Can pump capacitors function intermittently?

[Auburn02]

Dad and I installed a new Polaris PB4-60 pump at his equipment pad less than a year ago; in the past few weeks, he's had a couple instances of the pump failing to power on, only to come on just fine perhaps the next day or in one case not until three or four days later. I know the motor isn't seized. I was thinking maybe a poor connection somewhere, water in an electrical box or some other sort of issue that might come and go. Just yesterday he finally clued me in that he does hear a humming from the motor when it would fail to come on, which to me indicates a possible capacitor issue. But my question is would it make sense to have a capacitor fail to start the motor one day only to work fine a day or two later, rather than failing outright? Or if not, what else would that indicate?

 

[1poolman1]

A failing capacitor might function that way, but usually they work or don't. Lately, there has been an issue with the motors Polaris has been using failing. Yours isn't the first I've heard of in the last year or so. Virtually all motors are made in China now and the quality just isn't there.

 

[Auburn02]

I guess I am not discounting the possibility, but trying to wrap my mind around how if the motor was failing why it would fail to start one day and then start fine the next. Seems to indicate more a start/initialize problem than a motor problem, but I clearly don't know what I don't know.

I've not had an opportunity yet to be there in person when said start failure occurs, to see if I can spin the pump manually to get it to start (assuming that is in fact possible like I've read).

 

[JamesW]

Just replace the capacitor.

You can test it if you have a capacitance setting on your multimeter.