⚡ 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

400 Amp Cable Size at 25 Meters (415V Three-Phase (UK / Australia Industrial))

IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 400 A over 25 m (82.0 ft).

Copper Cable (≤3% Drop)240 mm²Drop: 1.54V (0.37%)
Aluminum Cable (≤3% Drop)400 mm²Drop: 1.53V (0.37%)
Voltage at Load413.5 VLine Loss: 1070.0 W
Max Power & Breaker287.52 kW400A MCB/MCCB

IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 400A at 25m

Cross-Section (mm²)Cu AmpacityAl Ampacity Cu Voltage DropLoad VoltageAl Voltage DropPower LossStatus
1.5 mm²16 A12 A247.11 V (59.54%)167.9 V407.61 V (98.22%)171200.0 WDrop High
2.5 mm²24 A18 A148.26 V (35.73%)266.7 V244.57 V (58.93%)102720.0 WDrop High
4 mm²32 A25 A92.66 V (22.33%)322.3 V152.85 V (36.83%)64200.0 WDrop High
6 mm²41 A32 A61.78 V (14.89%)353.2 V101.9 V (24.55%)42800.0 WDrop High
10 mm²57 A44 A37.07 V (8.93%)377.9 V61.14 V (14.73%)25680.0 WDrop High
16 mm²76 A59 A23.17 V (5.58%)391.8 V38.21 V (9.21%)16050.0 WDrop High
25 mm²101 A78 A14.83 V (3.57%)400.2 V24.46 V (5.89%)10272.0 WDrop High
35 mm²125 A97 A10.59 V (2.55%)404.4 V17.47 V (4.21%)7337.1 WDrop High
50 mm²151 A118 A7.41 V (1.79%)407.6 V12.23 V (2.95%)5136.0 WDrop High
70 mm²192 A150 A5.3 V (1.28%)409.7 V8.73 V (2.1%)3668.6 WDrop High
95 mm²232 A181 A3.9 V (0.94%)411.1 V6.44 V (1.55%)2703.2 WDrop High
120 mm²269 A210 A3.09 V (0.74%)411.9 V5.1 V (1.23%)2140.0 WDrop High
150 mm²309 A241 A2.47 V (0.6%)412.5 V4.08 V (0.98%)1712.0 WDrop High
185 mm²353 A275 A2.0 V (0.48%)413.0 V3.3 V (0.8%)1388.1 WDrop High
240 mm²415 A324 A1.54 V (0.37%)413.5 V2.55 V (0.61%)1070.0 W✓ OK (≤3%)
300 mm²477 A372 A1.24 V (0.3%)413.8 V2.04 V (0.49%)856.0 W✓ OK (≤3%)
400 mm²570 A445 A0.93 V (0.22%)414.1 V1.53 V (0.37%)642.0 W✓ OK (≤3%)

FAQ — 400 Amp Cable Size at 25 Meters (415V Three-Phase (UK / Australia Industrial))

What mm² cable size is required for 400A at 25 meters (415V)?

According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 240 mm² copper cable for 400A over 25m at 415V (voltage drop: 1.54V or 0.37%).

What is the power capacity of 400A at 415V?

At unity power factor, 400A at 415V supports 287.52 kW with a standard 400A circuit breaker.