Hayward Superpump 3/4 HP tripping GFCI

[whitepelican]

Hello all. I am wondering if anyone has any advice or testing ideas for me on my pool pump. I have a 5 year old in-ground vinyl-liner pool with a 3/4 hp Hayward Superpump. Haven't had any issues with the pump in the past five years. But when attempting to start up the pump for the first time this year, it immediately trips the GFCI breaker (in the panel in basement). It's been a wet spring (mostly snow), but the motor appears to be dry inside and out. I switched the wiring at the breaker panel to test it on a different gfci breaker (used for the hot tub) and it immediately tripped that one also. When I disconnect the wiring at the motor, it does not trip the breaker. So, I thought I would further test the motor by disconnecting the wiring and hooking up my own plug (and switching it over to 115V instead of 230V). When I plugged it in to any of the GFCI outlets on the outside of my house, it immediately tripped again. So, I took the motor inside and plugged it in to a non-GFCI outlet and it runs perfectly.

I guess my question is, does this mean the motor itself needs replacing, or is there something else I'm missing that could cause it to work again on the GFCI circuits?

 

[Texas Splash]

As we know, GFCIs are much more sensitive to heat and moisture. With all the tests you've performed, it does sound as though something in the motor itself is causing the issue. Since it appears to be dry, I wondered if it wasn't just stuck a bit inside the casing causing excessive heat. After running the motor on a non-GFCI circuit, did you try it again on the GFCI line to see if it would still trip?

 

[tstex]

Has anything changed [grounding wires, new breaker, something else added to pool panel, other electrical devices in the area, etc] since when it ran well last year and to now when it's not running on the equipment pad.

As noted by Pat, GFCI's for pumps are rated, at max, for 5mA's to trip the GFCI breaker, some even 3-4mA's. the fact that you've changed GFCI breakers; tey both tripped and a std breaker did not, it's something w the sensitivity to grounding out the GFCI. As Past stated, run the pump [carefully] on the std breaker to see if heating it up and thus drying it out, has anything to do w it being able to run on the GFCI properly? try this and post back