Compressor Motor pops breaker - but only sometimes

by Donna
(Shelby, NC)

Motor Hmms for about 1 minute then pops breaker. If I turn the motor by hand then flip the breaker it starts up. It may do this once or twice a day. I was told that it is leaving pressure on the compressor. If I put a brand new motor on, it will last for about a year then start doing the same thing again. This will be the 3rd motor I've put on this compressor in 3 years

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Bill says...

Hi Donna...

If you use the compressor daily, and it's always running at capacity, then I don't think it unreasonable that you might use up a motor a year.

Having said that, if you are an intermittent user, then that does seem unusual.

There are many things that could be contributing to the problem. One that pops to mind immediately is current draw.

Your compressor needs enough electrical energy, delivered by the power cord from the receptacle, and from the capacitor, to start properly. Failure of supply (too many other electrical appliances running at the same time on the same electrical circuit) can cause the motor to under-perform and overheat, this leading to premature motor failure.

If the capacitor hasn't enough ooomph to kick over the motor when the pressure switch calls for a start, the circuit draws too many amps, and blows the breaker.

Low voltage or failing capacitor could cause the humming as the motor tries to start.

It were me, I'd start by getting a clean power supply (only the compressor on the whole circuit) and then monitor any change in performance.

Cheers and good luck,

Bill