Common electric motor problems — and easy fixes

"Reduce, Re-use, Recycle."  Here’s something that relates to the “Re-use” aspect. It's obvious that very many tools — and pieces of equipment useful in the home, yard, or homestead — rely on electric motors.  A lot of this electric equipment gets junked needlessly.  Very often you can repair the motor.

This instructive video addresses the three most common problem points with AC and DC electric motors — the capacitor, the brushes, and bearings.  This is pretty cool stuff, and I learned things from this vid.  As the guy mentions, some of his other videos focus on related matters and certain details

Joel Bercardin wrote:"Reduce, Re-use, Recycle."  Here’s something that relates to the “Re-use” aspect. It's obvious that very many tools — and pieces of equipment useful in the home, yard, or homestead — rely on electric motors.  A lot of this electric equipment gets junked needlessly.  Very often you can repair the motor.

This instructive video addresses the three most common problem points with AC and DC electric motors — the capacitor, the brushes, and bearings.  This is pretty cool stuff, and I learned things from this vid.  As the guy mentions, some of his other videos focus on related matters and certain details

Yep but you can also have other not-easy-to-fix problems.

Internal grounds/shorts.
Requires a rewind job. (I once worked in a rewind shop - burnout ovens and bake ovens and such - HOT work too. Glad I found a different job).

Also go try to find those bearings and brushes for a car alternator or starter or even a home window box fan. Or even the diode pack for a GM alternator in a car parts store. NONE will see the parts. ALL want to sell you a reman one instead. And for a high price too.

I do have a real capacitor checker. Tells me the capacitance.

Good points you've made, Kai.  Yeah, DIY initiative & experience are good, but there are always those things that can be next to impossible to do, given the actual extent of a person's knowledge & tools.

Had to burnish commutators too.
Undercut Mica, etc

And a mega-ohmmeter is a must in most cases.

Edit: and slip rings as well.

Used a stroboscope to check rpm's to ensure they run at the proper speed too.

A real motor-generator setup is probably the best for smooth power vs a DC generator running a static inverter.

Correction: not MUST but can be of good use in some cases.

Kai Walker wrote:Had to burnish commutators too.
Undercut Mica, etc

And a mega-ohmmeter is a must in most cases.

Edit: and slip rings as well.

Used a stroboscope to check rpm's to ensure they run at the proper speed too.

A real motor-generator setup is probably the best for smooth power vs a DC generator running a static inverter.

Generally, most DIY learning & doing seems to start with the easiest stuff first.  That's what the guy was explaining in his vid.

If you are going to get an ohmmeter/voltmeter get one that dies a/c and d/c amps, clamp on style too.

Amp draw can save you time in your diagnosis.

https://www.harborfreight.com/digital-clamp-meter-96308.html

A decent mega ohmmeter can run you about $600 if you are serious about things.

I usually get by without one.

Prophecy sought.
An old box fan works great on high but really slow on the low setting. So slow that I have to spin the blade to get it going...and then it gave up the ghost on both settings. Any opinions on fixing the thing? It's a nice older model with a larger motor housing. How do I getthe blade off without breaking it? It's really stuck.

Hey guys I just took my 1st electric  motor apart to fix some minor wiring when I put it back together seems to be some friction when the ar armature spins is this normal?


     

Hi Burl,

I know the post is from a year ago, but I see you are still active.  It sounds like a good oiling is what it needs for both problems. By any means, that is a good place to start.