⚡ Cu ρ (75°C): 0.0214 Ω·mm²/m 🔌 NEC / IEC Standards: NFPA 70 & IEC 60364 🇺🇸 US Grid Avg: $0.175/kWh 🇩🇪 DE Grid Avg: €0.345/kWh 🇸🇪 SE Elpris: 1.54 SEK/kWh 🇳🇴 NO Strøm: 1.17 NOK/kWh 🔩 Copper Ref: $9,650/t (2026-10-24)
⚡ IEC 60364-5-52 · DIN VDE · NEK 400 · SS 436 40 00

40 Amp Cable Size at 15 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 15 m (49.2 ft).

Copper Cable (≤3% Drop)6 mm²Drop: 3.71V (0.54%)
Aluminum Cable (≤3% Drop)10 mm²Drop: 3.67V (0.53%)
Voltage at Load686.3 VLine Loss: 256.8 W
Max Power & Breaker47.8 kW40A MCB/MCCB

IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 40A at 15m

Cross-Section (mm²)Cu AmpacityAl Ampacity Cu Voltage DropLoad VoltageAl Voltage DropPower LossStatus
1.5 mm²16 A12 A14.83 V (2.15%)675.2 V24.46 V (3.54%)1027.2 WDrop High
2.5 mm²24 A18 A8.9 V (1.29%)681.1 V14.67 V (2.13%)616.3 WDrop High
4 mm²32 A25 A5.56 V (0.81%)684.4 V9.17 V (1.33%)385.2 WDrop High
6 mm²41 A32 A3.71 V (0.54%)686.3 V6.11 V (0.89%)256.8 W✓ OK (≤3%)
10 mm²57 A44 A2.22 V (0.32%)687.8 V3.67 V (0.53%)154.1 W✓ OK (≤3%)
16 mm²76 A59 A1.39 V (0.2%)688.6 V2.29 V (0.33%)96.3 W✓ OK (≤3%)
25 mm²101 A78 A0.89 V (0.13%)689.1 V1.47 V (0.21%)61.6 W✓ OK (≤3%)
35 mm²125 A97 A0.64 V (0.09%)689.4 V1.05 V (0.15%)44.0 W✓ OK (≤3%)
50 mm²151 A118 A0.44 V (0.06%)689.6 V0.73 V (0.11%)30.8 W✓ OK (≤3%)
70 mm²192 A150 A0.32 V (0.05%)689.7 V0.52 V (0.08%)22.0 W✓ OK (≤3%)
95 mm²232 A181 A0.23 V (0.03%)689.8 V0.39 V (0.06%)16.2 W✓ OK (≤3%)
120 mm²269 A210 A0.19 V (0.03%)689.8 V0.31 V (0.04%)12.8 W✓ OK (≤3%)
150 mm²309 A241 A0.15 V (0.02%)689.9 V0.24 V (0.04%)10.3 W✓ OK (≤3%)
185 mm²353 A275 A0.12 V (0.02%)689.9 V0.2 V (0.03%)8.3 W✓ OK (≤3%)
240 mm²415 A324 A0.09 V (0.01%)689.9 V0.15 V (0.02%)6.4 W✓ OK (≤3%)
300 mm²477 A372 A0.07 V (0.01%)689.9 V0.12 V (0.02%)5.1 W✓ OK (≤3%)
400 mm²570 A445 A0.06 V (0.01%)689.9 V0.09 V (0.01%)3.9 W✓ OK (≤3%)

FAQ — 40 Amp Cable Size at 15 Meters (690V Three-Phase (Wind / Heavy Industrial))

What mm² cable size is required for 40A at 15 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 15m at 690V (voltage drop: 3.71V or 0.54%).

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.