⚡ 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 50 Meters (24V DC (Off-Grid Solar / Industrial Control))

IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 125 A over 50 m (164.0 ft).

Copper Cable (≤3% Drop)400 mm²Drop: 0.67V (2.79%)
Aluminum Cable (≤3% Drop)400 mm²Drop: 1.1V (4.6%)
Voltage at Load23.3 VLine Loss: 83.6 W
Max Power & Breaker3.0 kW125A MCB/MCCB

IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 125A at 50m

Cross-Section (mm²)Cu AmpacityAl Ampacity Cu Voltage DropLoad VoltageAl Voltage DropPower LossStatus
1.5 mm²16 A12 A178.33 V (743.06%)0.0 V294.17 V (1225.69%)22291.7 WDrop High
2.5 mm²24 A18 A107.0 V (445.83%)0.0 V176.5 V (735.42%)13375.0 WDrop High
4 mm²32 A25 A66.87 V (278.65%)0.0 V110.31 V (459.64%)8359.4 WDrop High
6 mm²41 A32 A44.58 V (185.76%)0.0 V73.54 V (306.42%)5572.9 WDrop High
10 mm²57 A44 A26.75 V (111.46%)0.0 V44.12 V (183.85%)3343.7 WDrop High
16 mm²76 A59 A16.72 V (69.66%)7.3 V27.58 V (114.91%)2089.8 WDrop High
25 mm²101 A78 A10.7 V (44.58%)13.3 V17.65 V (73.54%)1337.5 WDrop High
35 mm²125 A97 A7.64 V (31.85%)16.4 V12.61 V (52.53%)955.4 WDrop High
50 mm²151 A118 A5.35 V (22.29%)18.7 V8.82 V (36.77%)668.7 WDrop High
70 mm²192 A150 A3.82 V (15.92%)20.2 V6.3 V (26.26%)477.7 WDrop High
95 mm²232 A181 A2.82 V (11.73%)21.2 V4.64 V (19.35%)352.0 WDrop High
120 mm²269 A210 A2.23 V (9.29%)21.8 V3.68 V (15.32%)278.6 WDrop High
150 mm²309 A241 A1.78 V (7.43%)22.2 V2.94 V (12.26%)222.9 WDrop High
185 mm²353 A275 A1.45 V (6.02%)22.6 V2.39 V (9.94%)180.7 WDrop High
240 mm²415 A324 A1.11 V (4.64%)22.9 V1.84 V (7.66%)139.3 W~ ≤5%
300 mm²477 A372 A0.89 V (3.72%)23.1 V1.47 V (6.13%)111.5 W~ ≤5%
400 mm²570 A445 A0.67 V (2.79%)23.3 V1.1 V (4.6%)83.6 W✓ OK (≤3%)

FAQ — 125 Amp Cable Size at 50 Meters (24V DC (Off-Grid Solar / Industrial Control))

What mm² cable size is required for 125A at 50 meters (24V)?

According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 400 mm² copper cable for 125A over 50m at 24V (voltage drop: 0.67V or 2.79%).

What is the power capacity of 125A at 24V?

At unity power factor, 125A at 24V supports 3.0 kW with a standard 125A circuit breaker.