How to Troubleshoot a 3-Phase Electric Motor
- Common hand tools
- Volt ohmmeter with probes
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Take input voltage to the motor using the volt ohmmeter. The motor-specified voltage must be present on all three phases. If not, check supply circuitry, breakers and condition of the motor's power cord. If the voltage is good, go to Step 2.
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Examine the motor's electrical connections and terminals. Remove power to the motor and repair any damaged or loose connections.
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Remove motor voltage and disengage the motor from the machine that it is running. Reconnect motor voltage and see if the motor now runs. If it does, check the machine for serviceability. If not, go to Step 4.
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Check the motor for heat or burnt smell. Clean motor windings and housing with shop air or vacuum and then try to restart. Replace motor if it will not restart.
