Hello folks, hoping to get some help.
Running a spa pack with air switches, 2 speed pump, the slower speed runs while the tub is heating up, then kicks off when it hits the desired temp (at full setting on the spa pack usually between 102 and 105 degrees f.), then kicking back on and off as the thermostat dictates.
The Problem: The spa keeps tripping the GFI. As far as I can tell from monitoring the situation, it's happening right when the water hits the desired temp and the pump shuts back off from the low speed.

I had an electrician friend test the GFI and he says it's fine at this point.

happy to answer any specifics.

much thanks in advance.

Ajax.