Electric motor failure stems mostly from damaged bearings or stator windings. However, there are a number of other reasons they can fail.
The most common failures in order are:
- bearing failure
- stator winding failure
- power supply anomaly
- unusual mechanical loads
The main reasons for bearing failure are:
- improper lubrication
- electrical discharge across the bearing
Stator Winding Failure
Electrical insulation deteriorates at a rate that doubles for every 10°C increase in temperature.
The reasons for overheating are numerous and include:
- too many starts
- high ambient temperature
- coolant failure
- low or unbalanced voltages
Power Supply Anomaly
- voltage unbalance
- voltage spikes
If the motor is stopped and cools down it may drop below the dew point. Moisture weakens the insulation and contributes to bearing corrosion.
This results in: abrasion, corrosion and overheating. Small particles in the windings can gradually wear the insulation away as the wires flex during operation.
Electric motor failure is a large subject area with specialist knowledge required in a number of disciplines to enable a robust design to be made. We would welcome contributions from hobbyists, researchers and commercial organisations alike. Drop us a line at email@example.com