⚡ 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

50 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 50 A over 20 m (65.6 ft).

Copper Cable (≤3% Drop)10 mm²Drop: 3.71V (0.54%)
Aluminum Cable (≤3% Drop)16 mm²Drop: 3.82V (0.55%)
Voltage at Load686.3 VLine Loss: 321.0 W
Max Power & Breaker59.76 kW50A MCB/MCCB

IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 50A at 20m

Cross-Section (mm²)Cu AmpacityAl Ampacity Cu Voltage DropLoad VoltageAl Voltage DropPower LossStatus
1.5 mm²16 A12 A24.71 V (3.58%)665.3 V40.76 V (5.91%)2140.0 WDrop High
2.5 mm²24 A18 A14.83 V (2.15%)675.2 V24.46 V (3.54%)1284.0 WDrop High
4 mm²32 A25 A9.27 V (1.34%)680.7 V15.29 V (2.22%)802.5 WDrop High
6 mm²41 A32 A6.18 V (0.9%)683.8 V10.19 V (1.48%)535.0 WDrop High
10 mm²57 A44 A3.71 V (0.54%)686.3 V6.11 V (0.89%)321.0 W✓ OK (≤3%)
16 mm²76 A59 A2.32 V (0.34%)687.7 V3.82 V (0.55%)200.6 W✓ OK (≤3%)
25 mm²101 A78 A1.48 V (0.21%)688.5 V2.45 V (0.35%)128.4 W✓ OK (≤3%)
35 mm²125 A97 A1.06 V (0.15%)688.9 V1.75 V (0.25%)91.7 W✓ OK (≤3%)
50 mm²151 A118 A0.74 V (0.11%)689.3 V1.22 V (0.18%)64.2 W✓ OK (≤3%)
70 mm²192 A150 A0.53 V (0.08%)689.5 V0.87 V (0.13%)45.9 W✓ OK (≤3%)
95 mm²232 A181 A0.39 V (0.06%)689.6 V0.64 V (0.09%)33.8 W✓ OK (≤3%)
120 mm²269 A210 A0.31 V (0.04%)689.7 V0.51 V (0.07%)26.8 W✓ OK (≤3%)
150 mm²309 A241 A0.25 V (0.04%)689.8 V0.41 V (0.06%)21.4 W✓ OK (≤3%)
185 mm²353 A275 A0.2 V (0.03%)689.8 V0.33 V (0.05%)17.4 W✓ OK (≤3%)
240 mm²415 A324 A0.15 V (0.02%)689.8 V0.25 V (0.04%)13.4 W✓ OK (≤3%)
300 mm²477 A372 A0.12 V (0.02%)689.9 V0.2 V (0.03%)10.7 W✓ OK (≤3%)
400 mm²570 A445 A0.09 V (0.01%)689.9 V0.15 V (0.02%)8.0 W✓ OK (≤3%)

FAQ — 50 Amp Cable Size at 20 Meters (690V Three-Phase (Wind / Heavy Industrial))

What mm² cable size is required for 50A at 20 meters (690V)?

According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 10 mm² copper cable for 50A over 20m at 690V (voltage drop: 3.71V or 0.54%).

What is the power capacity of 50A at 690V?

At unity power factor, 50A at 690V supports 59.76 kW with a standard 50A circuit breaker.