How to Do Quick Electric Motor Repairing

Electric Motor Repairing

What would you do if you have an electric motor which is built to run on alternating current but not?

This Instructable relates to a triage process for restoring electric motors or electric motor repairing procedures and having your capacitor start the motor working again in a sequence of quick and logical steps.

Let’s say you have a 1/4 or 1/2 horsepower single-phase engine, maybe even up to 1 horsepower. It may have one capacitor, but it may have two as well. The function of the motor can be to start the condenser or run the condenser.

These types of engines are what you can encounter in most applications at home and the workshop. There will be some variations between the specific function of industrial motors (DC, three-phase) and I know nothing about them.


This Instructable is published to impart some useful stuff I’ve learned, as well as some knowledge and techniques that you’ll find useful. The aim is to give the reader some support to carry out some cautious tests and fix some underlying issues.

Please don’t ask me to remotely diagnose your motor and tell you how to fix it. I do not have the facilities to do it. Choose a book like the one I purchased (see step 6), check the internet for articles and watch some videos.

Then, in a logical order, do some careful checking—anything to a purpose. Be ready to give up on your assumptions. Procedures of electric motor repairing need to be done correctly. Be patient. Even you can get your engine going again.

Needed Materials

● Bearing grease

● 16-3 power cord and plug (if old cords needed to be replaced)

Tools Needed 

● a round praying tool that is sharply pointed (to raise seals on bearings)

● punch, hammer, and flat surface (before reinstallation, for smoothing the bearing seals) 

● solder and soldering gun

● Nut drivers

● Volt-Ohmmeter

● Screwdrivers

● capacitance meter 


#1 Spin by Hand

Electric Motor Repairing
Electric Motor Repairing

Switch hand over the shaft of the engine. Can running turn around quickly enough? There’ll still be some friction, but the shaft will be rotating reasonably freely.

Even so, an older motor may have dried grease bearings. If the bearings are not clogged inside, you will usually be able to work clean oil into them and significantly boost them.

#2 Add Power for a Few Seconds

Only add power for a few seconds. Ideally, there aren’t any fires or vibrations from the motor assembly so that the circuit breaker won’t fly right away.

Check for discoloured wires in the power cord that contact another discoloured wire or shortcuts to the engine’s iron frame, if you have either of that stuff.

Coil windings within the motor heat up quickly on an engine that is not working, and the coils can be fried. Then the engine needs to be reset to get back to running.

#3 Check for Shorts and Opens

Unplug motor from the source of power. Disable the connectors cover plate, remove the end of the motor where the power cord connects to the windings if there are no connectors on the motor. Use an Ohmmeter. Many propose a set of around 2000 Ohms.

#4 The Centrifugal Switch

Some Of The Basics To Know About Electric Motor Repairing
Some Of The Basics To Know About Electric Motor Repairing

Capacitors enable electric motors to generate an advancing magnetic field in the stator using a starting coil and a condenser. This evolving magnetic field lets the rotor pursue something, blades of a turbine to spin.

#5 The Capacitor

When a capacitor fails, a condenser can bulge or leak. It could break open also. However, it could look perfectly natural too. There are different condenser test processes, but these tests are not foolproof. A condenser can pass a few tests under a load, and still fail.

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