Why will lower voltage capacitor work my pump?

[mas985]

That sounds more like a bearing issue than a capacitor issue. When bearings start to fail, they create extra load on the motor which tends to make the motor overheat and trip the thermal limiter switch. After the motor cools off, the thermal limiter will then reset and the motor can then be turned on again. When the bearings get really bad, the motor will have difficulty spinning up to speed. Of course, any mechanical interference within both the motor and pump wet end can cause the same symptoms.

As to why the lower voltage capacitor seems to work, that could be due to extra torque created by this particular capacitor. Does it have the same micro-farad rating as the original?

[Albgoblue]

The original 370 vac capacitor has a 30 MFD. The lower voltage capacitor says 124-149 MFD on the side. Does the higher mfd create greater torque? If the bearings are going, is there anything to do other than getting a new pump? Should they go in less than 3 years? Also could the possibility of all of this be happening because I'm not getting enough electricity to the pump? Could that be the reason the lower capacitor works but then the pump is shutting off due to not enough power? I'm just trying to think outside the box.

[mas985]

Does the higher mfd create greater torque?

Yes, it creates a larger phase shift between the primary and start windings so start torque is higher but so is start current so you risk burning out the starter winding's.

If the bearings are going, is there anything to do other than getting a new pump? Should they go in less than 3 years?

If the pump seal fails, which they do, the water can leak into the motor and cause the bearings to rust. But 3 years is a short time although I have helped people with shorter times too. There are several things you can do.

1-Replace the bearings. You would need a bearing puller to do this.

2-Replace just the motor. Not very hard to do.

3-Replace the entire pump. More expensive than 1 & 2 and just about as hard as #2.

Also could the possibility of all of this be happening because I'm not getting enough electricity to the pump?

If the voltage is too low on an induction motor, it will draw more current and the thermal limiter switch should shut it off so it will cycle on and off which are similar symptoms to a bad bearings but the voltage would have to be very low. Have you measured the voltage?

[Albgoblue]

I have a tester and it showed it is pulling in 120 volts. The pump appears to be wired for high voltage. If the case is that the pump is wired for high voltage but only low voltage is going to the pump, how did it work for 2 years? I have a friend who is better at electricity than I am to confirm that only 120 is coming into the pump.

[mas985]

Most single speed pump motors can be wired for either 120v or 240v. Normally, a motor will pop a breaker not run at all if wired incorrectly.

[Albgoblue]

It appears my pump is fixed and the issue solved. There is indeed only 120 volts coming into the pump and the pump was wired for high voltage. I switched the pump wiring to low voltage and everything is now running great with the original 370 vac capacitor. The pump ran all night and has not shut down at all. The question is why did it run for 2 years wired incorrectly and why did the pool people who installed the pump not switch the wiring to the correct setting? I guess we do not need to answer that. Anyway, thanks for your responses and help. I am happy I have a running pump again.

[PoolDoc]

There is indeed only 120 volts coming into the pump and the pump was wired for high voltage. I switched the pump wiring to low voltage and everything is now running great with the original 370 vac capacitor. ---- The question is why did it run for 2 years wired incorrectly and why did the pool people who installed the pump not switch the wiring to the correct setting?

For the record -- and for all the other people who may read this thread in the future -- I'm very doubtful that the pump actually DID run for years wired 240V, but supplied 120V. As far as I know, with most pool motors, this is not possible.

I'd guess that somewhere in the assembly and repair process, some wiring got switched around.

[PoolDoc]

membership updated.