How Electric Motors and Generators are the Same Device

An interesting topic came up in conversation while speaking to a customer recently about motor repair. We were discussing failures types and how we handle each, going over what is included in the repair and generally just having a nice chat about repairs in general. Towards the end of the conversation he asked – almost as if it were an afterthought- “do you guys repair generators as well”?  I answered “well, of course”. He then replied “ok why don’t you tell me what you repair on a generator”. With a chuckle I explained that I just did, and that an Induction Motor and a Generator are essentially the same device. He did not seem to believe me so I explained how they both work off the principles of induction, but opposite of each other. While an electric motor converts electricity into mechanical work, a generator converts mechanical work into electricity. Here is how.

What is Inductance?

To understand this, we first must examine what inductance is. Inductance is the property of a conductor – such as the copper coils within a motor – to produce electromotive force according to a change in current through it. In the case of an electric induction motor, current is applied to the coils of the motor resulting in a magnetic field which moves the shaft of the motor granting mechanical force to a system. In a generator the opposite occurs, rather than apply electricity to the coils, mechanical energy is instead applied to the shaft usually by some sort of gas powered engine which creates a rotating magnetic field. A voltage difference between with winding and the stator occurs causing current to flow. This output current can then be converted to useable energy.

How are Motors and Generators Similar with Regard to Repair?

Motors and generators share much of the same failure modes. They both have Rotors which, in order to spin, must ride on bearings. This is load point where many stress risers form. Over half all motor and generator repairs start with a failure of a bearing. In addition to bearings, winding failures, shaft wear, contamination and other common mechanical issues can occur in both Electric Motors and Stators.

Remember, if you have any problems with your Motors or Generators give us a call! Also be sure to visit us online at or call us at 1-877-249-1701 to learn more about our services. We’re proud to offer Surplus, Complete Repair and Maintenance on all types of Industrial Electronics, Servo Motors, AC and DC Motors, Hydraulics and Pneumatics. Please subscribe to our YouTube page and Like Us on Facebook! Thank you!

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