125 Amp Cable Size at 300 Meters (690V Three-Phase (Wind / Heavy Industrial))
IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 125 A over 300 m (984.3 ft).
Copper Cable (≤3% Drop)70 mm²Drop: 19.86V (2.88%)
Aluminum Cable (≤3% Drop)120 mm²Drop: 19.11V (2.77%)
Voltage at Load670.1 VLine Loss: 4299.1 W
Max Power & Breaker149.39 kW125A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 125A at 300m
| 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 | 926.65 V (134.3%) | 0.0 V | 1528.53 V (221.53%) | 200625.0 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 555.99 V (80.58%) | 134.0 V | 917.12 V (132.92%) | 120375.0 W | Drop High |
| 4 mm² | 32 A | 25 A | 347.49 V (50.36%) | 342.5 V | 573.2 V (83.07%) | 75234.4 W | Drop High |
| 6 mm² | 41 A | 32 A | 231.66 V (33.57%) | 458.3 V | 382.13 V (55.38%) | 50156.2 W | Drop High |
| 10 mm² | 57 A | 44 A | 139.0 V (20.14%) | 551.0 V | 229.28 V (33.23%) | 30093.8 W | Drop High |
| 16 mm² | 76 A | 59 A | 86.87 V (12.59%) | 603.1 V | 143.3 V (20.77%) | 18808.6 W | Drop High |
| 25 mm² | 101 A | 78 A | 55.6 V (8.06%) | 634.4 V | 91.71 V (13.29%) | 12037.5 W | Drop High |
| 35 mm² | 125 A | 97 A | 39.71 V (5.76%) | 650.3 V | 65.51 V (9.49%) | 8598.2 W | Drop High |
| 50 mm² | 151 A | 118 A | 27.8 V (4.03%) | 662.2 V | 45.86 V (6.65%) | 6018.7 W | ~ ≤5% |
| 70 mm² | 192 A | 150 A | 19.86 V (2.88%) | 670.1 V | 32.75 V (4.75%) | 4299.1 W | ✓ OK (≤3%) |
| 95 mm² | 232 A | 181 A | 14.63 V (2.12%) | 675.4 V | 24.13 V (3.5%) | 3167.8 W | ✓ OK (≤3%) |
| 120 mm² | 269 A | 210 A | 11.58 V (1.68%) | 678.4 V | 19.11 V (2.77%) | 2507.8 W | ✓ OK (≤3%) |
| 150 mm² | 309 A | 241 A | 9.27 V (1.34%) | 680.7 V | 15.29 V (2.22%) | 2006.2 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 7.51 V (1.09%) | 682.5 V | 12.39 V (1.8%) | 1626.7 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 5.79 V (0.84%) | 684.2 V | 9.55 V (1.38%) | 1253.9 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 4.63 V (0.67%) | 685.4 V | 7.64 V (1.11%) | 1003.1 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 3.47 V (0.5%) | 686.5 V | 5.73 V (0.83%) | 752.3 W | ✓ OK (≤3%) |
FAQ — 125 Amp Cable Size at 300 Meters (690V Three-Phase (Wind / Heavy Industrial))
What mm² cable size is required for 125A at 300 meters (690V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 70 mm² copper cable for 125A over 300m at 690V (voltage drop: 19.86V or 2.88%).
What is the power capacity of 125A at 690V?
At unity power factor, 125A at 690V supports 149.39 kW with a standard 125A circuit breaker.
Related Lengths & Currents (690V)
125A · 5m (690V)125A · 10m (690V)125A · 15m (690V)125A · 20m (690V)125A · 25m (690V)125A · 30m (690V)125A · 35m (690V)125A · 40m (690V)125A · 45m (690V)125A · 50m (690V)125A · 60m (690V)125A · 70m (690V)10A · 300m (690V)16A · 300m (690V)20A · 300m (690V)25A · 300m (690V)32A · 300m (690V)40A · 300m (690V)50A · 300m (690V)63A · 300m (690V)80A · 300m (690V)100A · 300m (690V)160A · 300m (690V)200A · 300m (690V)