Technical Support
Phase Converter Amperage Guide
Understanding the amperage characteristics of your phase converter helps you plan your electrical service, select the correct wire and breaker sizes, and verify that your existing service is adequate. This guide explains input and output amperage for Phoenix rotary phase converters and provides reference tables for common converter sizes.
How Phase Converter Amperage Works
A phase converter converts single-phase AC power to three-phase AC power. Because single-phase must supply all three-phase output power, the input current is higher than what a three-phase utility service would draw for the same load. This is normal and expected.
Key rule: The single-phase input to a rotary phase converter draws approximately 1.73× more amps than the three-phase equivalent load at the same HP and voltage.
Input Amperage Reference (240V Single-Phase)
| Converter HP | Running Amps (Input) | Input Breaker | Input Wire (Cu) |
|---|---|---|---|
| 3 HP | 14–16A | 20A | #12 AWG Cu |
| 5 HP | 23–26A | 30A | #10 AWG Cu |
| 10 HP | 45–52A | 60A | #6 AWG Cu |
| 15 HP | 65–72A | 90A | #4 AWG Cu |
| 20 HP | 88–97A | 110A | #3 AWG Cu |
| 30 HP | 128–140A | 175A | #1 AWG Cu |
| 50 HP | 200–225A | 250A | 350 kcmil Cu |
Service Entrance Planning
Your single-phase service entrance must have enough spare capacity for the converter's input current plus all other single-phase loads. A 200A service handles most shop applications up to 25–30 HP. Larger converters may require a 320A or 400A service.
Use the free sizing calculator or call 602-962-8859 for specific amperage figures for your converter size and load.
- GP5NL – 5 HP Rotary Phase Converter
- GP10NL – 10 HP Rotary Phase Converter
- GP20NL – 20 HP Rotary Phase Converter
- Full NL Series Collection
- Free Sizing Calculator
Ready to Get Three-Phase Power?
Call 602-962-8859 for expert sizing help, or shop Phoenix phase converters to order today. Every Phoenix phase converter ships with a lifetime warranty and same-week lead times.
Talk to a Phase Converter Engineer
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