When we plug into 30 amp or 15 amp shore power, there are no problems with any protective non GFI devices {breakers}. We have recently moved to a new slip in our Marina that has GFI breakers on the Shore Power and now everytime we plug the power cord in, it trips the GFI breaker. I have turned the DC main off and any breakers on that panel. I turned off all the breakers on the AC panel. When I turn the main AC breaker on, it trips the GFI in the shore power {with none of the AC breakers in the on position}. There is a Xantrex Freedom 20 Inverter/Charger on our Hunter 356. This problem has occurred on 4 different 15 amp plugs fed by the Marina shore power. What could be causing this?
GFI Shore Power Trips
- Thread starter t054281
- Start date
Think I know
This will trip gfi units
Do you have a "reverse polarity " light on your panel?
This will trip gfi units
I always told my customers when they saw a reverse polarity light, pretend it equals to electrocution. They listened. Once I sold a 33 which at the marina worked fine on a 30 amp as well as 15 amp service. They went to visit a friend at a newly built marina and the reverse polarity light came on. They disconnected immediately and did not go into the water or touch any metal on the dock and immediately left. Their friend advised the marina which did nothing which included other complaints. The boat tenant contacted the county inspector's office which investigated quickly and found that the wiring on that dock was installed by an idiot who was not an electrician and of course the rest is history.
Another possibility would be if you have the neutral and ground connected together in your AC panel AND it's also connected on the dock panel. This will trip GFCI breakers too.
others mentioned the reverse polarity which is easy to check so do that first. if that checks out then clearly there is current going through the ground circuit. GFI protection has to see the same current on hot and neutral. When they don't match (even a little) it trips. Since electricity HAS to return (think of it as an incompressible fluid) or it can't get in in the first place that would mean the ground is carrying some current. The neutral and ground are not supposed to be connected in the shore power circuit. If you have an inverter or genset there should be a connection at the source but those sources should be disconnected at the source selection switch. So check the continuity (disconnect from shore power first and turn of all other sources onboard) between neutral and ground. If there is not a very high resistance with the source selector switch (transfer switch) in the shore power position then that is your problem.
Now if you don't have a source selection switch to isolate the onboard AC power sources......... or one of the AC appliances does not have a CB......
Now if you don't have a source selection switch to isolate the onboard AC power sources......... or one of the AC appliances does not have a CB......
I'm all ears on this issue as I have the same problem. For the past several years I've been at a condo dock with several boats on the same GFI protected string of 15A outlets with no problems. This spring I moved to a private dock with my own GFI outlet. Now, when I turn on the main AC breaker with all other breakers on the boat off, the shore GFI trips. Same cords, connectors and pigtail as before. I didn't see the reverse polarity light come but I'll have to look at the wiring diagram to see if it will will indicate even if the main breaker is off. The boat is currently on the hard getting bottom paint, but will be back troubleshooting in a week or so....
Gary
Gary
Neutral bonding
But, the inverter disconnects the neutral to ground bond when shore is live. That is a function of the internal transfer switch.
Here is what a reverse polarity light does:
It connects a light between the neutral and ground legs, which typically runs about 10ma of current.
The gfi units are set to 5ma trip.
Now, without a bona-fide reverse polarity issue, you shouldn't have any current between N to G.
So, I suspect that you have an on board wiring issue, or, it is possible that the shore wiring going to the gfi is reversed.
A gfi won't trip from reverse polarity, as long as there is no ground leaf age.
The shore neutral is ground bonded before the gfi, so the gfi is only looking for unbalance after that point.
So, here is an easy test:
Disconnect the reverse polarity indicator lamp.
Does the shore breaker still trip?
If not, then you've got a bona fide power reversal, and the light is tripping the gfi
Good luck!
Ok, it is likely that the neutral is bonded to ground on the output of the inverter, because this follows ABYC code.
But, the inverter disconnects the neutral to ground bond when shore is live. That is a function of the internal transfer switch.
Here is what a reverse polarity light does:
It connects a light between the neutral and ground legs, which typically runs about 10ma of current.
The gfi units are set to 5ma trip.
Now, without a bona-fide reverse polarity issue, you shouldn't have any current between N to G.
So, I suspect that you have an on board wiring issue, or, it is possible that the shore wiring going to the gfi is reversed.
A gfi won't trip from reverse polarity, as long as there is no ground leaf age.
The shore neutral is ground bonded before the gfi, so the gfi is only looking for unbalance after that point.
So, here is an easy test:
Disconnect the reverse polarity indicator lamp.
Does the shore breaker still trip?
If not, then you've got a bona fide power reversal, and the light is tripping the gfi
Good luck!
I finally was able to find the problem with my Xantrex Freedom 20 Inverter tripping the shore power GFI protected feed. It turns out the the out- side of the inverter was wired incorrectly on the AC panel. The neutral from the shore power, neutrals from all the AC boat circuits and neutral from the AC-out from the inverter were tied down on the same bus-bar. I had to separate the AC circuit neutral not fed through the inverter {hot water tank} and ensure this was tied through the AC shore power neutral. All the other AC circuits {neutrals} were tied to the AC inverter out neutral on a separate bus_bar. All is good now. Here is the link to the documentation I was sent; page 32 option 2 http://www.xantrex.com/documents/Discontinued-Products/FreedomMarineOwnersManual.pdf