I am having a problem with my GFI breaker tripping when I try to use my boat lift that was installed last fall.
The lift manufacturer suggested that the voltage could be too low at the remote control panel. I upgraded the wire from the main panel to the controller (310 feet) to a combination of 100 feet of #6 AL feeding 210 feet of #8 cu. The remaining wire from the controller to the lift motors (two 3/4 hp, 240V) is 50 feet of #12 cu that is run in PVC pipe along the lake bottom (there are no splices between the controller and the motors). I measured a loaded voltage (lift running lifting the boat, 11 amps) at the controller (not the motors) of 242
+/- 13 volts using the 400 volt scale on the meter and 243 +/- 5 volts using the 200 volt scale (measuring leg to ground and adding. The meter has a better accuracy on the 200 scale). The unloaded voltage was 246 volts. Based on this, I am hoping this is not a voltage drop issue.The remote control manufacturer says it could be 1) a voltage issue or
2) moisture in the motor due to recent heavy rain. The motors are designed to be exposed. There are drain holes which are plugged (installer forget to remove them). Not sure how to check this.After resetting the breaker, the lift will sometimes go up and down. Other times, it will trip the breaker as soon as I push the button. The subpanel breaker is 15A which was what the manufacturer recommends. The main breaker is a 50A GFI.
Any suggestions on how to troubleshoot this problem?