How to test a shaded-pole fan motor

Shaded-pole motors are the simple, low-power AC motors with copper shading rings on the pole pieces. They have one winding, no capacitor and a weak starting torque, so they usually fail from dry bearings rather than burned windings.

Single source ~20 min easyBrands: 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
Live-voltage checks are a caution step: insulated probes, one hand, clips attached before power is restored, stay clear of terminals
Keep fingers clear of fan blades when power is restored

Diagnostic steps

Unlock all 6 steps with expected values

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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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