Pump breaker tripping

[Beefer]

Hi. Let me start off by saying I did a search, and seems lots of people have breakers tripping, but I'm not finding a similar situation.

We just moved into our house, and we had to have the pool brought back to life after x number of years of abandonment. It's our first pool. The pool is round and small-ish (21' dia, estimate is 6k gals). We had a pool guy come out, and he resurfaced the pool, put in a new (used) sand filter with new sand, and replaced the (unknown brand) 1/2hp pump with a Hayward 3/4HP pump, among other tasks.

The pump is plugged into a GFCI outlet outside, and then the circuit is protected by a 15amp breaker. The pump says it has a max draw of 10.1(?) amps. After the second day, we noticed the breaker was tripping. It would trip after a random amount of time, sometimes on start-up, sometimes after anywhere from 10 minutes to 2 hours of use.

My first thought was a bad GFCI outlet, so I replaced that. No go. Second was the breaker - replaced that and still no difference.

As the pool was just completely cleaned, and the pump is new, I'm discounting the possibility of a jammed impeller (although I haven't checked). To the best of my knowledge, the pump has not gotten wet. The skimmer basket and the basket at the pump are clear/debris free.

Unfortunately, we have not been able to contact the pool guy, as he has been on vacation. Does anyone have any idea of what I can be checking or looking for? I'm handy, and have a decent set of tools, so I'm not too fearful of digging in.

Thanks in advance!

 

[CraigMW]

So, this is a 120V pump that is plugged into a standard (3-prong) GFCI outlet, right? So, when the pool guy installed this, how long did the pump run before you started getting the breaker to pop? Are there any other circuits connected in line with that GFCI outlet? Lastly, is the GFCI outlet tripping, or is it just the breaker shutting down? If the pump is connected to another outlet, do you see the same breaker shutdown issue?

It sounds to me like the GFCI is not tripping, just the 15A breaker. If this is the case, it could be that the breaker is rated too low for this pump. 10.5A would seem to be okay on this circuit, as long as the pump is the only load. The current draw may be higher on startup, and that could lead to the breaker shutting off the circuit, but this would really only likely be on startup. It could definitely be an issue with the pump motor. When turned on, does the pump move any water? Do you see any pressure on the filter's pressure gauge?

 

[JohnT]

What does the pressure gauge on your filter read? What model is the pump?

 

[Beefer]

Hi JohnT. Thanks for the reply. Figured it out with your help - it's the UG wiring. Brought out an extension cord, and the pump is going fine and strong. All above ground wiring is checking out fine, but as soon as I bring the UG wiring into the loop, it trips. Must be a short in there somewhere.

Looks like a call to an electrician is in order for tomorrow.

Thanks a ton!