dock GFCI trips out

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PatSea

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I changed marinas this year after being at the previous marina for the last twelve years. When I arrived at my new marina and plugged in my shore power cord I tripped the breaker instantly. (I have never tripped a breaker in the last twelve years, but then I don't think I had a GFCI breaker on the power pedestal.) This is a 20 amp breaker with integral GFCI. I chased the problem this past weekend but unfortunately I did not have any meters with me. Here is most of what I know so far:

1.Most of the time I can trip the dock pedastal breaker (20 amp with GFCI) with all boat branch circuits turned off. Most times when I turn on the main breaker in the boat the GFCI trips instantly, so this is not an ampacity problem. I'm convinced it is a ground fault problem, most probably somewhere on my boat (at least that's the assumption I'm working on at this point.)

2. The marina owner changed out the breaker on the power pedestal with a new 20 amp GFCI type breaker and the problem persisted, so I don't think it is a defective breaker.

4. I plugged in to my neighbors' docks GFCI power pedestal. I was able to turn on my main breaker and run a fan for about 20 minutes before it tripped the breaker. I did this several times and it repeated. Seems like this particular GFCI breaker may be a little less sensitive.

5 At one point when I was chasing this I was able to turn on the branch circuit breakers on my boat one by one. The breakers for the A/C, battery charger, port outlets and starboard outlets would trip the pedestal GFCI breaker instantly. A few of the other circuits would not trip it.

6. I used an almost new cord from a friend and had the same problem. At this point I have ruled out the power cord.

7. I have inspected both sides of the inlet connector on the side of the boat. It looks OK. I don't see any evidence of heat or arcing, the connections are tight etc.

As the "new kid on the block" I talked to a few of the other boaters who have been there a long time. Apparently this nuisance tripping has been an ongoing problem.

Since I got home yesterday I have done some research on the internet. There seems to be quite a lot of information out there about this situation in marinas. Some of the information is conflicting which is not surprising.

I read several places that it is difficult for even a properly wired boat with multiple circuits to not exceed the 5ma ground fault leakage that is the trip point for these breakers. To prevent nuisance trips but still provide adequate protection new boats are required to have an ELCI (Equipment leakage circuit interrupter) which protects the entire boat but is set to trip at 30 ma.

Any suggestions on a procedure for determinng the source(s) of this problem?
 
I can't tell you how to fix your boat without looking at it and making some tests, but it does puzzle me that your boat is connected to a 20 amp circuit with a GFCI breaker. This is something you might have at home for a trailered boat, but all the marinas I've stayed at have 30 or 50 amp twist lock receptacles with standard (non-GFCI) breakers protecting the circuits. Your boat should have its own GFCI protection for the receptacles and possibly some other circuits, much like a house would.

The pedastals usually have a 20 amp GFCI protected circuit in addition to the circuits for boat power to be used for tools, lights, compressors and such. I've tripped the pedestal GFCI receptical by dropping an extention cord into the water (not on purpose of course), but never in normal use.
 
What kind of cord are you using to get to 20 amps? Is your main breaker 30 amps on your AC panel?
Are you using any kind of adapter at the pedestal?
Forgive me I haven't seen anything smaller than a 30 amp pedestal in years.
Bill
 
I am using a standard 30 amp three prong twist lock cord with no adaptor. The pedestal is like any other I've seen except it has only a 20 amp GFCI breaker. My boat panel main breaker is 30 amp. I don't draw anywhere near 30 amps, so I don't think the 20 amp restriction will be a problem. The problem is the fact that my boat is served through a 20 amp breaker with an integrated 5 ma GFCI . I also have several on board GFCI receptacles.
The previous marina I was at for about 12 years had a standard 30 amp breaker without integrated GFCI.
 
Something is not right here. It makes no sense to have a 20 amp breaker protecting a 30 amp circuit. I think you need an electrician to check all this out and figure out a solution.
 
quote:
Originally posted by rawidman

Something is not right here. It makes no sense to have a 20 amp breaker protecting a 30 amp circuit. I think you need an electrician to check all this out and figure out a solution.

Click to expand...


+1 Tell the marina you will bring in an electrician and cover any cost to repair your boat but if he finds the problem is in with their feed you would want them to pay for the repair. You might be surprised at how quick they find a solution!
 
My opinion is the marina does not have adaquate power to supply 30 amps to each dock, so they limit it to 20 amps by installing 20 amp breakers at each sick. But again, I don't think my problem is caused by drawing too many amps (main. Breaker trips with all boat circuits turned off). The problem is related to the ground fault interrupt or (GFCI). I don't think the dock breaker should have a GFCI. does anyone know what the electrical code requires?
 
At my house the breaker that feeds my shorepower is a 20 amp breaker. That's because the previous owner used wire that was too small for the run. I have the standard 30 amp receptacle on the pedestal. I have never had an issue. Even when I lived on the boat during a major home renovation, the breaker never popped. I routinely have the AC on along with the fridge. since I know the wire and circuit isn't 30 amp I always shut either fridge or AC down when using the water heater. The 20 amp breaker isn't the issue unless he is firing up everything on the boat at once and it doesn't seem like he is.
 
I had the same problem at an inland lake marina which switched all breakers over to GFIC to conform to a commercial building code (not for a marina). After much review and help from the South Carolina Marina Association, it was determined that the breaker(s) sourcing a 30 AMP boat with their own internal GFIC outlets should not have dockside breakers with GFIC. The electrician installed a normal breaker and that eliminated any circuit tripping on the boat.
 
I had the same problem at an inland lake marina which switched all breakers over to GFIC to conform to a commercial building code (not for a marina). After much review and help from the South Carolina Marina Association, it was determined that the breaker(s) sourcing a 30 AMP boat with their own internal GFIC outlets should not have dockside breakers with GFIC. The electrician installed a normal breaker and that eliminated any circuit tripping on the boat.
 
Have the marina swap out the 20amp GFIC outlet to a 20amp non-GFIC outlet. If that solves the problem, the marina foots the bill. If it doesn't resolve the issue, then you pay the bill.
 
I have swapped out my shore power cord to a 30 amp breaker without GFIC and no electrical problems. In fact, for the last 12 years at my previous marina I had no electrical issues on a 30 amp standard breaker without GFIC. It's only when I'm on a GFIC type breaker that I have a problem.
 
quote:
Originally posted by PatSea

I have swapped out my shore power cord to a 30 amp breaker without GFIC and no electrical problems. In fact, for the last 12 years at my previous marina I had no electrical issues on a 30 amp standard breaker without GFIC. It's only when I'm on a GFIC type breaker that I have a problem.

Click to expand...

Are you saying that you fixed the problem or is this troubleshooting information?
 
My feeling is that if a GFCI breaker trips but a non-GFCI does not, you still have a problem; those GFCIs are there for a reason.

The AC starting load might simply be higher than the touchy 20 amp GFCI will tolerate, but I'd be concerned about any circuits that didn't have a load on them.

I suspect that ground leakage can be responsible for electrolysis issues, too.
 
The problem may be the multiple GFCI breakers in series (so to speak). The OP wouldn't want to remove them from his boat because he would want them when at other marinas.

As a test, manually trip all the GFCI breakers on the boat and then see if the shore pedestal breaker will hold. If it does, reset the boat's GFCI breakers one by one and see if the shore pedestal breaker trips.

The easy, no brainer solution is to remove the shore pedestal GFCI breaker and replace it with a standard breaker but you would need the marina's permission to do this.
 
rawidman, I added this as troubleshooting information. I'm still operating under the assumption that I have a ground fault problem. However, I am not dismissiong the possibility that the marina has a problem also. I have an electrician checking out the boat now.
 
Believe it or not, most boats that have a reverse polarity indicator light will trip a GFCI plug or breaker. There is more than 5 milliamps to the neutral across this indicator light, and therefore will cause it to trip.
There is nothing wrong with your boat or the shore power wiring.
Marinas are required to have GFCI outlets on 20 amp receptacles.
Answer would be to have marina install a 30 amp twist lock receptacle in place of the GFCI, even if its protected with 20 amp circuit. This will meet code.
 
quote:
Originally posted by GSENTAnswer would be to have marina install a 30 amp twist lock receptacle in place of the GFCI, even if its protected with 20 amp circuit. This will meet code.

Click to expand...

That is the current setup based on what the OP stated. 30 amp twist lock receptacle being protected by a 20 amp GFCI breaker. His marina may be limiting maximum power to 20 amps. 20 amps is plenty to power up most items but not two very power hungry items.
 
I would agree with GSent, there is probably nothing wrong with the boat or the shore power.
From new, my Silverton would trip systems with a GFI in the shore power at the shore power location.
When I am on the hard, the only way I can get power to the boat is to use a cord with the ground not in tact.
When I initially had this problem over 10 years ago, I found that all or most Silverton boats seem to trip the shore power GFI when plugged in.
edThis spring, when my shore power dock outlet was out due to Sandy, I tried to plug into the house outlet that has a GFI at the panel. It would always trip.
When I fixed the 30 amp outlet at the dock, the power worked well on the boat. There is no GFI on my dock outlet.
 
quote:
Originally posted by Pa Mikee

quote:
Originally posted by GSENTAnswer would be to have marina install a 30 amp twist lock receptacle in place of the GFCI, even if its protected with 20 amp circuit. This will meet code.

Click to expand...

That is the current setup based on what the OP stated. 30 amp twist lock receptacle being protected by a 20 amp GFCI breaker. His marina may be limiting maximum power to 20 amps. 20 amps is plenty to power up most items but not two very power hungry items.

Click to expand...
+1 Bingo I think we have a winner.
Bill
 
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