Different Types of Electrical Motor Faults Can Occures

There are so many different ways to occur electrical motor faults while on working condition of the motor and following are some simple methods of fault identifications. Every electric motor has operating limits so Overshooting these limits will eventually destroy it and the systems it drives, the immediate effect being operating shutdown and losses.The major faults of any electrical motor can divide in to two and those can classified as Electrical faults and Mechanical faults. Some of major electrical and mechanical faults mentioned in bellow.

Electrical Motor Faults

•    Power surges
•    Voltage drops
•    Phase unbalance
•    Phase losses causing
•    Variations in the absorbed current
•    Short circuits

Mechanical Faults occur in Motor

•    Locked rotor
•    Momentary or prolonged overloads
•    Increasing the current absorbed by the motor
•    Heating windings of motor
•    Winding open circuit
•    Winding short circuit

The cost of these incidents can be high. It includes production loss, loss of raw materials, repair of the production equipment, non-quality production and delivery delays. These incidents can also have a serious impact on the safety of people in direct or indirect contact with the motor. These protections are ensured by special devices such as fuses, circuit breakers and overload relays or by integral devices with a range of protections.

How to  Trouble Shoot Electrical Motor Faults

Following are some guidance to take to Trouble Suite an Electrical Motor and before you start to work on the motor, MAKE SURE THE POWER IS OFF. Always turn the power off at the electrical service entrance breaker box or fuse, to prevent electrical shock.


  1. Check for blown line fuse or tripped breaker.

  2. Allow motor to cool and try to reset.

  3. One of the most common problems in a work shop is a build-up of dust in the motor, especially with open drip proof motors.

  4. Give the motor a shot of air to blow out the dust, nine times out of ten this will get the motor to start again, to fix the problem the motor should be replaced with a totally enclosed, fan cooled model.


Excessive vibration.

  1. Check for loose mounting.
  2. Check shaft alignment.
  3. Check for bent shaft.

Excessive noise.

  1. Check for damaged bearings. Replace as necessary.
  2. Check for rotor rub by rotating the shaft slowly by hand.


  1. Be sure motor vent holes (or fan blades) are free of obstructions.
  2. Use a shorter or heavier gauge extension cord.

Hope that these motor troubleshooting methods will helpful when motor got malfunction.

Leave a Reply