Capacitor for Electric Pump Motor

[Maggie Glover]

I have a shallow well pump for my house and when it comes on it has begun diming the lights in the house. I can only assume that it is the capacitor going bad or the motor itself going bad. I have a healthy fear/respect for all things electrical and make my decisions for DIY on electrical things accordingly.

My question is, do you think it is the capacitor? Would you recommend I replace that capacitor and if so is there a better capacitor (soft start) that the others? If you do not think it is the capacitor, what else might it be and what can I do to test?

FWIW the pump itself is about five-seven years old and I have a 20 gallon pressure tank attached. It works perfectly other than the hard starts. Thanks, MG

[thawhacker]

You can kill the power and test the cap with a meter if your has that feature

[Palmetto Bug]

Changing the capacitor would be the cheapest and easiest remedy to try. Just match the mF rating on the label and get one the same form factor.

Before you remove the capacitor, after you have cut the power, ground across the capacitor terminals with an insulated handle screw driver to keep it from shocking you.

Does the motor try to kick on as soon as you draw water or does it take a while for the pressure to drop before the motor kicks on? If it kicks on quickly, the tank air pressure might need to be adjusted or you have a perforated bladder and the tank needs to be replaced.

[Maggie Glover]

Changing the capacitor would be the cheapest and easiest remedy to try. Just match the mF rating on the label and get one the same form factor.

Before you remove the capacitor, after you have cut the power, ground across the capacitor terminals with an insulated handle screw driver to keep it from shocking you.

Does the motor try to kick on as soon as you draw water or does it take a while for the pressure to drop before the motor kicks on? If it kicks on quickly, the tank air pressure might need to be adjusted or you have a perforated bladder and the tank needs to be replaced.

Thanks. The air tank is working properly. The tank and pressure switch allow for use before kicking on the only issue is the hard start. The whole house was built by drunk monkies in the early 70's. i really need to have my panel upgraded but that only makes this issue more important to get resolved. I think I will take a picture of it before I remove it and go ahead and buy another. They don't cost that much and from the responses and my reading it is more than likely the issue. Thanks, MG

[Palmetto Bug]

Get it fixed? Post the rest of the story when you get it resolved.

[Smilee]

If the motor is older or you have lower voltage due to distance from source you can up the capacitor 10% for better starting performance.

3 wire well pumps have a starter box with a switch in there as well.

[FLS]

There is a centrifugal switch in the motor that switches from the start winding to the run winding once the motor is up to speed anytime the motor starts. Most likely this switch is going bad. Usually if the caps are bad the motor won’t run, it will just make an humming sound and will trip the motors thermal overloads or circuit breaker. You can take it to a motor shop to be repaired, or just replace the motor. It’s an easy fix, you’ll need a new shaft seal.
Shallow well pumps (above ground) don’t have a starter box until you get above 2hp, they you’ll have a contactor / OL combo . Starter boxes are for submersibles and being phased out. Everything is inside the motor now.

[Maggie Glover]

Get it fixed? Post the rest of the story when you get it resolved.

I replaced the capacitor on Friday, it helped some but not the silver bullet I had hoped. The lights in certain part of the house blink/dim when it comes on albeit much less than before.

It is a shallow well 120v pump. The capacitor I removed did not look swollen or bad. It was strange because it was plastic. the one that replaced it looked more traditional. The circuit that it is on is within 10 ft of my fuse panel. I am at a crossroads of what to look at next. It is working as it should otherwise so it is tempting just to live with it. I am open to all ideas at this point.

I have lived here almost 28 years and this is my second pump I have replaced. This one is maybe seven years old. Not sure of their service life but I got 8-9 years out of the first one I replaced. Thanks, MG

[FLS]

FWIW I have a similar situation. Very nice house for the area and time it was built in the late 60s. Some things were done well and others were done cheaply. The plumbing is all copper pipe, but the electrical was done half assed. I’ve redone most of it, can’t believe the place didn’t burn down, wires just twisted together, no wire nuts and just a a single wrap of electrical tape. The carport lights would dim when the washing machine was running. Lots of Wadsworth Electric panels were installed in the 60 sand 70s. They were sued out of business after burning a few nursing homes down.

[FLS]

I replaced the capacitor on Friday, it helped some but not the silver bullet I had hoped. The lights in certain part of the house blink/dim when it comes on albeit much less than before.

It is a shallow well 120v pump. The capacitor I removed did not look swollen or bad. It was strange because it was plastic. the one that replaced it looked more traditional. The circuit that it is on is within 10 ft of my fuse panel. I am at a crossroads of what to look at next. It is working as it should otherwise so it is tempting just to live with it. I am open to all ideas at this point.

I have lived here almost 28 years and this is my second pump I have replaced. This one is maybe seven years old. Not sure of their service life but I got 8-9 years out of the first one I replaced. Thanks, MG

It’s the centrifugal switch in the motor. It’s dirty/ worn. The capacitor is a symptom, not the cause.

[Maggie Glover]

It’s the centrifugal switch in the motor. It’s dirty/ worn. The capacitor is a symptom, not the cause.

Would a shallow well jet pump have that? I think someone mentioned this type would not. Thanks, MG

[centurian]

Would a shallow well jet pump have that? I think someone mentioned this type would not. Thanks, MG

Yes if will have a centrifugal switch if it has a start capacitor or possibly a potential relay but i doubt that. you can buy the switch at Granger.. I would buy a new motor and be done with it for 10-20 years.

[FLS]

[QUOTE=centurian;3204745]Yes if will have a centrifugal switch if it has a start capacitor or possibly a potential relay but i doubt that. you can buy the switch at Granger.. I would buy a new motor and be done with it for 10-20 years.[/

This. Shop labor and parts will cost more than a new motor.