Electric drive motor removed from a washing machine
Generic photo: Poo (Wikimedia Commons user) · Public Domain

How to test a PSC motor (common, start and run windings)

Permanent split capacitor (PSC) motors are used in AC condenser and blower fans, some washer and dishwasher motors. Test the capacitor first, then the three windings. The two individual readings must add up to the start-to-run reading, and nothing may read to ground.

Cross-checked ~30 min moderateBrands: All

Before you start

  • Unplug the appliance or turn off the breaker before opening panels or disconnecting parts
  • Take a photo of the wiring before removing any wire
  • Resistance and continuity tests are done with power OFF and the part isolated
  • Discharge the run capacitor before touching it (resistor across the terminals); it can hold a charge
  • Live-voltage checks are a caution step: insulated probes, one hand, clips attached before power is restored, stay clear of terminals

Diagnostic steps

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OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work.

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