⚡ 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

250 Amp Cable Size at 5 Meters (24V DC (Off-Grid Solar / Industrial Control))

IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 250 A over 5 m (16.4 ft).

Copper Cable (≤3% Drop)120 mm²Drop: 0.45V (1.86%)
Aluminum Cable (≤3% Drop)185 mm²Drop: 0.48V (1.99%)
Voltage at Load23.6 VLine Loss: 111.5 W
Max Power & Breaker6.0 kW250A MCB/MCCB

IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 250A at 5m

Cross-Section (mm²)Cu AmpacityAl Ampacity Cu Voltage DropLoad VoltageAl Voltage DropPower LossStatus
1.5 mm²16 A12 A35.67 V (148.61%)0.0 V58.83 V (245.14%)8916.7 WDrop High
2.5 mm²24 A18 A21.4 V (89.17%)2.6 V35.3 V (147.08%)5350.0 WDrop High
4 mm²32 A25 A13.38 V (55.73%)10.6 V22.06 V (91.93%)3343.8 WDrop High
6 mm²41 A32 A8.92 V (37.15%)15.1 V14.71 V (61.28%)2229.2 WDrop High
10 mm²57 A44 A5.35 V (22.29%)18.6 V8.82 V (36.77%)1337.5 WDrop High
16 mm²76 A59 A3.34 V (13.93%)20.7 V5.52 V (22.98%)835.9 WDrop High
25 mm²101 A78 A2.14 V (8.92%)21.9 V3.53 V (14.71%)535.0 WDrop High
35 mm²125 A97 A1.53 V (6.37%)22.5 V2.52 V (10.51%)382.1 WDrop High
50 mm²151 A118 A1.07 V (4.46%)22.9 V1.76 V (7.35%)267.5 WDrop High
70 mm²192 A150 A0.76 V (3.18%)23.2 V1.26 V (5.25%)191.1 WDrop High
95 mm²232 A181 A0.56 V (2.35%)23.4 V0.93 V (3.87%)140.8 WDrop High
120 mm²269 A210 A0.45 V (1.86%)23.6 V0.74 V (3.06%)111.5 W✓ OK (≤3%)
150 mm²309 A241 A0.36 V (1.49%)23.6 V0.59 V (2.45%)89.2 W✓ OK (≤3%)
185 mm²353 A275 A0.29 V (1.2%)23.7 V0.48 V (1.99%)72.3 W✓ OK (≤3%)
240 mm²415 A324 A0.22 V (0.93%)23.8 V0.37 V (1.53%)55.7 W✓ OK (≤3%)
300 mm²477 A372 A0.18 V (0.74%)23.8 V0.29 V (1.23%)44.6 W✓ OK (≤3%)
400 mm²570 A445 A0.13 V (0.56%)23.9 V0.22 V (0.92%)33.4 W✓ OK (≤3%)

FAQ — 250 Amp Cable Size at 5 Meters (24V DC (Off-Grid Solar / Industrial Control))

What mm² cable size is required for 250A at 5 meters (24V)?

According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 120 mm² copper cable for 250A over 5m at 24V (voltage drop: 0.45V or 1.86%).

What is the power capacity of 250A at 24V?

At unity power factor, 250A at 24V supports 6.0 kW with a standard 250A circuit breaker.