Pump Blowing Breaker Instantly

[Exchemist]

I just started opening the pool for the season. Everything was working fine when I closed in the fall. The equipment is fairly well protected in a small pump house, so I leave the pump out over the winter. All the equipment was installed well before I bought the house. I believe everything is between 12 and 15 years old.

The breaker trips instantly (less than 1 second) after power is applied. If the pump is unplugged, the breaker does not trip. So, the wiring and timer are fine. The pump impeller turns freely.

Does this sound like a short in the motor? In your opinion, is it worth replacing the motor or does it make sense to just get a new (and maybe more efficient) pump? The filter seems fine, but the multiport valve is binding a bit and it does leak a few drops (literally) a day.

Thanks!

 

[Tim23]

I can't tell you what would be a better choice (buy motor or pump) but I can tell you that most of the time when you have a "dead short" which is what you have, that its easier to find then something that runs a while and then trips a breaker. Are you able to do some diagnosing or feel comfortable checking the motor itself?

If so I would take the cover where the power cord enters the motor off . Look to see if there is anything burnt or unplugged. I can tell you that ants can build a nest inside and cause a short. Even a spider or some other insect can get between contacts and cause a short. Make sure you unplug the motor when making those checks. It doesn't take much in the right place for it to cause a short. Check to see if ground wire or one of the wires that come from the power cord hasn't rubbed against the case of the motor and just from the weather change it has touched metal. Hope this helps and if you have a question just ask. If you want to take a pic of what you see inside that might help someone point you in the right direction.

Tim

 

[Exchemist]

Thanks Tim23 for the suggestions. I was able to pull off the cover on the pump (after unplugging it). However, that end of the pump is very close to the wall of the pump house and it's hard to get a good look at the connections.

There was about a tablespoon of white powder at the bottom of the cover. A close look with a mirror revealed a metal ring just touching the connections to the capacitor. Everything else looks fine to me. It looks like the capacitor burst and the ring was part of its pressure release. The white powder seems to be from the capacitor.

So, it looks like I need at least a new capacitor. For completeness, I am getting quotes for a new motor and an entirely new pump.

 

[Tim23]

That sounds like you found the problem. Most likely the cap froze or just failed. A lot of the time when a cap bursts like that its from a leak and moisture gets inside and over time it shorts it out. Sometime when they just fail they will expand and leak. For what the cap should cost you it would be worth a shot to see if it works. Give it a try but it could be hard to find. Good luck,

Tim