How to Balance a Rotary Phase Converter

Rotary phase motors are also known as three-phase motors and are usually found in residential air-conditioning units. These motors are called three-phase motors because they use three-phase electrical systems. The voltage balance across rotary phase motors is important to keep the motor and the AC unit working properly. If you need to balance the voltage through a converter, use a capacitor to balance out the voltage loads. You don’t have to be an HVAC technician to balance your phase converter; you can do it yourself.

Voltmeter
Screwdriver
Pliers
Capacitor (phase rated)

Instructions

- 1
  Get a voltage reading across the three voltage terminals on your motor using a voltage meter. Switch the voltage meter to “Volts” and put the leads on the start winding and the terminals.
- 2
  Write down the voltage readings from your terminals. The voltages should have no more than a five percent difference.
- 3
  Go to your breaker box and turn off the AC unit.
- 4
  Disconnect the terminal from the engine that has the lowest voltage. Connect a phase rated capacitor to the terminal that's lagging. This will balance out the voltage coming into the terminal.
- 5
  Turn the AC unit back on at your breaker box and take another voltage reading across the terminals. The voltage should be balanced.

What Would Cause Me Not to Have High Voltage to My Air HVAC Unit?

The Size for a Central Air Conditioner by Square Footage

Air Conditioners