25 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 25 A over 20 m (65.6 ft).
Copper Cable (≤3% Drop)35 mm²Drop: 0.61V (2.55%)
Aluminum Cable (≤3% Drop)50 mm²Drop: 0.71V (2.94%)
Voltage at Load23.4 VLine Loss: 15.3 W
Max Power & Breaker0.6 kW25A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 25A 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 | 14.27 V (59.44%) | 9.7 V | 23.53 V (98.06%) | 356.7 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 8.56 V (35.67%) | 15.4 V | 14.12 V (58.83%) | 214.0 W | Drop High |
| 4 mm² | 32 A | 25 A | 5.35 V (22.29%) | 18.6 V | 8.82 V (36.77%) | 133.8 W | Drop High |
| 6 mm² | 41 A | 32 A | 3.57 V (14.86%) | 20.4 V | 5.88 V (24.51%) | 89.2 W | Drop High |
| 10 mm² | 57 A | 44 A | 2.14 V (8.92%) | 21.9 V | 3.53 V (14.71%) | 53.5 W | Drop High |
| 16 mm² | 76 A | 59 A | 1.34 V (5.57%) | 22.7 V | 2.21 V (9.19%) | 33.4 W | Drop High |
| 25 mm² | 101 A | 78 A | 0.86 V (3.57%) | 23.1 V | 1.41 V (5.88%) | 21.4 W | ~ ≤5% |
| 35 mm² | 125 A | 97 A | 0.61 V (2.55%) | 23.4 V | 1.01 V (4.2%) | 15.3 W | ✓ OK (≤3%) |
| 50 mm² | 151 A | 118 A | 0.43 V (1.78%) | 23.6 V | 0.71 V (2.94%) | 10.7 W | ✓ OK (≤3%) |
| 70 mm² | 192 A | 150 A | 0.31 V (1.27%) | 23.7 V | 0.5 V (2.1%) | 7.6 W | ✓ OK (≤3%) |
| 95 mm² | 232 A | 181 A | 0.23 V (0.94%) | 23.8 V | 0.37 V (1.55%) | 5.6 W | ✓ OK (≤3%) |
| 120 mm² | 269 A | 210 A | 0.18 V (0.74%) | 23.8 V | 0.29 V (1.23%) | 4.5 W | ✓ OK (≤3%) |
| 150 mm² | 309 A | 241 A | 0.14 V (0.59%) | 23.9 V | 0.24 V (0.98%) | 3.6 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 0.12 V (0.48%) | 23.9 V | 0.19 V (0.8%) | 2.9 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 0.09 V (0.37%) | 23.9 V | 0.15 V (0.61%) | 2.2 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 0.07 V (0.3%) | 23.9 V | 0.12 V (0.49%) | 1.8 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.05 V (0.22%) | 23.9 V | 0.09 V (0.37%) | 1.3 W | ✓ OK (≤3%) |
FAQ — 25 Amp Cable Size at 20 Meters (24V DC (Off-Grid Solar / Industrial Control))
What mm² cable size is required for 25A at 20 meters (24V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 35 mm² copper cable for 25A over 20m at 24V (voltage drop: 0.61V or 2.55%).
What is the power capacity of 25A at 24V?
At unity power factor, 25A at 24V supports 0.6 kW with a standard 25A circuit breaker.
Related Lengths & Currents (24V)
25A · 5m (24V)25A · 10m (24V)25A · 15m (24V)25A · 25m (24V)25A · 30m (24V)25A · 35m (24V)25A · 40m (24V)25A · 45m (24V)25A · 50m (24V)25A · 60m (24V)25A · 70m (24V)10A · 20m (24V)16A · 20m (24V)20A · 20m (24V)32A · 20m (24V)40A · 20m (24V)50A · 20m (24V)63A · 20m (24V)80A · 20m (24V)100A · 20m (24V)125A · 20m (24V)160A · 20m (24V)200A · 20m (24V)