125 Amp Cable Size at 20 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 20 m (65.6 ft).
Copper Cable (≤3% Drop)150 mm²Drop: 0.71V (2.97%)
Aluminum Cable (≤3% Drop)300 mm²Drop: 0.59V (2.45%)
Voltage at Load23.3 VLine Loss: 89.2 W
Max Power & Breaker3.0 kW125A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 125A at 20m
| Cross-Section (mm²) | Cu Ampacity | Al Ampacity | Cu Voltage Drop | Load Voltage | Al Voltage Drop | Power Loss | Status |
|---|---|---|---|---|---|---|---|
| 1.5 mm² | 16 A | 12 A | 71.33 V (297.22%) | 0.0 V | 117.67 V (490.28%) | 8916.7 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 42.8 V (178.33%) | 0.0 V | 70.6 V (294.17%) | 5350.0 W | Drop High |
| 4 mm² | 32 A | 25 A | 26.75 V (111.46%) | 0.0 V | 44.12 V (183.85%) | 3343.8 W | Drop High |
| 6 mm² | 41 A | 32 A | 17.83 V (74.31%) | 6.2 V | 29.42 V (122.57%) | 2229.2 W | Drop High |
| 10 mm² | 57 A | 44 A | 10.7 V (44.58%) | 13.3 V | 17.65 V (73.54%) | 1337.5 W | Drop High |
| 16 mm² | 76 A | 59 A | 6.69 V (27.86%) | 17.3 V | 11.03 V (45.96%) | 835.9 W | Drop High |
| 25 mm² | 101 A | 78 A | 4.28 V (17.83%) | 19.7 V | 7.06 V (29.42%) | 535.0 W | Drop High |
| 35 mm² | 125 A | 97 A | 3.06 V (12.74%) | 20.9 V | 5.04 V (21.01%) | 382.1 W | Drop High |
| 50 mm² | 151 A | 118 A | 2.14 V (8.92%) | 21.9 V | 3.53 V (14.71%) | 267.5 W | Drop High |
| 70 mm² | 192 A | 150 A | 1.53 V (6.37%) | 22.5 V | 2.52 V (10.51%) | 191.1 W | Drop High |
| 95 mm² | 232 A | 181 A | 1.13 V (4.69%) | 22.9 V | 1.86 V (7.74%) | 140.8 W | ~ ≤5% |
| 120 mm² | 269 A | 210 A | 0.89 V (3.72%) | 23.1 V | 1.47 V (6.13%) | 111.5 W | ~ ≤5% |
| 150 mm² | 309 A | 241 A | 0.71 V (2.97%) | 23.3 V | 1.18 V (4.9%) | 89.2 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 0.58 V (2.41%) | 23.4 V | 0.95 V (3.98%) | 72.3 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 0.45 V (1.86%) | 23.6 V | 0.74 V (3.06%) | 55.7 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 0.36 V (1.49%) | 23.6 V | 0.59 V (2.45%) | 44.6 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.27 V (1.11%) | 23.7 V | 0.44 V (1.84%) | 33.4 W | ✓ OK (≤3%) |
FAQ — 125 Amp Cable Size at 20 Meters (24V DC (Off-Grid Solar / Industrial Control))
What mm² cable size is required for 125A at 20 meters (24V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 150 mm² copper cable for 125A over 20m at 24V (voltage drop: 0.71V or 2.97%).
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.
Related Lengths & Currents (24V)
125A · 5m (24V)125A · 10m (24V)125A · 15m (24V)125A · 25m (24V)125A · 30m (24V)125A · 35m (24V)125A · 40m (24V)125A · 45m (24V)125A · 50m (24V)125A · 60m (24V)125A · 70m (24V)10A · 20m (24V)16A · 20m (24V)20A · 20m (24V)25A · 20m (24V)32A · 20m (24V)40A · 20m (24V)50A · 20m (24V)63A · 20m (24V)80A · 20m (24V)100A · 20m (24V)160A · 20m (24V)200A · 20m (24V)