40 Amp Cable Size at 25 Meters (690V Three-Phase (Wind / Heavy Industrial))
IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 40 A over 25 m (82.0 ft).
Copper Cable (≤3% Drop)6 mm²Drop: 6.18V (0.9%)
Aluminum Cable (≤3% Drop)10 mm²Drop: 6.11V (0.89%)
Voltage at Load683.8 VLine Loss: 428.0 W
Max Power & Breaker47.8 kW40A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 40A 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 | 24.71 V (3.58%) | 665.3 V | 40.76 V (5.91%) | 1712.0 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 14.83 V (2.15%) | 675.2 V | 24.46 V (3.54%) | 1027.2 W | Drop High |
| 4 mm² | 32 A | 25 A | 9.27 V (1.34%) | 680.7 V | 15.29 V (2.22%) | 642.0 W | Drop High |
| 6 mm² | 41 A | 32 A | 6.18 V (0.9%) | 683.8 V | 10.19 V (1.48%) | 428.0 W | ✓ OK (≤3%) |
| 10 mm² | 57 A | 44 A | 3.71 V (0.54%) | 686.3 V | 6.11 V (0.89%) | 256.8 W | ✓ OK (≤3%) |
| 16 mm² | 76 A | 59 A | 2.32 V (0.34%) | 687.7 V | 3.82 V (0.55%) | 160.5 W | ✓ OK (≤3%) |
| 25 mm² | 101 A | 78 A | 1.48 V (0.21%) | 688.5 V | 2.45 V (0.35%) | 102.7 W | ✓ OK (≤3%) |
| 35 mm² | 125 A | 97 A | 1.06 V (0.15%) | 688.9 V | 1.75 V (0.25%) | 73.4 W | ✓ OK (≤3%) |
| 50 mm² | 151 A | 118 A | 0.74 V (0.11%) | 689.3 V | 1.22 V (0.18%) | 51.4 W | ✓ OK (≤3%) |
| 70 mm² | 192 A | 150 A | 0.53 V (0.08%) | 689.5 V | 0.87 V (0.13%) | 36.7 W | ✓ OK (≤3%) |
| 95 mm² | 232 A | 181 A | 0.39 V (0.06%) | 689.6 V | 0.64 V (0.09%) | 27.0 W | ✓ OK (≤3%) |
| 120 mm² | 269 A | 210 A | 0.31 V (0.04%) | 689.7 V | 0.51 V (0.07%) | 21.4 W | ✓ OK (≤3%) |
| 150 mm² | 309 A | 241 A | 0.25 V (0.04%) | 689.8 V | 0.41 V (0.06%) | 17.1 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 0.2 V (0.03%) | 689.8 V | 0.33 V (0.05%) | 13.9 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 0.15 V (0.02%) | 689.8 V | 0.25 V (0.04%) | 10.7 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 0.12 V (0.02%) | 689.9 V | 0.2 V (0.03%) | 8.6 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.09 V (0.01%) | 689.9 V | 0.15 V (0.02%) | 6.4 W | ✓ OK (≤3%) |
FAQ — 40 Amp Cable Size at 25 Meters (690V Three-Phase (Wind / Heavy Industrial))
What mm² cable size is required for 40A at 25 meters (690V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 6 mm² copper cable for 40A over 25m at 690V (voltage drop: 6.18V or 0.9%).
What is the power capacity of 40A at 690V?
At unity power factor, 40A at 690V supports 47.8 kW with a standard 40A circuit breaker.
Related Lengths & Currents (690V)
40A · 5m (690V)40A · 10m (690V)40A · 15m (690V)40A · 20m (690V)40A · 30m (690V)40A · 35m (690V)40A · 40m (690V)40A · 45m (690V)40A · 50m (690V)40A · 60m (690V)40A · 70m (690V)10A · 25m (690V)16A · 25m (690V)20A · 25m (690V)25A · 25m (690V)32A · 25m (690V)50A · 25m (690V)63A · 25m (690V)80A · 25m (690V)100A · 25m (690V)125A · 25m (690V)160A · 25m (690V)200A · 25m (690V)