Humming noise without rotationNo noise or movement on start commandStarts but trips breaker immediately
A step-by-step diagnostic guide for troubleshooting an electric motor that refuses to start or start up under load.
Probable Cause: Power supply failure, open control circuit, blown fuses, tripped overload relay, mechanical binding, or internal winding faults.
Breaker trips immediately upon resettingBreaker trips after several minutes of operationBreaker handle is warm to the touch
How to identify why a circuit breaker keeps tripping and isolate whether the cause is an overload, short circuit, or ground fault.
Probable Cause: Overloaded circuit, short circuit (neutral-to-hot), ground fault (hot-to-ground), or a degraded/defective circuit breaker.
Three-phase motor running extremely hotNuisance tripping of motor protection relaysAbnormal humming or vibration in transformer
Diagnose and calculate voltage imbalance in three-phase systems, and learn the destructive effects of unbalanced voltages on motors.
Probable Cause: Uneven distribution of single-phase loads, faulty power factor correction capacitors, or utility line issues.