Testing 3 phase motors

[Canadium]

I have a couple of used 220V 3phase motors I'm hoping to use in my projects. Thought I should start by testing the motors. I don't have a megger but do have a couple of multimeters. Followed the protocol on link below for the multimeter tests. Everything there looks good. Is a megger test a better way to analyze the motors condition?

How to Test a 3 Phase Motor Windings With an Ohmmeter

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[Tom Kitta]

I just... plug them in. I also assume all 3ph motors that do not look like they were hit by a truck are working. So far, after dealing with dozens and dozens of 3ph motors I have yet to find a single one that does not work.

I think burning out 3ph motor today is very rare as most are part of industrial machinery that is protected with magnetic switch and associated overload breaker (they are like 99% together).

Heck, I would not be surprised if some motors hit by a truck, but not too hard, were working as well. Some motors abandomed in farmer fields for years, loaded with mud, worked fine after removing all soil and grass from them. I guess maybe mice getting in could be an issue - especially for motors that are not fully enclosed. Or some serious rust issues - like rusting through the frame.

 

[Brent H]

@Canadium : “typically” 3 phase motors only have issues with:

Worn bearings ( typically easy change and should be done on any suspect motor)

Insulation breakdown: old motors that were in frequent use (age) or - high temp environment, ran with alignment issues (over heating)

Foreign particulate - contamination. So a “drip proof motor - not sealed (TEFC) and full of grease, fillings etc that help with heat build up or shorting things out.

Pretty robust. A megger test will help determine a condition - say a motor used in a damp, wet environment or such. Lots of motors are good to go with a proper cleaning, drying out and new bearings.

 

[trlvn]

@Canadium I have an old megger here (OK, actually two) if you wanted to try that test. I know very little about such things--these are left over from my late brother's estate.

Craig

 

[Brent H]

@Canadium and @trlvn - bring it with you to the meet and greet. We can show others