20 Amp Cable Size at 20 Meters (690V Three-Phase (Wind / Heavy Industrial))
IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 20 A over 20 m (65.6 ft).
Copper Cable (≤3% Drop)2.5 mm²Drop: 5.93V (0.86%)
Aluminum Cable (≤3% Drop)4 mm²Drop: 6.11V (0.89%)
Voltage at Load684.1 VLine Loss: 205.4 W
Max Power & Breaker23.9 kW20A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 20A 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 | 9.88 V (1.43%) | 680.1 V | 16.3 V (2.36%) | 342.4 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 5.93 V (0.86%) | 684.1 V | 9.78 V (1.42%) | 205.4 W | ✓ OK (≤3%) |
| 4 mm² | 32 A | 25 A | 3.71 V (0.54%) | 686.3 V | 6.11 V (0.89%) | 128.4 W | ✓ OK (≤3%) |
| 6 mm² | 41 A | 32 A | 2.47 V (0.36%) | 687.5 V | 4.08 V (0.59%) | 85.6 W | ✓ OK (≤3%) |
| 10 mm² | 57 A | 44 A | 1.48 V (0.21%) | 688.5 V | 2.45 V (0.35%) | 51.4 W | ✓ OK (≤3%) |
| 16 mm² | 76 A | 59 A | 0.93 V (0.13%) | 689.1 V | 1.53 V (0.22%) | 32.1 W | ✓ OK (≤3%) |
| 25 mm² | 101 A | 78 A | 0.59 V (0.09%) | 689.4 V | 0.98 V (0.14%) | 20.5 W | ✓ OK (≤3%) |
| 35 mm² | 125 A | 97 A | 0.42 V (0.06%) | 689.6 V | 0.7 V (0.1%) | 14.7 W | ✓ OK (≤3%) |
| 50 mm² | 151 A | 118 A | 0.3 V (0.04%) | 689.7 V | 0.49 V (0.07%) | 10.3 W | ✓ OK (≤3%) |
| 70 mm² | 192 A | 150 A | 0.21 V (0.03%) | 689.8 V | 0.35 V (0.05%) | 7.3 W | ✓ OK (≤3%) |
| 95 mm² | 232 A | 181 A | 0.16 V (0.02%) | 689.8 V | 0.26 V (0.04%) | 5.4 W | ✓ OK (≤3%) |
| 120 mm² | 269 A | 210 A | 0.12 V (0.02%) | 689.9 V | 0.2 V (0.03%) | 4.3 W | ✓ OK (≤3%) |
| 150 mm² | 309 A | 241 A | 0.1 V (0.01%) | 689.9 V | 0.16 V (0.02%) | 3.4 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 0.08 V (0.01%) | 689.9 V | 0.13 V (0.02%) | 2.8 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 0.06 V (0.01%) | 689.9 V | 0.1 V (0.01%) | 2.1 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 0.05 V (0.01%) | 690.0 V | 0.08 V (0.01%) | 1.7 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.04 V (0.01%) | 690.0 V | 0.06 V (0.01%) | 1.3 W | ✓ OK (≤3%) |
FAQ — 20 Amp Cable Size at 20 Meters (690V Three-Phase (Wind / Heavy Industrial))
What mm² cable size is required for 20A at 20 meters (690V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 2.5 mm² copper cable for 20A over 20m at 690V (voltage drop: 5.93V or 0.86%).
What is the power capacity of 20A at 690V?
At unity power factor, 20A at 690V supports 23.9 kW with a standard 20A circuit breaker.
Related Lengths & Currents (690V)
20A · 5m (690V)20A · 10m (690V)20A · 15m (690V)20A · 25m (690V)20A · 30m (690V)20A · 35m (690V)20A · 40m (690V)20A · 45m (690V)20A · 50m (690V)20A · 60m (690V)20A · 70m (690V)10A · 20m (690V)16A · 20m (690V)25A · 20m (690V)32A · 20m (690V)40A · 20m (690V)50A · 20m (690V)63A · 20m (690V)80A · 20m (690V)100A · 20m (690V)125A · 20m (690V)160A · 20m (690V)200A · 20m (690V)