Bench Grinder - Overheating

Mongo was using the old IR bench grinder we restored.
SAVED Old IR Bench Grinder - • SAVED Old IR Bench Gri...
After a bit of use the body of the grinder was burn the flesh HOT.
Couple things can cause overheating. Bad bearings, bad motor windings or a bad capacitor.
BE CAREFULL AND SAFE, when working with electricity and capacitors.
Test the capacitor - Ohm meter and capacitor meter.
Using an Ohm meter touch each terminal of the cap and the reading should fluctuate. Switch to capacitor test and it should read the rated farad rating of the cap.
00:00 HIs STORY
01:00 Testing a BAD capacitor
02:02 Motor winding test
Motor test - Ohm meter and measure each end of the different coils. On a 3 wire AC motor (lead A, B, C) measure Lead A to B, B to C and A to C. Measurement of A to C should be the same as adding up A to B and B to C. Would need the spec of the motor to know if the windings measurements are correct
04:29 Split phase AC motor
All sorts of different type of AC motors. Be sure you know which type you are working with. This is a PSC AC motor. This type of motor has the capacitor PERMINENTLY attached to each coil. No disengagement of the capacitor circuit.
05:57 Capacitor Identification
Should have a label with the manufacture, MFD rating, voltage, PN etc...Make sure to get the same capacitor as the one previously installed.
07:13 Testing a GOOD capacitor
08:47 Testing Grinder
Hopefully this video help you if you have a bench grinder with a PSC motor that is overheating.
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MONGO THANK YOU!!!

[@starflash08]

Thanks so much for this, I thought my grinder was about to burn up, turns out is was the capacitor just like your one, thanks for the knowledge of using the meters

[@mongofix]

You most welcome! very glad this help you!

[@michaelhoward1900]

TY for posting this video. I have a old grinder from a garage sale that heats up pretty fast. Here's the catch. It doesn't have a capacitor on the outside or underneath. Is it possible it never had one and the heating is caused by old dry bearings?

[@mongofix]

Couple things can cause grinders to heat up, shorted capacitor, bearings, shorted motor windings. It always trick when getting stuff from garage sale. Never know what someone has done with it. First need to confirm what type of motor it is. (maybe it missing a capacitor) Test bearings, and motor windings. Mongo made video of replacing bearings, check it out!

[@6atlantis]

I just bought the 8in Bauer variable speed from H.F. I like it and had used a wire wheel on it a few times with no problem or excessive heat. Finally yesterday it was flesh burning hot after I was really torquing on the wire wheel for a good ten min. Should I test the capacitor or is it just the best I can expect from a harbor freight grinder? They are much smoother than they were even just a few years ago which is why the overheating is disappointing me.

[@mongofix]

Is the CAP permanently connected or switched? Does it get hot every time now? or Just under heavy torque or extended time? HF uses cheap cheap materials so this could be normal. If just got it, might be able to return/exchange it. If take it apart, might not be able to return it. Mongo would check it out, but Mongo always curious.

[@TheDirtbikerdude]

👍

[@mongofix]

Mongo thank you much!!!