Pool pump motor help, please.

Thread Starter

joeyd999

Joined Jun 6, 2011
4,327
Motor is a few years old. Power on makes loud buzz for 2 seconds and breaker trips. Rotor turns freely.

Is it cap or do I need new motor? How do I test?

As smart as I am, I am an engineer, not electrician. I have great respect for electricians!

IMG_20180523_171019.jpg IMG_20180523_171011.jpg
 

MrSoftware

Joined Oct 29, 2013
1,674
Was it previously working and just stopped? Or are you wiring it up for the first time? Could be the capacitor, but they also do that if you wire them wrong. i.e. if the pump is wired for 110 and you connect it to 220, or vice versa. Many of those pumps will operate on both, you have to change some wires under the cover to select which one.
 

MaxHeadRoom

Joined Jul 18, 2013
19,981
A new cap could be the first option to try.
OR if a start switch is fitted internally, try giving it a spin as fast as possible in the proper direction and then apply power, if it runs then you pretty much know the motor is OK.
Max.
 

Thread Starter

joeyd999

Joined Jun 6, 2011
4,327
Was it previously working and just stopped? Or are you wiring it up for the first time? Could be the capacitor, but they also do that if you wire them wrong. i.e. if the pump is wired for 110 and you connect it to 220, or vice versa. Many of those pumps will operate on both, you have to change some wires under the cover to select which one.
Motor has been in use for a few years. Just quit yesterday.
 

Thread Starter

joeyd999

Joined Jun 6, 2011
4,327
A new cap could be the first option to try.
OR if a start switch is fitted internally, try giving it a spin as fast as possible in the proper direction and then apply power, if it runs then you pretty much know the motor is OK.
Max.
Shaft is not exposed to "give it spin". Even if it was, I'd have no way to spin it without killing myself.

Fyi, these things make me nervous.
 

MrSoftware

Joined Oct 29, 2013
1,674
If it was in service and just quit, then check the cap. Make sure there is no power, short the cap to make sure it is discharged, disconnect it and measure it with your multimeter if it will measure capacitance. Or just pickup a new one if it's not too expensive and give it a try. :)
 

Ylli

Joined Nov 13, 2015
891
You could probably check the centrifugal switch first - it's that white block near the bottom. If that seems to be working OK, then the cap would be the next step.
 

MaxHeadRoom

Joined Jul 18, 2013
19,981
When replacing the cap ensure it is a Motor start rated, these are generally bi-polar electrolytic.
As to nervous about spinning it there is a slot in the rear shaft you could put a power tool on with a screwdriver bit!;)
Max.
 

Reloadron

Joined Jan 15, 2015
5,107
When replacing the cap ensure it is a Motor start rated, these are generally bi-polar electrolytic.
As to nervous about spinning it there is a slot in the rear shaft you could put a power tool on with a screwdriver bit!;)
Max.
I would start there then move on to that capacitor. Your symptoms sound just like my air conditioner did last year. A trip to the parts store and a capacitor later it runs just fine. Most places which sell home appliance parts have capacitors like the one you may need. It would be a good place to start looking anyway.

Ron
 

MaxHeadRoom

Joined Jul 18, 2013
19,981
Also if the leads are accessible, check the start switch for continuity, an open switch will give the same symptom as a bad capacitor.;)
per post #7
Max.
 
Last edited:

SLK001

Joined Nov 29, 2011
1,543
It's the cap. Down here, that's not an uncommon problem. If you want to spin the shaft, there is a slot to put a screwdriver into at the end - just turn it one or two revolutions to be sure that there aren't problems with the laminations rubbing.

I had a sprinkler pump with the exact same symtoms as yours and replacing the cap fixed it. My pump finally died after 30 years because the field laminations swelled up due to rust (outside exposure).
 

Thread Starter

joeyd999

Joined Jun 6, 2011
4,327
You guys and your screwdrivers.

Do you know how close that exposed shaft is to live 220VAC?

I told you, this stuff makes me nervous!

Yes, I turned the shaft to ensure the rotor is rotating freely without any apparent rubbing or excess friction.

But, no! I will not stick a screwdriver (or power tool) in there while the AC is on.
 

Reloadron

Joined Jan 15, 2015
5,107
You guys and your screwdrivers.

Do you know how close that exposed shaft is to live 220VAC?

I told you, this stuff makes me nervous!

Yes, I turned the shaft to ensure the rotor is rotating freely without any apparent rubbing or excess friction.

But, no! I will not stick a screwdriver (or power tool) in there while the AC is on.
OK, then we start with the capacitor. :)

Ron
 
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