Three-phase output wire size
Sizing the run from the converter to your sub-panel or machine. Figures assume 240V three-phase, copper conductors, 75°C terminations and a run under about 100 ft.
| Converter / motor | Approx. motor FLA | Breaker | Copper conductor |
|---|---|---|---|
| 3 HP | ~9.6 A | 15–20 A | 14 AWG |
| 5 HP | ~15.2 A | 20–30 A | 12 AWG |
| 7.5 HP | ~22 A | 30–40 A | 10 AWG |
| 10 HP | ~28 A | 40–50 A | 10 AWG |
| 15 HP | ~42 A | 50–60 A | 8 AWG |
| 20 HP | ~54 A | 70 A | 6 AWG |
| 25 HP | ~68 A | 80–90 A | 4 AWG |
| 30 HP | ~80 A | 100 A | 3 AWG |
Notes for the output side
- Size from each machine's nameplate full load amps. Motor nameplates vary, so never assume the table value is exact for your machine.
- Feeding several machines from a sub-panel? Size the feeder for the largest motor plus the running current of the others.
- Identify the manufactured leg and keep it off 120V control circuits and single-phase transformers.
- Each machine still needs its own overcurrent protection and disconnect as required by code.
- For runs longer than about 100 ft, increase the conductor one size for every additional 100 ft to keep voltage drop under 3%.
Planning guidance only. Final sizing must come from your nameplate values and the National Electrical Code, applied by a licensed electrician.
Still need the supply side? See single-phase input wire size or the wiring diagrams.