3 Phase Wire Size Calculator
// SIZE THREE PHASE CONDUCTORS FROM LOAD, VOLTAGE, RUN LENGTH, MATERIAL, CONTINUOUS-DUTY LOAD, AND VOLTAGE-DROP TARGET //
Load Current
80.0 A
Design Amps
100.0 A
Meets ampacity and voltage drop
3 AWG
100 A ampacity, 5.1 V drop, 1.06% voltage drop.
Ampacity-only minimum
3 AWG
Voltage drop may require upsizing beyond this minimum on long three phase runs.
Three phase current uses I = kW x 1000 / (sqrt(3) x V x PF x efficiency), or I = kVA x 1000 / (sqrt(3) x V). Voltage drop uses the one-way circuit length and conductor resistance.
Ampacity values are planning references based on common 75C copper and aluminum conductor columns. Final installations still need terminal temperature, insulation type, ambient correction, conductor bundling, equipment instructions, overcurrent protection, and local code review.
| Conductor | Ampacity | Voltage Drop | Status |
|---|---|---|---|
| 14 AWG | 20 A | 13.29% | Check |
| 12 AWG | 25 A | 8.36% | Check |
| 10 AWG | 35 A | 5.24% | Check |
| 8 AWG | 50 A | 3.31% | Check |
| 6 AWG | 65 A | 2.13% | Check |
| 4 AWG | 85 A | 1.33% | Check |
| 3 AWG | 100 A | 1.06% | Pass |
| 2 AWG | 115 A | 0.84% | Pass |