Shore GFCI tripping

Jul 7, 2004
8,481
Hunter 30T Cheney, KS
Anyone had a problem with a shore power GFCI tripping when you flip on the AC main switch? If I disconnect the Inverter Out neutral line from the neutral buss the GFCI doesn't trip and my A/C works. I lose the AC outlets because I'm breaking the circuit from the inverter to the outlets. The inverter and shore power share the same neutral and ground busses.
 
Jun 11, 2011
1,243
Hunter 41 Lewes
Anyone had a problem with a shore power GFCI tripping when you flip on the AC main switch? If I disconnect the Inverter Out neutral line from the neutral buss the GFCI doesn't trip and my A/C works. I lose the AC outlets because I'm breaking the circuit from the inverter to the outlets. The inverter and shore power share the same neutral and ground busses.

Without getting too far down the rabbit hole, and without actually identifying your problem, you can stop the tripping by adding an isolation transformer to your boat. It will make the load look balanced to the shore power GFCI.
 
Jul 7, 2004
8,481
Hunter 30T Cheney, KS
Thank! I will look into a transformer. I think as a quick fix I will remove the Inverter Out supply from the AC Outlets breaker and connect the shore power to supply the outlets. I understand why someone would want to power AC outlets from the inverter but I don't think the GFCI is happy with the Inverter Out and Shore Power connected to the same neutral (white) and ground (green) busses.
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
Or you could just install your inverer correctly with the switch breaking both the hot and nuetral. The addition of a iso transformer will set you back a lot more then the shore-inverter switch and take up a lot less room.
 
Jul 7, 2004
8,481
Hunter 30T Cheney, KS
Or you could just install your inverer correctly with the switch breaking both the hot and nuetral. The addition of a iso transformer will set you back a lot more then the shore-inverter switch and take up a lot less room.
The way it's wired, shore and inverter run at the same time. Shore to power systems and inverter to power AC cabin outlets. The suggestion has potential. Have to think that through. Do Hunters come with the inverters or is an owner installation?

Yeah, I choked the cost of a transformer!
 
Jun 11, 2011
1,243
Hunter 41 Lewes
The way it's wired, shore and inverter run at the same time. Shore to power systems and inverter to power AC cabin outlets. The suggestion has potential. Have to think that through. Do Hunters come with the inverters or is an owner installation? Yeah, I choked the cost of a transformer!
Lol. Yeah it's marine. Most of the inverters have the shore power wired through the inverter which is why I gave you the down and dirty solution. It's not to say that an actual problem in the wiring doesn't exist and I'm not saying you shouldn't look for the problem but it will isolate the shore GFCI. Yes my 41 has 2 isolation transformers, one for each 30amp shore power inlet. Good luck.
 
Feb 6, 1998
11,703
Canadian Sailcraft 36T Casco Bay, ME
The way it's wired, shore and inverter run at the same time. Shore to power systems and inverter to power AC cabin outlets.
This should NEVER HAPPEN!!!!!!!!!!!!!!!!!!!!!!!!!!!


Based on your description, your inverter is installed:

#1 Dangerously

#2 Improperly

#3 Not to any acceptable electrical safety standards

Rx: Disconnect inverter and re-install it correctly with a transfer switch.

Beyond the inverter a dock pedestal should have a 30A non GFCI breaker or a breaker with a trip range of at least 30mA. A standard 120V GFCI household outlet really has no place feeding a boat and the 5mA trip range can easily be exceeded with shore power cords and their high resistance plug ends especially during start up loads. Even with your inverter wired properly a 5mA GFCI feeding a 30A boat with AC is a BAD IDEA.....
 
Jul 7, 2004
8,481
Hunter 30T Cheney, KS
Thanks guys. For now I will move the AC outlet circuit over to shore power only and use the inverter as a battery charger. Then figure out how to safely use the inverter for AC on the water.
I agree. Residential outlets don't belong on docks!
 
Jun 4, 2004
392
Hunter 31 and 25 and fomerly 23.5 Stockton State Park Marina; MO
Two sources of AC power must NEVER be connected together without syncronizing the phases of the two sources. The equipment to do this is common on aircraft and perhaps other large vessels with multiple AC generators but you won't like the cost of purchasing and implementing. Follow Mainesails advise of using a source selector.
 
Jul 7, 2004
8,481
Hunter 30T Cheney, KS
Thanks again guys. I will be going out to separate the source leads tomorrow. Not much I can do about shore power except take it up with the board.
 
Jul 7, 2004
8,481
Hunter 30T Cheney, KS
Fixed! Separated the 2 source neutrals and everything works. Thanks again for the advice.