My GFCI is tripping on my houseboat

texasvet54

Petty Officer 1st Class
Joined
Nov 5, 2010
Messages
267
Help Please!!!

I have a 52' factory built Three Buoy's Sunseeker houseboat with an aluminum hull. My dock was recently re-wired with individual GFCI breakers on each slip and when I connect to the receptacle for my slip the GFCI breaker tripped. Prior to the installation of the GFCI breaker, everything was fine.

Here is what I've done so far:

1. I disconnect my power cable from my boat and connected it to the dock source and breaker doesn't trip.

2. I placed my on-board power panel "Dock-OFF-OnBoard" power switch to the OFF position with all of the breakers turned off and the GFCI breaker trips.

This is pretty perplexing because in the OFF position with no load, I would have thought that the GFCI breaker would not have been providing any current.

My next step is to trace my wiring to the "Dock-OFF-OnBoard" switch from my power cable connector and disconnect the wiring from the switch. If the GFCI doesn't trip, I'll proceed further down the line.

I wanted to start this project this weekend and I was wondering if anyone has ran into this before and can give me some guidance?

Thanks,
Texasvet
 

JASinIL2006

Vice Admiral
Joined
Feb 10, 2012
Messages
5,524
Have you tried connecting your boat to a different GFCI receptacle? We had a GFCI breaker in our house that tripped all the time, and it turned out it was just defective... If you connect to a different GFCI receptacle and it throws the breaker, then you may have a ground fault in your boat somewhere.
 

Thalasso

Commander
Joined
Jan 18, 2011
Messages
2,876
Help Please!!!

I have a 52' factory built Three Buoy's Sunseeker houseboat with an aluminum hull. My dock was recently re-wired with individual GFCI breakers on each slip and when I connect to the receptacle for my slip the GFCI breaker tripped. Prior to the installation of the GFCI breaker, everything was fine.

Here is what I've done so far:

1. I disconnect my power cable from my boat and connected it to the dock source and breaker doesn't trip.

2. I placed my on-board power panel "Dock-OFF-OnBoard" power switch to the OFF position with all of the breakers turned off and the GFCI breaker trips.

This is pretty perplexing because in the OFF position with no load, I would have thought that the GFCI breaker would not have been providing any current.

My next step is to trace my wiring to the "Dock-OFF-OnBoard" switch from my power cable connector and disconnect the wiring from the switch. If the GFCI doesn't trip, I'll proceed further down the line.

I wanted to start this project this weekend and I was wondering if anyone has ran into this before and can give me some guidance?

Thanks,
Texasvet

Have you tried using another shore power cord?
GFCI outlet tripping offline is caused by different current on the hot and neutral wires going to the boat.
Make sure everything is individually turned off. Do you have a battery charger on board?
 
Last edited:

Boydski

Seaman Apprentice
Joined
Mar 21, 2008
Messages
46
As mentioned above, GFCI tripping is caused when there is a mismatch between the current flowing through the hot and neutral wires, which usually indicates some of the current is coming back via the ground wire. That can be caused by corrosion in the neutral wire (white) connections, poorly wired/grounded components in your boat or even stray currents coming via your aluminum hull. Your hull should not be used as a return path for electricity and should be isolated from all electrical components.

I've been troubleshooting a similar problem for many months, which occurred even when my ground wire was disconnected (had me scratching my head). I noticed last week, the problem mysteriously went away and then returned this weekend. The neighboring boat had been gone all week, then returned, so like a bad boat neighbor, I went over and turned off his non-GFCI power momentarily and my GFCI stopped tripping, so in my case at least, the neighboring boat is "hot" and causing the issue.
 

wrvond

Chief Petty Officer
Joined
Mar 2, 2010
Messages
597
The only thing that has changed is the outlet on the dock. That is the most likely source of the problem. The reason it doesn't trip with just the umbilical is it is still an open circuit. I'd purchase a simple GFCI tester such as one from Lowe's for $8.00 and check the outlet first, then the umbilical. If both those test good, then start looking for problems on your boat.
 

MH Hawker

Vice Admiral
Joined
Jul 13, 2011
Messages
5,516
being as the marina was recently wired i would contact them and let them sort it
 

texasvet54

Petty Officer 1st Class
Joined
Nov 5, 2010
Messages
267
Thanks for all of the advice. I'm going to look at buying the GFCI tester & heading out there tomorrow.

I was told today that several boats that used to be just fine, like mine, we're tripping the new GFCI breakers and an electrician had to install an isolation transformer to solve the problem. I'm gonna to have to do some research on that one.

Thanks,
Texasvet
 

texasvet54

Petty Officer 1st Class
Joined
Nov 5, 2010
Messages
267
Phooey!!! After looking on the Lowe's and HD websites, apparently the GFCI testers that they sell are only for 120v. My boat has 220VAC 50A service.

Anyone know of a source for reasonably priced 220V tester?

BTW, I might add that upon initial installation, the GFCI breaker was tripping without my hooking up to it. The electrician said that it was my boat and I took him down to my slip and showed him that I wasn't connected to the dock connector. I was told that he put a new breaker in and checked his wiring.
 

texasvet54

Petty Officer 1st Class
Joined
Nov 5, 2010
Messages
267
Have you tried using another shore power cord?
GFCI outlet tripping offline is caused by different current on the hot and neutral wires going to the boat.
Make sure everything is individually turned off. Do you have a battery charger on board?

I have a batter charger, but it is disconnected. I'm hoping to TS some tomorrow & I'll post.

Thanks
 

texasvet54

Petty Officer 1st Class
Joined
Nov 5, 2010
Messages
267
Today, I connected my 220VAC Hubbell connector to the dock power and confirmed that the GFCI tripped.

I then did the following:

1. I disconnected all of the wires from my breaker panel selector switch (Red,Black,Green,White)
2. I turned the GFCI breaker back on and it didn't trip. This should indicated that the trouble is not in my cable or on-board through-the-hull connector.
3. I connected the green ground wire back to the breaker panel and the GFCI didn't trip.
4. I then connected the Neutral wire (white) to the power panel and the GFCI tripped.

So, the 220VAC feed (Back and Red) were not connected and the GFCI tripped.

I'm not a licensed electrician, but I do know a whole lot about power and current from my career as an Electronic Technician so here's my question:
If my 220VAC feed (black & red) were disconnected, how did the GFCI detect a loss of returning current and trip?
Could my GFCI breaker that was installed by the contractor be bad?

Thanks,
texasvet
 

frantically relaxing

Senior Chief Petty Officer
Joined
Nov 19, 2011
Messages
699
Ok so the neutral trips the GFI with the 2 hots disconnected... this means either (a) the GFI is bad, or more likely, (b) you're boat's neutral is picking up DC voltage from the boat somewhere thru the grounds. Remove ALL the cables from all of your batteries, so no cables are connected to anything. If you have any solar power, disconnect that.

Then see if the neutral-only trips the GFI...
 

vans

Petty Officer 3rd Class
Joined
Sep 26, 2004
Messages
78
I seem to be replacing 120v GFI's often, especially ones on exterior of homes, phantom tripping is the norm. Try a GFI breaker.
 

texasvet54

Petty Officer 1st Class
Joined
Nov 5, 2010
Messages
267
Update:

I remembered that I had a small breaker panel under my instrument console. I removed it and took a look inside only to find that the neutral buss and the ground buss were tied together. I removed a screw that connected the two and I was able to get some of my electrical system working.

Turning on the Air Conditioner trips the CFGI as does turning on a couple of the overhead light breakers.

Tomorrow afternoon, I'm going to remove every connection from the power panel and start adding items back on until the CFGI trips in hopes that I'll find another place on my boat where the ground and the neutral are connected.

texasvet
 
Top