Charger tripping GFCI at dock

[Ramos27]

I have a 2019 nitro bass boat with a noco gen4 charger. Earlier this spring, I fished for a couple days and plugged the boat in at the dock. Came down the next morning and the GFCI was tripped. Didn’t think to much of it, maybe just bad luck. Then last weekend I was at the lake for the weekend and tried plugging in at a totally dock and the gfci tripped again. I tried a different outlet and different cord. Still tripped. All other boats at the dock were charging fine. I loaded the boat on the trailer and plugged in the charger and it worked fine. Obviously I have a leakage problem of some sort. Any ideas on where to start troubleshooting?

[CatFan]

Simple things first. The most likely cause is moisture on your charger plug.

Give some more details. Does it work without tripping the GFCI when out of the water at home?

Do you have any interconnections between your your batteries other than jumpers between the trolling batteries and the charger? Jump start switch, noise reduction wire, charge-on-the-run setup etc.?

[Ramos27]

It works fine when it’s on the trailer regardless of where I am at.

No other interconnections between trolling motor batteries. There is a master switch on the starting battery that kills everything except the trolling motor.

[CatFan]

It works fine when it’s on the trailer regardless of where I am at.

No other interconnections between trolling motor batteries. There is a master switch on the starting battery that kills everything except the trolling motor.

36V TM?

[Ramos27]

36V TM?

Yes

[CatFan]

I would try a little experiment. With your charger plugged in at home, put a stripped wire in the ground pin of a second extension cord plugged in to the same outlet and touch it to the anode on your outboard. See if the GFCI trips.

What you are doing is simulating the lower unit in the water with a path to ground.

[Ramos27]

Just got home and tried that and it did not trip

[Fishysam]

I'm not a electrician but I found a work around for gfc, maybe catfancan tell us why it works or is a dangerous deal. Electrical safety especially on water like at the lake or in a garage where water may be dripping is important. Make your own decisions.

if ground fault trips at hotel or on a slip, if you were to remove the third prong of the cord it won't trip the circuit. At least not for apparent no reason.

[CatFan]

I'm not a electrician but I found a work around for gfc, maybe catfancan tell us why it works or is a dangerous deal. Electrical safety especially on water like at the lake or in a garage where water may be dripping is important. Make your own decisions.

if ground fault trips at hotel or on a slip, if you were to remove the third prong of the cord it won't trip the circuit. At least not for apparent no reason.

A GFCI doesn’t use the ground pin. It compares the current flowing in the hot and neutral, and shuts off if they aren’t the same. If removing the ground pin eliminates tripping, it could indicate a true hot to case fault in the charger.

Newer ones will also trip if there is a downstream ground/neutral bond, but that is pretty unlikely in a boat.

[Lou r Pitcher]

I'm not a electrician but I found a work around for gfc, maybe catfancan tell us why it works or is a dangerous deal. Electrical safety especially on water like at the lake or in a garage where water may be dripping is important. Make your own decisions.

if ground fault trips at hotel or on a slip, if you were to remove the third prong of the cord it won't trip the circuit. At least not for apparent no reason.

The ground wire in the instance above seems is doing it intended task of shunting unplanned leakage preventing a dangerous shock hazard thankfully forcing the GFCI to trip warning the user of a dangerous defective device needing service.

Intentionally removing the third prong ground wire from the faulty circuit might briefly balance the hot vs neutral currents keeping the GFI from tripping, but works only until someone walked up and in say in wet shoes touched an exposed device surface and completed the leakage to ground through their body. Hopefully the GFCI if one was available and being used that day would be quick enough to trip before their heart goes into fibrillation.

When a GFCI trips, its time to fix (repair) the cause, not defeat other safety features such as grounded extension cords.