⚡ 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

45 Amp Cable Size at 250 Meters (690V Three-Phase (Wind / Heavy Industrial))

IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 45 A over 250 m (820.2 ft).

Copper Cable (≤3% Drop)25 mm²Drop: 16.68V (2.42%)
Aluminum Cable (≤3% Drop)35 mm²Drop: 19.65V (2.85%)
Voltage at Load673.3 VLine Loss: 1300.0 W
Max Power & Breaker53.78 kW45A MCB/MCCB

IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 45A at 250m

Cross-Section (mm²)Cu AmpacityAl Ampacity Cu Voltage DropLoad VoltageAl Voltage DropPower LossStatus
1.5 mm²16 A12 A277.99 V (40.29%)412.0 V458.56 V (66.46%)21667.5 WDrop High
2.5 mm²24 A18 A166.8 V (24.17%)523.2 V275.14 V (39.87%)13000.5 WDrop High
4 mm²32 A25 A104.25 V (15.11%)585.8 V171.96 V (24.92%)8125.3 WDrop High
6 mm²41 A32 A69.5 V (10.07%)620.5 V114.64 V (16.61%)5416.9 WDrop High
10 mm²57 A44 A41.7 V (6.04%)648.3 V68.78 V (9.97%)3250.1 WDrop High
16 mm²76 A59 A26.06 V (3.78%)663.9 V42.99 V (6.23%)2031.3 W~ ≤5%
25 mm²101 A78 A16.68 V (2.42%)673.3 V27.51 V (3.99%)1300.0 W✓ OK (≤3%)
35 mm²125 A97 A11.91 V (1.73%)678.1 V19.65 V (2.85%)928.6 W✓ OK (≤3%)
50 mm²151 A118 A8.34 V (1.21%)681.7 V13.76 V (1.99%)650.0 W✓ OK (≤3%)
70 mm²192 A150 A5.96 V (0.86%)684.0 V9.83 V (1.42%)464.3 W✓ OK (≤3%)
95 mm²232 A181 A4.39 V (0.64%)685.6 V7.24 V (1.05%)342.1 W✓ OK (≤3%)
120 mm²269 A210 A3.47 V (0.5%)686.5 V5.73 V (0.83%)270.8 W✓ OK (≤3%)
150 mm²309 A241 A2.78 V (0.4%)687.2 V4.59 V (0.66%)216.7 W✓ OK (≤3%)
185 mm²353 A275 A2.25 V (0.33%)687.7 V3.72 V (0.54%)175.7 W✓ OK (≤3%)
240 mm²415 A324 A1.74 V (0.25%)688.3 V2.87 V (0.42%)135.4 W✓ OK (≤3%)
300 mm²477 A372 A1.39 V (0.2%)688.6 V2.29 V (0.33%)108.3 W✓ OK (≤3%)
400 mm²570 A445 A1.04 V (0.15%)689.0 V1.72 V (0.25%)81.3 W✓ OK (≤3%)

FAQ — 45 Amp Cable Size at 250 Meters (690V Three-Phase (Wind / Heavy Industrial))

What mm² cable size is required for 45A at 250 meters (690V)?

According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 25 mm² copper cable for 45A over 250m at 690V (voltage drop: 16.68V or 2.42%).

What is the power capacity of 45A at 690V?

At unity power factor, 45A at 690V supports 53.78 kW with a standard 45A circuit breaker.