Hot tub pump tripping GFCI

[Jacuzzi Jim]

so say after 2 more weeks it still hasnt tripped with the pump disconnected.  What do i do at that point?  Obviously plug back in to see if it happens with it plugged in again, but what other trouble shooting is there?  Can i take any electrical readings at the pump terminal or anything?

   You can put a volt meter on it and confirm it is sending 220 to the lead when you press the pump btn.  But if it was likely tripping during the purge cycle when the pump was hooked up it won't matter.    I would say plug it in, how long has it been, 10 to 12 days?   I might give it another week.  Then run normally and see if it trips.   After that hard to say if it trips again just short of replacing the board not much left to try.    Spa is now heating and running normal?  If so again my thoughts are still pump 2. 

[gmdodt]

Yea, ill report back after another week or two of leaving pump 2 disconnected.  When i reconnect it ill take some readings.  The service guy had a megger the lines into the break from the tub and there was no material leakage (many weeks ago)...just weird

[gmdodt]

So it is now July 5, and I still only have the primary pump plugged in and it still hasn't tripped in over a month a half.  I suppose I will plug the pump back in in a few days and see if it trips.  What are peoples thoughts on whether it is the pump, board, or possibly something else?

[Jacuzzi Jim]

 90% it's pump 2

[gmdodt]

is a bad or failing capacitor the possible culprit?  If so, thats replacable on these pumps, no?

[Jacuzzi Jim]

 You can try it, but the hassle and time you have put into this alread just buy a new pump.  With Murphy's law in affect, you will spend money on the capacitor and it won't matter.  That said, you can spend money on a new pump and the same outcome might occur, but the odds would be worth it.       

   Personally, I would take the chance on a new pump.   

[gmdodt]

Your advice is well received and I understand - on most occasions I would agree and go out and just buy a new pump; however, these things are running $300-400 so its a painful pill to swallow if it turns out not to be the issue, or if its just a cheap capacitor.  Undecided on what I will yet.  still havent plugged it in.  Do you have any idea how to figure out what capacity I would even need?  Or places you would suggest to buy the pump from assuming I am going to do the labor myself.

[gmdodt]

Update

Well yesterday I powered the tub down. It still hadn't tripped with pump 2 unplugged. I took the capacitor out and tried to find a new one online. Was hard to find an exact match. I ended up testing the capacitor and it read 220microfsrrad when the capacitor is rated for 189-228 so it seems fine. I put it back in and took the back cover off the pump. The shaft spins freely and I ensured all the connections we're on tight. Reassembled. Turn tub on and measured voltage to pump both pumps read the same..120 each leg. Measured amperage..all 4 were close..3 of the 4 legs were in the 7.3amp range but the fourth leg (on pump 2) read 6.8. I can't imagine that's a problem..but maybe? The tub, with both pumps on high and the heater going only measured 30-31amps on each leg of the wire connecting to the control board (clamp on multimeter). Also, pump 2 starts immediately and no humming noise

Nonetheless, put all back together and am going to see if the old problem persists..will report back either way. At this point, nothing seems to be wrong with the pump even tho the tub doesn't trip when it's disconnected.

[gmdodt]

So as an update - Hot tub is still randomly tripping -

Today I replaced the capacitor (same ratings and everything) on Pump 2 (which is the pump i had disconnected for two months and it didnt trip). 

Replaced it, powered up, worked fine.  Went out tonight to check chemicals and I went to push JETS to turn it on and it instantly tripped.  This has only happened one other time since having the tub (probably 6 months ago).  Reset the breaker, then it worked perfectly fine...pushing JETS as fast as possible trying to get it to trip and it wouldnt.  Weird.

Maybe this gives some insight into the potential problem.  Still could be pump 2 since it didnt trip at all when it was disconnected...but maybe its a main board issue if the hot tub is tripping immediately when being powered up.  Any other thoughts?  It cant be gauranteed when the tub is tripping most of the time because its random and we arent in it/using it.  Just thinking the two may be related..