at 25 meters (415V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 35 mm² copper cable for 125A over 25m at 415V (voltage drop: 3.31V or 0.8%).
What is the power capacity of 125A at 415V?
At unity power factor, 125A at 415V supports 89.85 kW with a standard 125A circuit breaker.
Related Lengths & Currents (415V)
125A · 5m (415V)125A · 10m (415V)125A · 15m (415V)125A · 20m (415V)125A · 30m (415V)125A · 35m (415V)125A · 40m (415V)125A · 45m (415V)125A · 50m (415V)125A · 60m (415V)125A · 70m (415V)10A · 25m (415V)16A · 25m (415V)20A · 25m (415V)25A · 25m (415V)32A · 25m (415V)40A · 25m (415V)50A · 25m (415V)63A · 25m (415V)80A · 25m (415V)100A · 25m (415V)160A · 25m (415V)200A · 25m (415V)