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10 HP 3 Phase Converter
The complete guide, sizing calculator, and wiring resource for 10 HP Rotary and Digital Phase Converters. Run your CNC, compressor, or welder on single-phase power.
Size Your ConverterWill a 10 HP Converter Run My Machine?
Enter your equipment details to see if a 10 HP phase converter is the right size, or if you need to upsize for hard-starting loads.
Required Converter Size
Estimated Running Amps
Starting Amps Required
10 HP Converter Specifications
What to expect from a standard 10 HP Rotary Phase Converter (RPC) at 230V.
Running Output
Starting Capacity
Input Power
Breaker Size
What Can a 10 HP Converter Run?
A 10 HP phase converter is the sweet spot for serious home shops and small industrial facilities.
CNC Machines
Haas, Tormach, and Bridgeport CNC mills run perfectly on a 10 HP RPC. Smooth, balanced 3-phase power.
Engine Lathes
Classic South Bend, Logan, or Enco lathes up to 10 HP. Provides the torque needed for heavy cuts.
Air Compressors
Runs 5 HP compressors easily. For a full 10 HP compressor, you must upsize to a 20 HP converter due to starting load.
Welders & Plasma
Miller, Lincoln, and Hypertherm 3-phase welders and plasma cutters up to 10 HP input rating.
Dust Collectors
High-velocity 10 HP dust collection systems for large woodworking shops. Handles the initial spin-up load.
Hydraulic Presses
10 HP hydraulic power units for shop presses and industrial bending equipment. Consistent pressure output.
Basic Wiring Guide (230V)
How to connect a 10 HP Rotary Phase Converter to your single-phase panel and 3-phase equipment.
Connect Single-Phase Input (L1 & L2)
Run your 230V single-phase power from a 60A double-pole breaker to the converter's input terminals marked L1 and L2. Connect the ground wire to the chassis ground.
Identify the Generated Leg (L3)
The converter generates the third phase, usually marked L3 or "Wild Leg". This leg will read a higher voltage to ground (approx 208V-240V) compared to L1 and L2 (approx 120V). This is normal.
Connect 3-Phase Output to Equipment
Run wires from the converter's output terminals (L1, L2, L3) to your machine's disconnect switch or contactor. Ensure the motor is wired for 230V 3-phase (usually a 9-lead motor wired in Delta or Wye configuration).
Install Start/Stop Controls
Wire a magnetic contactor or a manual disconnect switch between the converter and the machine. Never wire a 3-phase machine directly to a wall outlet without proper overload protection.
Frequently Asked Questions
Can a 10 HP converter run a 10 HP motor?
Yes, but it depends on the load. For soft-starting loads like CNC machines and lathes, a 1:1 ratio (10 HP converter for 10 HP motor) works perfectly. For hard-starting loads like air compressors, you need a 2:1 ratio (20 HP converter for 10 HP motor).
What size breaker do I need for a 10 HP converter?
A 10 HP rotary phase converter at 230V typically draws about 40-50 amps on the single-phase input. You should use a 60 Amp double-pole breaker and 6 AWG copper wire for the input supply.
Rotary vs. Digital Phase Converter: Which is better?
Rotary (RPC): Cheaper, handles high starting currents, great for motors, compressors, and old machinery. Digital (VFD/Solid State): More expensive, provides clean power, allows variable speed control, best for CNC machines and sensitive electronics.
What is the "Wild Leg" or "High Leg"?
In a 240V 3-phase system generated by an RPC, the generated leg (L3) will read a higher voltage to ground (around 208V) compared to L1 and L2 (around 120V). This is completely normal. Do not connect any 120V single-phase loads to the wild leg.
Do I need capacitors on a 10 HP converter?
Yes. Rotary phase converters use start capacitors (to help the idler motor spin up) and run capacitors (to balance the 3-phase voltage under load). Most quality 10 HP converters come with a capacitor bank pre-installed and tuned.
Power Your Workshop
Get the right 10 HP phase converter for your machinery. Safe, efficient, and reliable 3-phase power.
Calculate Your Needs