15 year old Coleman Spa trips circuit breaker

[ericnmon]

Horizon 400 series Coleman Spa, bought it used 10 years ago, and had it professionally installed including new service to my existing house panel.
Over the last two or so years the GCFI circuit breaker which is located on the house panel would trip every few months. Over the last several weeks it became more regular and now it trips after just a few hours.
(It seems to have gotten worse as our summer weather got hotter and hotter, coincidence???)
I have tried everything to diagnose the problem, like disconnecting the ozonator, the blower, the number two pump, the heater(which I replaced 3 years ago), and finally had a new circuit breaker  professionally installed.
The electrician also checked the wiring coming from the main pump, indicating the amperage looked alright.
 Finally I had spa repair person who has worked on Coleman's over to double check all these things and more, including all connections inside electrical panel etc. After an hour or so he gave up and said he'd call back if he could come up with an idea of what may be wrong. I haven't heard back from him yet. Anybody out there hazard to guess what else should be checked? It is stumping everybody so far.
We love this tub, it is beautiful redwood which I've kept up through the years, and the shell is also in excellent condition, wouldn't want a new one even if we could afford one. Help!   

[Chas]

Disconnect the wires right at the tub, safely secure the wires, and then turn the breaker back on. See if the GFCI trips - if so, you have water in the conduit, a nicked wire, or other issues with the wire from the breaker to the tub. You may have to leave it overnight - especially if you have automatic sprinklers hitting the area...

If it doesn't trip, reconnect and start by simply disconnecting components on the tub itself: Start with Ozone, then blower. Those are common trouble-makers. Next is the heating element, and that may be a bit more tricky.

HTH

 

[kcsparky]

Please be very careful!!  A tripping GFCI indicates a ground fault and could lead to an electrocution situation.  This fault could be in a number of areas.  An old motor could be the problem as they are notorious for tripping GFCI's due to breakdown in the insulation.  Chas is on the right track with initial troubleshooting. Turn off power to the tub at your circuit breaker panel and then turn off the GFCI.  Disconnect the feeder wires to your tub at the tub control panel and make sure that they are isolated from each other.  Using a good multi-meter, select the Ohms setting and check for continuity between the ground (green or bare) wire and each hot wire as well as between the neutral (white) and each hot wire by touching a probe on the appropriate ground lug and each terminal where outgoing wires are landed on the bottom of the GFCI breaker.  If you read any continuity, replace the in ground power feeders to your tub.  If there is no reading ("OL" on most meters) the problem is in the tub.  If you have any continuity reading between the motor power (hot) terminals and ground, the fault is in the motor and it should be replace due to dead short.  Anything further without looking at a schematic for this tub would be shear speculation.  If both of those tests come up negative, I would contact a qualified spa repair rep. or a licensed electrician with a good troubleshooting background and have them investigate deeper into a ground fault situation at the tub.  I would not recommend using your tub until this is identified, repaired and test run.  Hope that this helps.

[ericnmon]

Thank you both very much for the tips and advice, I will proceed
with these checks and let you know what I find.