⚡ 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

125 Amp Cable Size at 45 Meters (415V Three-Phase (UK / Australia Industrial))

IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 125 A over 45 m (147.6 ft).

Copper Cable (≤3% Drop)35 mm²Drop: 5.96V (1.44%)
Aluminum Cable (≤3% Drop)70 mm²Drop: 4.91V (1.18%)
Voltage at Load409.0 VLine Loss: 1289.7 W
Max Power & Breaker89.85 kW125A MCB/MCCB

IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 125A at 45m

Cross-Section (mm²)Cu AmpacityAl Ampacity Cu Voltage DropLoad VoltageAl Voltage DropPower LossStatus
1.5 mm²16 A12 A139.0 V (33.49%)276.0 V229.28 V (55.25%)30093.8 WDrop High
2.5 mm²24 A18 A83.4 V (20.1%)331.6 V137.57 V (33.15%)18056.2 WDrop High
4 mm²32 A25 A52.12 V (12.56%)362.9 V85.98 V (20.72%)11285.2 WDrop High
6 mm²41 A32 A34.75 V (8.37%)380.3 V57.32 V (13.81%)7523.4 WDrop High
10 mm²57 A44 A20.85 V (5.02%)394.2 V34.39 V (8.29%)4514.1 WDrop High
16 mm²76 A59 A13.03 V (3.14%)402.0 V21.5 V (5.18%)2821.3 WDrop High
25 mm²101 A78 A8.34 V (2.01%)406.7 V13.76 V (3.31%)1805.6 WDrop High
35 mm²125 A97 A5.96 V (1.44%)409.0 V9.83 V (2.37%)1289.7 W✓ OK (≤3%)
50 mm²151 A118 A4.17 V (1.0%)410.8 V6.88 V (1.66%)902.8 W✓ OK (≤3%)
70 mm²192 A150 A2.98 V (0.72%)412.0 V4.91 V (1.18%)644.9 W✓ OK (≤3%)
95 mm²232 A181 A2.19 V (0.53%)412.8 V3.62 V (0.87%)475.2 W✓ OK (≤3%)
120 mm²269 A210 A1.74 V (0.42%)413.3 V2.87 V (0.69%)376.2 W✓ OK (≤3%)
150 mm²309 A241 A1.39 V (0.33%)413.6 V2.29 V (0.55%)300.9 W✓ OK (≤3%)
185 mm²353 A275 A1.13 V (0.27%)413.9 V1.86 V (0.45%)244.0 W✓ OK (≤3%)
240 mm²415 A324 A0.87 V (0.21%)414.1 V1.43 V (0.35%)188.1 W✓ OK (≤3%)
300 mm²477 A372 A0.69 V (0.17%)414.3 V1.15 V (0.28%)150.5 W✓ OK (≤3%)
400 mm²570 A445 A0.52 V (0.13%)414.5 V0.86 V (0.21%)112.9 W✓ OK (≤3%)

FAQ — 125 Amp Cable Size at 45 Meters (415V Three-Phase (UK / Australia Industrial))

What mm² cable size is required for 125A at 45 meters (415V)?

According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 35 mm² copper cable for 125A over 45m at 415V (voltage drop: 5.96V or 1.44%).

What is the power capacity of 125A at 415V?

At unity power factor, 125A at 415V supports 89.85 kW with a standard 125A circuit breaker.