Diagnosing Motor Winding Damage

1. All windings dark brown or burnt black The source associates this pattern with prolonged overload. Heat accumulates until winding insulation melts and a short circuit

Article details

1. All windings dark brown or burnt black

The source associates this pattern with prolonged overload. Heat accumulates until winding insulation melts and a short circuit occurs, potentially because the pump or gearbox load is obstructed or the motor is undersized.

2. Only some phases burnt

Phase failure or single phasing in a three-phase motor may result from a broken cable, blown fuse, faulty breaker or poor contactor contacts. Current in the remaining phases can cause overheating and damage.

3. Localized burns or winding short circuits

Localized insulation damage may result from moisture, water ingress, corrosive chemicals or metal particles abrading the insulation, causing an inter-turn short circuit.

RELATED EQUIPMENT