20 Amp Cable Size at 70 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 70 m (229.7 ft).
Copper Cable (≤3% Drop)4 mm²Drop: 12.97V (1.88%)
Aluminum Cable (≤3% Drop)6 mm²Drop: 14.27V (2.07%)
Voltage at Load677.0 VLine Loss: 449.4 W
Max Power & Breaker23.9 kW20A MCB/MCCB
IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 20A at 70m
| 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 | 34.59 V (5.01%) | 655.4 V | 57.07 V (8.27%) | 1198.4 W | Drop High |
| 2.5 mm² | 24 A | 18 A | 20.76 V (3.01%) | 669.2 V | 34.24 V (4.96%) | 719.0 W | ~ ≤5% |
| 4 mm² | 32 A | 25 A | 12.97 V (1.88%) | 677.0 V | 21.4 V (3.1%) | 449.4 W | ✓ OK (≤3%) |
| 6 mm² | 41 A | 32 A | 8.65 V (1.25%) | 681.4 V | 14.27 V (2.07%) | 299.6 W | ✓ OK (≤3%) |
| 10 mm² | 57 A | 44 A | 5.19 V (0.75%) | 684.8 V | 8.56 V (1.24%) | 179.8 W | ✓ OK (≤3%) |
| 16 mm² | 76 A | 59 A | 3.24 V (0.47%) | 686.8 V | 5.35 V (0.78%) | 112.3 W | ✓ OK (≤3%) |
| 25 mm² | 101 A | 78 A | 2.08 V (0.3%) | 687.9 V | 3.42 V (0.5%) | 71.9 W | ✓ OK (≤3%) |
| 35 mm² | 125 A | 97 A | 1.48 V (0.21%) | 688.5 V | 2.45 V (0.35%) | 51.4 W | ✓ OK (≤3%) |
| 50 mm² | 151 A | 118 A | 1.04 V (0.15%) | 689.0 V | 1.71 V (0.25%) | 36.0 W | ✓ OK (≤3%) |
| 70 mm² | 192 A | 150 A | 0.74 V (0.11%) | 689.3 V | 1.22 V (0.18%) | 25.7 W | ✓ OK (≤3%) |
| 95 mm² | 232 A | 181 A | 0.55 V (0.08%) | 689.5 V | 0.9 V (0.13%) | 18.9 W | ✓ OK (≤3%) |
| 120 mm² | 269 A | 210 A | 0.43 V (0.06%) | 689.6 V | 0.71 V (0.1%) | 15.0 W | ✓ OK (≤3%) |
| 150 mm² | 309 A | 241 A | 0.35 V (0.05%) | 689.7 V | 0.57 V (0.08%) | 12.0 W | ✓ OK (≤3%) |
| 185 mm² | 353 A | 275 A | 0.28 V (0.04%) | 689.7 V | 0.46 V (0.07%) | 9.7 W | ✓ OK (≤3%) |
| 240 mm² | 415 A | 324 A | 0.22 V (0.03%) | 689.8 V | 0.36 V (0.05%) | 7.5 W | ✓ OK (≤3%) |
| 300 mm² | 477 A | 372 A | 0.17 V (0.03%) | 689.8 V | 0.29 V (0.04%) | 6.0 W | ✓ OK (≤3%) |
| 400 mm² | 570 A | 445 A | 0.13 V (0.02%) | 689.9 V | 0.21 V (0.03%) | 4.5 W | ✓ OK (≤3%) |
FAQ — 20 Amp Cable Size at 70 Meters (690V Three-Phase (Wind / Heavy Industrial))
What mm² cable size is required for 20A at 70 meters (690V)?
According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 4 mm² copper cable for 20A over 70m at 690V (voltage drop: 12.97V or 1.88%).
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 · 20m (690V)20A · 25m (690V)20A · 30m (690V)20A · 35m (690V)20A · 40m (690V)20A · 45m (690V)20A · 50m (690V)20A · 60m (690V)10A · 70m (690V)16A · 70m (690V)25A · 70m (690V)32A · 70m (690V)40A · 70m (690V)50A · 70m (690V)63A · 70m (690V)80A · 70m (690V)100A · 70m (690V)125A · 70m (690V)160A · 70m (690V)200A · 70m (690V)