Central Pneumatic Air Compressor Motor slows, stops (and hums), then trips overload switch

by Dave L.
(Becket, Massachusetts)

This sometimes happens right after it's achieved full speed. It suddenly just slows down.


I can turn the compressor shaft easily by hand. The start capacitor checks out fine.

It's a head-scratcher. Anyone?

Dave L.

Comments for Central Pneumatic Air Compressor Motor slows, stops (and hums), then trips overload switch

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Aug 12, 2014
Problem Solved!
by: Bill

Glad to hear it Dave.

And thanks!

Bill

Aug 12, 2014
Problem Solved!
by: Dave L.

Sorry so long to report back. It was as easy as I'd hoped. When I put the thing back together again and plugged it into a wall outlet (no extension cord or power strip) it worked fine. Who knew? Not me.

Thanks to everyone for your help. And to Bill for running this fine forum. Saved me a hundred bucks. :)

Jun 30, 2014
centrifugal switch and start cap
by: Dave L.

FYI... centrifugal switch seems fine. That was the first thing I checked. Start cap reads good.

I just need to finish putting this thing back together and test it without extension cord or power strip. One terminal on the start cap was soldered; I cut the wire to get it apart, so I've got a little work to do there to replace it with a solderless lug or re-solder it.

More, soon...

Jun 26, 2014
slowdown
by: Doug in s.d.ca

A model number might be useful, but:

I understand you as saying that *sometimes*, right after it starts, it slows down again...

Sounds like a flakey centrifugal start cap switch. Internal to the motor. If it fails to open it could cause this. Try not to run it that way, as it could take out your so-far good start cap.

I am assuming there is no run cap.

Jun 26, 2014
OK, first things first
by: Dave L.

Dave, here. I did some further reading on the website after posting this issue. Looks like I need to try the compressor without an extension cord or power strip. I had no idea that could limit the power input to the compressor motor.

Great site. I'll report back.

Dave L.

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