300 Amp Cable Size at 20 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 20 m (65.6 ft).
Copper Cable (≤3% Drop)150 mm²Drop: 1.48V (0.21%)
Aluminum Cable (≤3% Drop)240 mm²Drop: 1.53V (0.22%)
Voltage at Load688.5 VLine Loss: 770.4 W
Max Power & Breaker358.53 kW300A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 300A at 20m
| 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 | 148.26 V (21.49%) | 541.7 V | 244.57 V (35.44%) | 77040.0 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 88.96 V (12.89%) | 601.0 V | 146.74 V (21.27%) | 46224.0 W | Drop High |
| 4 mm² | 32 A | 25 A | 55.6 V (8.06%) | 634.4 V | 91.71 V (13.29%) | 28890.0 W | Drop High |
| 6 mm² | 41 A | 32 A | 37.07 V (5.37%) | 652.9 V | 61.14 V (8.86%) | 19260.0 W | Drop High |
| 10 mm² | 57 A | 44 A | 22.24 V (3.22%) | 667.8 V | 36.68 V (5.32%) | 11556.0 W | Drop High |
| 16 mm² | 76 A | 59 A | 13.9 V (2.01%) | 676.1 V | 22.93 V (3.32%) | 7222.5 W | Drop High |
| 25 mm² | 101 A | 78 A | 8.9 V (1.29%) | 681.1 V | 14.67 V (2.13%) | 4622.4 W | Drop High |
| 35 mm² | 125 A | 97 A | 6.35 V (0.92%) | 683.6 V | 10.48 V (1.52%) | 3301.7 W | Drop High |
| 50 mm² | 151 A | 118 A | 4.45 V (0.64%) | 685.6 V | 7.34 V (1.06%) | 2311.2 W | Drop High |
| 70 mm² | 192 A | 150 A | 3.18 V (0.46%) | 686.8 V | 5.24 V (0.76%) | 1650.9 W | Drop High |
| 95 mm² | 232 A | 181 A | 2.34 V (0.34%) | 687.7 V | 3.86 V (0.56%) | 1216.4 W | Drop High |
| 120 mm² | 269 A | 210 A | 1.85 V (0.27%) | 688.1 V | 3.06 V (0.44%) | 963.0 W | Drop High |
| 150 mm² | 309 A | 241 A | 1.48 V (0.21%) | 688.5 V | 2.45 V (0.35%) | 770.4 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 1.2 V (0.17%) | 688.8 V | 1.98 V (0.29%) | 624.6 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 0.93 V (0.13%) | 689.1 V | 1.53 V (0.22%) | 481.5 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 0.74 V (0.11%) | 689.3 V | 1.22 V (0.18%) | 385.2 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.56 V (0.08%) | 689.4 V | 0.92 V (0.13%) | 288.9 W | ✓ OK (≤3%) |
FAQ — 300 Amp Cable Size at 20 Meters (690V Three-Phase (Wind / Heavy Industrial))
What mm² cable size is required for 300A at 20 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 20m at 690V (voltage drop: 1.48V or 0.21%).
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 · 25m (690V)300A · 30m (690V)300A · 35m (690V)300A · 40m (690V)300A · 45m (690V)300A · 50m (690V)300A · 60m (690V)300A · 70m (690V)10A · 20m (690V)16A · 20m (690V)20A · 20m (690V)25A · 20m (690V)32A · 20m (690V)40A · 20m (690V)50A · 20m (690V)63A · 20m (690V)80A · 20m (690V)100A · 20m (690V)125A · 20m (690V)160A · 20m (690V)200A · 20m (690V)