⚡ 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

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

IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 20 A over 50 m (164.0 ft).

Copper Cable (≤3% Drop)2.5 mm²Drop: 14.83V (2.15%)
Aluminum Cable (≤3% Drop)4 mm²Drop: 15.29V (2.22%)
Voltage at Load675.2 VLine Loss: 513.6 W
Max Power & Breaker23.9 kW20A MCB/MCCB

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

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%)856.0 WDrop High
2.5 mm²24 A18 A14.83 V (2.15%)675.2 V24.46 V (3.54%)513.6 W✓ OK (≤3%)
4 mm²32 A25 A9.27 V (1.34%)680.7 V15.29 V (2.22%)321.0 W✓ OK (≤3%)
6 mm²41 A32 A6.18 V (0.9%)683.8 V10.19 V (1.48%)214.0 W✓ OK (≤3%)
10 mm²57 A44 A3.71 V (0.54%)686.3 V6.11 V (0.89%)128.4 W✓ OK (≤3%)
16 mm²76 A59 A2.32 V (0.34%)687.7 V3.82 V (0.55%)80.2 W✓ OK (≤3%)
25 mm²101 A78 A1.48 V (0.21%)688.5 V2.45 V (0.35%)51.4 W✓ OK (≤3%)
35 mm²125 A97 A1.06 V (0.15%)688.9 V1.75 V (0.25%)36.7 W✓ OK (≤3%)
50 mm²151 A118 A0.74 V (0.11%)689.3 V1.22 V (0.18%)25.7 W✓ OK (≤3%)
70 mm²192 A150 A0.53 V (0.08%)689.5 V0.87 V (0.13%)18.3 W✓ OK (≤3%)
95 mm²232 A181 A0.39 V (0.06%)689.6 V0.64 V (0.09%)13.5 W✓ OK (≤3%)
120 mm²269 A210 A0.31 V (0.04%)689.7 V0.51 V (0.07%)10.7 W✓ OK (≤3%)
150 mm²309 A241 A0.25 V (0.04%)689.8 V0.41 V (0.06%)8.6 W✓ OK (≤3%)
185 mm²353 A275 A0.2 V (0.03%)689.8 V0.33 V (0.05%)6.9 W✓ OK (≤3%)
240 mm²415 A324 A0.15 V (0.02%)689.8 V0.25 V (0.04%)5.3 W✓ OK (≤3%)
300 mm²477 A372 A0.12 V (0.02%)689.9 V0.2 V (0.03%)4.3 W✓ OK (≤3%)
400 mm²570 A445 A0.09 V (0.01%)689.9 V0.15 V (0.02%)3.2 W✓ OK (≤3%)

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

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

According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 2.5 mm² copper cable for 20A over 50m at 690V (voltage drop: 14.83V or 2.15%).

What is the power capacity of 20A at 690V?

At unity power factor, 20A at 690V supports 23.9 kW with a standard 20A circuit breaker.