Ground fault trips on shore power

I have a 2002 novatec sundeck trawler.
Have never had a problem with plugging into shore power.
Just had my home dock rebuilt and new wiring code requires a ground fault breaker (in house at breaker box)
Now when I plug in, ground fault blows immediately.
This is with the power selector (in the boat between gen and shore power) turned to off and all breakers in the boat turned off.

Temporarily replaced the new ground fault breaker with a regular one and back to normal.

Thoughts and help appreciated!
Thanks

Do you have a galvanic isolator on the boat? Is your shore power ground tied to your boat's bonding system?

Ted

O C Diver said:

Do you have a galvanic isolator on the boat? Is your shore power ground tied to your boat's bonding system?

Ted

Click to expand...

What does that have to do with it ?

boatpoker said:

What does that have to do with it ?

Click to expand...

If the selector switch is to off, main breakers are off, then the neutral and positive are supposed to be open. Only not open shore power wire is the ground. Seemed like a good place to start.

What's your suggestion?

Ted

gfci or elc breaker,please confirm.

The design of some reverse polarity indicators (on a boat) will trip a GFCI breaker. Are your reverse polarity lights still in the circuit with the switch turned off?

O C Diver said:

If the selector switch is to off, main breakers are off, then the neutral and positive are supposed to be open. Only not open shore power wire is the ground. Seemed like a good place to start.

What's your suggestion?

Ted

Click to expand...

The ground is not in the GFI circuit. The GFI measures between hot & neutral.
A GFI or any AC outlet will work without a ground (until there's a problem
Could be a Chinese GFI, lots of fakes out there and a couple of major recalls. You never get enough info on these types of posts to offer a definitive answer.

boatpoker said:

The ground is not in the GFI circuit. The GFI measures between hot & neutral.
A GFI or any AC outlet will work without a ground (until there's a problem
Could be a Chinese GFI, lots of fakes out there and a couple of major recalls. You never get enough info on these types of posts to offer a definitive answer.

Click to expand...

I understand that. Some times you see ground and neutral tied together.

Ted

O C Diver said:

I understand that. Some times you see ground and neutral tied together.

Ted

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That is suicide and the cause of ESD (Electric Shock Drowning) with the exception of automatic switching within generators or inverters

boatpoker said:

That is suicide and the cause of ESD (Electric Shock Drowning) with the exception of automatic switching within generators or inverters

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Look BP, I'm not saying it's ok to do, I'm saying these are things you can look for that might explain it on the boat end. I'm not sure the level of experience that the OP has with regard to electrical wiring on a boat or on land. Not sure if he changed the breaker from GFI to non GFI. Not sure if he has done any wiring on the boat. I'm only asking questions to see what's there, determine the OP's level of boat wiring ability, and see if there is an easy obvious problem.

Ted

The reason I asked you to identify is that a Gfci will trip at 5ma, whereas an Elci will trip at 30ma.The Gfci is not a good choice to protect the whole boat,it is designed as a single device protection, whereas the elci is designed to protect the whole boat.Also, check to see if the Elci (if used) was installed correctly as to manuf. spec's. The hot leg and the neutral should be twisted together to cancel the emf, and the ground should not be run thru the sensing unit.These will give you false trips. Good place to start, before looking for problems as suggested in previous posts.

Panacea123 said:

I have a 2002 novatec sundeck trawler.
Have never had a problem with plugging into shore power.
Just had my home dock rebuilt and new wiring code requires a ground fault breaker (in house at breaker box)
Now when I plug in, ground fault blows immediately.
This is with the power selector (in the boat between gen and shore power) turned to off and all breakers in the boat turned off.

Temporarily replaced the new ground fault breaker with a regular one and back to normal.

Thoughts and help appreciated!
Thanks

Click to expand...

Before you replaced the breaker to a non GFI, did you disconnect the shore power cord from the power inlet on the boat to verify that the problem wasn't in either the dock power outlet or the shore power cord?

Ted

Perhaps this will help http://www.pcmarinesurveys.com/Marina%20Electrical%20Safety.pdf

GFCIs and ELCIs have only been used around boats relatively recently. Lots of older boats are configured with polarity lights, galvanic isolators, inverters or generators that will trip a GFCI. Many have the neutral and ground bonded at the panel, or elsewhere. Some boats have more than one of these issues.

If I could wave a magic wand to re-wire and re-equip the thousands of boats so configured, I would. But this is the way it was done for years, and it'll take quite a few more before every boat on the water is totally up to today's code. And by then, current codes and recommendations will be obsolete. And a new crop of experts will be telling us we're all floating around in killing machines.

Panacea123 said:

This is with the power selector (in the boat between gen and shore power) turned to off and all breakers in the boat turned off.

Click to expand...

I don't understand what you mean by this in the context of your original post?

Do you mean that even with the boat's power selector turned off, the GFI breaker still trips? If so that's probably a good clue for locating the problem.

This could be a nuisance problem light pilot lights on a galvanic isolator. Or it could be an indication of an un-safe, or potentially un-safe wiring in your boat. Either way, I think it's worth getting to the bottom of it. Wiring wears and chafes over time, and can produce an un-safe condition. Practices have evolved over time to create safer boat wiring and you might just have a boat built with old practices. And boat's get worked on and modified over time, often by people who don't fully understand grounding, neutrals, isolation and how they relate. You tripping breaker could be any of these things, and probably more. But it's an indication that you MIGHT have a serious issue, so worth investigating rather than just leaving the non-GFI breaker installed.

BTW, this type of circuit protection is slowly but surely making it's way into shore power, so it's just a matter of time until we all encounter it. Plugging into a dock when you are cruising and finding you have no power is a real pain. Given the opportunity to address this at my own dock, on my own time table, I'd be all over the opportunity and wanting to fix it so I know I can then plug into any dock without surprises.

Can you buy an ELCI breaker that would fit say in a GE distribution panel box?
I would like to get a 30 amp one some day.

Exceed 5 milliamp current leakage out the hot wire and a GFCI will blow open.
I had to redesign my revere polarity indicators to use neon bulbs and also remove my buzzer or it would blow a GFCI breaker open.

On my boat, the reverse polarity indicator is I think after the dual pole breakers, so if they are off they don't matter.

Once in a while I test my entire boat, plugging shore cable into an GFCI extension cord, and it works fine, so I have no current leaks. I have all outlets on GFCI and rarely they nuisance open, likely due to humidity.

I use Hubbell brand GFCI and Leviton, and square-d QO and these also do not buzz if you use an MSW inverter. Other types will buzz the GFCI on MSW inverters.

first place to look is the shore power cord. test the ends and boat socket for continuity between contacts.

sdowney717 said:

Can you buy an ELCI breaker that would fit say in a GE distribution panel box?
I would like to get a 30 amp one some day.

Exceed 5 milliamp current leakage out the hot wire and a GFCI will blow open.
I had to redesign my revere polarity indicators to use neon bulbs and also remove my buzzer or it would blow a GFCI breaker open.

On my boat, the reverse polarity indicator is I think after the dual pole breakers, so if they are off they don't matter.

Once in a while I test my entire boat, plugging shore cable into an GFCI extension cord, and it works fine, so I have no current leaks. I have all outlets on GFCI and rarely they nuisance open, likely due to humidity.

I use Hubbell brand GFCI and Leviton, and square-d QO and these also do not buzz if you use an MSW inverter. Other types will buzz the GFCI on MSW inverters.

Click to expand...

Elci breakers are designed specifically for the marine business.They can be installed in a shore power pedestal.If you are referring to a land based sub-panel,then it would have to be a gfci breaker.The code (land) now calls for these afci kind of breakers to be installed,instead of standard.They do play nice-nice with gfci outlets.

What is the difference between and AFCI and Ground Fault Circuit Interrupter (GFCI)?
There is a major difference between the functioning of an AFCI as compared to a GFCI (Ground Fault Circuit Interrupter). The function of the GFCI is to protect people from the deadly effects of electric shock that could occur if parts of an electrical appliance or tool become energized due to a ground fault. The function of the AFCI is to protect the branch circuit wiring from dangerous arcing faults that could initiate an electrical fire.
AFCI and GFCI technologies can co-exist with each other and are a great complement for the most complete protection that can be provided on a circuit.

great video from abyc on elci installation.

O C Diver said:

I understand that. Some times you see ground and neutral tied together.

Ted

Click to expand...

That should never be. The ground and neutral should only be connected together at the source. In the case of shorepower, that would be at the marina's or in this case the home's entrance panel. The point where the power company's service ends and the business or homeowners equipment is connected to it.

If the boat has an inverter or generator, this is the source (only when connected and supplying power) and in this case, the ground and neutral are connected together here but only when this is the source of the boat's power.

O C Diver said:

Do you have a galvanic isolator on the boat?

Click to expand...

A galvanic isolator only connects in series with the ground wire and should not affect a GFCI breaker's operation.


A GFCI breaker compares the current flowing in the hot and neutral conductors and if they are not the same, it shuts off the circuit. If the current is not the same, it must be flowing to ground.


As I posted above, some, possibly most or all reverse polarity indicator systems, by their design are a ground fault (the green or "OK" lamp is connected from hot to ground). Mine is.

Panacea123 said:

I have a 2002 novatec sundeck trawler.
Have never had a problem with plugging into shore power.
Just had my home dock rebuilt and new wiring code requires a ground fault breaker (in house at breaker box)
Now when I plug in, ground fault blows immediately.
This is with the power selector (in the boat between gen and shore power) turned to off and all breakers in the boat turned off.

Temporarily replaced the new ground fault breaker with a regular one and back to normal.

Thoughts and help appreciated!
Thanks

Click to expand...

If you haven't encountered this problem before, you would have soon if you stay at marinas. Now's the time to get an electrician and get your boat wiring compliant. Rather than fight the problem accept it as a warning.

WesK said:

That should never be. The ground and neutral should only be connected together at the source. In the case of shorepower, that would be at the marina's or in this case the home's entrance panel. The point where the power company's service ends and the business or homeowners equipment is connected to it.

If the boat has an inverter or generator, this is the source (only when connected and supplying power) and in this case, the ground and neutral are connected together here but only when this is the source of the boat's power.

Click to expand...

WesK said:

A galvanic isolator only connects in series with the ground wire and should not affect a GFCI breaker's operation.


A GFCI breaker compares the current flowing in the hot and neutral conductors and if they are not the same, it shuts off the circuit. If the current is not the same, it must be flowing to ground.


As I posted above, some, possibly most or all reverse polarity indicator systems, by their design are a ground fault (the green or "OK" lamp is connected from hot to ground). Mine is.

Click to expand...

Wesk, I addressed this in post #7. Not condoning this, looking for alterations to the original wiring that could cause the problem.

Ted

O C Diver said:

Wesk, I addressed this in post #7. Not condoning this, looking for alterations to the original wiring that could cause the problem.

Ted

Click to expand...

Sometimes things have to get posted several times before anyone pays attention. For example, my comment on the reverse polarity indicating lights.

It's pretty easy to check to see if the ground and neutral are connected together on the boat with nothing more than an ohm meter or continuity tester.

Anyone who can't figure how to do this should get on the Internet and start looking for a good marine electrician.

Thanks for all the info
Have not had a chance to trouble shoot yet
But to clear up a few things.
The GFI is in the house at the main panel, it was just installed by the same company that wired the house, very well known co in this area.
I do have a reverse polarity light, and galvanic isolater
New magnasine inverter with neutral switching installed by a pro.

Yes it trips with gen/shore power selector turned to off and main double pole breaker turned off on boat panel, (trips as soon as it is plugged in). That's the weird part as you would think with it off no current would flow?

I suspect my problem lies with the selector switch as it does not appear to change the neutral wire (very hard to see where it is located)
Will dive into it more when I have time.

For now just replaced the breaker in the house with a non GFI unit. (It's been this way for 14 yrs with no problems)
Have a pro scheduled to come out in a week or 2

Panacea123 said:

Yes it trips with gen/shore power selector turned to off and main double pole breaker turned off on boat panel, (trips as soon as it is plugged in). That's the weird part as you would think with it off no current would flow?

I suspect my problem lies with the selector switch as it does not appear to change the neutral wire (very hard to see where it is located)
Will dive into it more when I have time.

Click to expand...

While I'm not the wire code expert in this thread , the neutral needs to be switched as it may now be tied to the generator neutral and possible the boat bonding system.

Ted

About reverse polarity indicators, they need to be 25,000 ohms minimum
I had to change mine and leave off the buzzer.
Wiring a reverse-polarity alarm - Ocean Navigator - January/February 2003
You can not just stick a pilot light in there, a neon light will work.

Answer 1: The proper way to wire a reverse-polarity alarm is as describedbetween the neutral and the grounding wire. The American Boat and Yacht Council (ABYC) standards specify that such a device should have a minimum resistance of 25,000 ohms. The reason for this is that if we apply Ohm's Law, assuming a 120-volt circuit, we find that, if the polarity is reversed, activating the device, the current flow will be 120/25,000 = 4.8 milliamps, which is just below the tripping threshold of U.S. Ground Fault Circuit Interrupters (GFCIs); they trip at 5 milliamps. This way the alarm will alert the operator without tripping the circuit. With such a high resistance in the circuit provided by the 25K-ohm resistor, there is no need to worry about leaks to ground, galvanic corrosion, etc.

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BandB said:

If you haven't encountered this problem before, you would have soon if you stay at marinas. Now's the time to get an electrician and get your boat wiring compliant. Rather than fight the problem accept it as a warning.

Click to expand...

+1 on this.
When we stayed at Fort Pierce City Marina, they had you come to the fuel dock for "testing" before they would allow you to use the new floating docks with the new electrical pedestals referred to in this thread. They had you plug in with all circuits turned off, then flip each circuit on, one by one. We were thankful that we passed.

sum escape said:

+1 on this.
When we stayed at Fort Pierce City Marina, they had you come to the fuel dock for "testing" before they would allow you to use the new floating docks with the new electrical pedestals referred to in this thread. They had you plug in with all circuits turned off, then flip each circuit on, one by one. We were thankful that we passed.

Click to expand...

We stayed at a marina which the dockmaster proudly told me had recently installed a very expensive electrical management system which could pinpoint any problem, down to which outlet on which pedestal.

When I expressed concern that my boat was built before GFCIs were common, he couldn't wait to try out his new toy. He reported back that we were "100%" OK according to his system.

Actually, there was one problem outlet that did trip a GFCI at another marina, but I wasn't using it at the time.