30 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 30 A over 20 m (65.6 ft).
Copper Cable (≤3% Drop)50 mm²Drop: 0.51V (2.14%)
Aluminum Cable (≤3% Drop)70 mm²Drop: 0.61V (2.52%)
Voltage at Load23.5 VLine Loss: 15.4 W
Max Power & Breaker0.72 kW30A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 30A 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 | 17.12 V (71.33%) | 6.9 V | 28.24 V (117.67%) | 513.6 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 10.27 V (42.8%) | 13.7 V | 16.94 V (70.6%) | 308.2 W | Drop High |
| 4 mm² | 32 A | 25 A | 6.42 V (26.75%) | 17.6 V | 10.59 V (44.12%) | 192.6 W | Drop High |
| 6 mm² | 41 A | 32 A | 4.28 V (17.83%) | 19.7 V | 7.06 V (29.42%) | 128.4 W | Drop High |
| 10 mm² | 57 A | 44 A | 2.57 V (10.7%) | 21.4 V | 4.24 V (17.65%) | 77.0 W | Drop High |
| 16 mm² | 76 A | 59 A | 1.6 V (6.69%) | 22.4 V | 2.65 V (11.03%) | 48.1 W | Drop High |
| 25 mm² | 101 A | 78 A | 1.03 V (4.28%) | 23.0 V | 1.69 V (7.06%) | 30.8 W | ~ ≤5% |
| 35 mm² | 125 A | 97 A | 0.73 V (3.06%) | 23.3 V | 1.21 V (5.04%) | 22.0 W | ~ ≤5% |
| 50 mm² | 151 A | 118 A | 0.51 V (2.14%) | 23.5 V | 0.85 V (3.53%) | 15.4 W | ✓ OK (≤3%) |
| 70 mm² | 192 A | 150 A | 0.37 V (1.53%) | 23.6 V | 0.61 V (2.52%) | 11.0 W | ✓ OK (≤3%) |
| 95 mm² | 232 A | 181 A | 0.27 V (1.13%) | 23.7 V | 0.45 V (1.86%) | 8.1 W | ✓ OK (≤3%) |
| 120 mm² | 269 A | 210 A | 0.21 V (0.89%) | 23.8 V | 0.35 V (1.47%) | 6.4 W | ✓ OK (≤3%) |
| 150 mm² | 309 A | 241 A | 0.17 V (0.71%) | 23.8 V | 0.28 V (1.18%) | 5.1 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 0.14 V (0.58%) | 23.9 V | 0.23 V (0.95%) | 4.2 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 0.11 V (0.45%) | 23.9 V | 0.18 V (0.74%) | 3.2 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 0.09 V (0.36%) | 23.9 V | 0.14 V (0.59%) | 2.6 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.06 V (0.27%) | 23.9 V | 0.11 V (0.44%) | 1.9 W | ✓ OK (≤3%) |
FAQ — 30 Amp Cable Size at 20 Meters (24V DC (Off-Grid Solar / Industrial Control))
What mm² cable size is required for 30A at 20 meters (24V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 50 mm² copper cable for 30A over 20m at 24V (voltage drop: 0.51V or 2.14%).
What is the power capacity of 30A at 24V?
At unity power factor, 30A at 24V supports 0.72 kW with a standard 30A circuit breaker.
Related Lengths & Currents (24V)
30A · 5m (24V)30A · 10m (24V)30A · 15m (24V)30A · 25m (24V)30A · 30m (24V)30A · 35m (24V)30A · 40m (24V)30A · 45m (24V)30A · 50m (24V)30A · 60m (24V)30A · 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)125A · 20m (24V)160A · 20m (24V)200A · 20m (24V)