300 Amp Cable Size at 120 Meters (690V Three-Phase (Wind / Heavy Industrial))
IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 300 A over 120 m (393.7 ft).
Copper Cable (≤3% Drop)150 mm²Drop: 8.9V (1.29%)
Aluminum Cable (≤3% Drop)240 mm²Drop: 9.17V (1.33%)
Voltage at Load681.1 VLine Loss: 4622.4 W
Max Power & Breaker358.53 kW300A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 300A at 120m
| 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 | 889.58 V (128.92%) | 0.0 V | 1467.39 V (212.67%) | 462240.0 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 533.75 V (77.35%) | 156.3 V | 880.44 V (127.6%) | 277344.0 W | Drop High |
| 4 mm² | 32 A | 25 A | 333.59 V (48.35%) | 356.4 V | 550.27 V (79.75%) | 173340.0 W | Drop High |
| 6 mm² | 41 A | 32 A | 222.4 V (32.23%) | 467.6 V | 366.85 V (53.17%) | 115560.0 W | Drop High |
| 10 mm² | 57 A | 44 A | 133.44 V (19.34%) | 556.6 V | 220.11 V (31.9%) | 69336.0 W | Drop High |
| 16 mm² | 76 A | 59 A | 83.4 V (12.09%) | 606.6 V | 137.57 V (19.94%) | 43335.0 W | Drop High |
| 25 mm² | 101 A | 78 A | 53.37 V (7.74%) | 636.6 V | 88.04 V (12.76%) | 27734.4 W | Drop High |
| 35 mm² | 125 A | 97 A | 38.12 V (5.53%) | 651.9 V | 62.89 V (9.11%) | 19810.3 W | Drop High |
| 50 mm² | 151 A | 118 A | 26.69 V (3.87%) | 663.3 V | 44.02 V (6.38%) | 13867.2 W | Drop High |
| 70 mm² | 192 A | 150 A | 19.06 V (2.76%) | 670.9 V | 31.44 V (4.56%) | 9905.1 W | Drop High |
| 95 mm² | 232 A | 181 A | 14.05 V (2.04%) | 676.0 V | 23.17 V (3.36%) | 7298.5 W | Drop High |
| 120 mm² | 269 A | 210 A | 11.12 V (1.61%) | 678.9 V | 18.34 V (2.66%) | 5778.0 W | Drop High |
| 150 mm² | 309 A | 241 A | 8.9 V (1.29%) | 681.1 V | 14.67 V (2.13%) | 4622.4 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 7.21 V (1.05%) | 682.8 V | 11.9 V (1.72%) | 3747.9 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 5.56 V (0.81%) | 684.4 V | 9.17 V (1.33%) | 2889.0 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 4.45 V (0.64%) | 685.6 V | 7.34 V (1.06%) | 2311.2 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 3.34 V (0.48%) | 686.7 V | 5.5 V (0.8%) | 1733.4 W | ✓ OK (≤3%) |
FAQ — 300 Amp Cable Size at 120 Meters (690V Three-Phase (Wind / Heavy Industrial))
What mm² cable size is required for 300A at 120 meters (690V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 150 mm² copper cable for 300A over 120m at 690V (voltage drop: 8.9V or 1.29%).
What is the power capacity of 300A at 690V?
At unity power factor, 300A at 690V supports 358.53 kW with a standard 300A circuit breaker.
Related Lengths & Currents (690V)
300A · 5m (690V)300A · 10m (690V)300A · 15m (690V)300A · 20m (690V)300A · 25m (690V)300A · 30m (690V)300A · 35m (690V)300A · 40m (690V)300A · 45m (690V)300A · 50m (690V)300A · 60m (690V)300A · 70m (690V)10A · 120m (690V)16A · 120m (690V)20A · 120m (690V)25A · 120m (690V)32A · 120m (690V)40A · 120m (690V)50A · 120m (690V)63A · 120m (690V)80A · 120m (690V)100A · 120m (690V)125A · 120m (690V)160A · 120m (690V)200A · 120m (690V)