Popping the Marinas GFI

[lovinlifebda]

Hello electical giants,

When I bought my boat it was in a marina that did not use GFIs and never popped the breaker without good reason. Lived there a little over 3 years and then went cruising. First marina we use has GFIs and as soon as I turn the breaker on for the air con or the hot water tank or the inverter/charger then the breaker pops. The main switch for the panel does not cause it to pop but any device does. The marina had bypassed the GFI on a number of outlets because of them tripping, if I used one of those then no problem. We are now in another marina and same problem. The boat was built in 1995 and I am owner number 5. There is obviously a current leak somewhere, but I have no idea how to look for it. I have a bad feeling this could be the needle in a haystack. Does anyone have some suggestions on at at least where to start. Thanks Jim

[bobofthenorth]

You're on the right track trying to isolate the problem according to the breakers. You may have more than one discrete problem. In other words there is likely a different circumstance causing the GFI to trip on each separate circuit. The inverter should trip the GFI. When the inverter is the source it is required to bond the ground and neutral lines. When the inverter senses input voltage it should lift that bond (and it likely does) but it won't likely lift the bond quickly enough to prevent the GFI from tripping. If your inverter is wired in pass through then that will be difficult to deal with - there is a workaround but I'm not going to post it. If your inverter is on a separate breaker then you should simply be able to leave it shut off and run the boat on pedestal power.

The water heater is also pretty easy to imagine a ground fault. If the element is starting to fail it will leak current to ground through the water in the tank. If the AC is alone on that circuit I'm not sure what to suggest. If there is anything else on the circuit with the AC then the first thing I'd do is disconnect whatever else is on the circuit and test each item independently.

[capngeo]

A lot of boats will run their AC current through an onboard GFI.... The shore-side GFI doesn't like having another in the circuit and is tripping as a result. The solution is to do away with one or the other. Try to plug into a 30 or 50 amp outlet and use an adapter.

[lovinlifebda]

Bob, Thanks for that reply. I have an Outback charger/inverter that was on the boat when purchased and it is apparently in complete control of the AC outlets on the boat and of course the charging of the battery bank. So without being able to turn it on, Shore power does me no good. Thanks again for the explanation, at least now I understand why the inverter trips the breaker. Maybe I can convince this marina to bypass the GFI when I explain it to them.

[botanybay]

Originally Posted by capngeo

A lot of boats will run their AC current through an onboard GFI.... The shore-side GFI doesn't like having another in the circuit and is tripping as a result. The solution is to do away with one or the other. Try to plug into a 30 or 50 amp outlet and use an adapter.

I am not sure I can understand why two GFCIs in a row would be a problem. The devices themselves do not leak current except when under test.

I have a whole boat GFCI (30ma trip) prior to the inverter and then one after the inverter (30ma trip) as well as smaller units for the bathroom (5ma trip). Have not seen any problems from them interacting.

[botanybay]

Originally Posted by lovinlifebda

Hello electical giants,

When I bought my boat it was in a marina that did not use GFIs and never popped the breaker without good reason. Lived there a little over 3 years and then went cruising. First marina we use has GFIs and as soon as I turn the breaker on for the air con or the hot water tank or the inverter/charger then the breaker pops. The main switch for the panel does not cause it to pop but any device does. The marina had bypassed the GFI on a number of outlets because of them tripping, if I used one of those then no problem. We are now in another marina and same problem. The boat was built in 1995 and I am owner number 5. There is obviously a current leak somewhere, but I have no idea how to look for it. I have a bad feeling this could be the needle in a haystack. Does anyone have some suggestions on at at least where to start. Thanks Jim

I am owner number 4 for my boat and I empathize! I was having serious problems with shore power and intermittent whole boat GFCIs popping, I traced every wire on the neutral bus and found one connection which was going from the neutral bus to the ground bus. Depending on which equipment was being used it would trip the GFCI intermittently.

[BandB]

The solution is not the marina bypassing it. It's there for a reason, a good one. You really need to figure out what is causing it from your boat. If you can't find it, maybe time to bring in a marine electrician with the equipment necessary to locate the leaks.

[bobofthenorth]

Originally Posted by BandB

The solution is not the marina bypassing it. It's there for a reason, a good one. You really need to figure out what is causing it from your boat. If you can't find it, maybe time to bring in a marine electrician with the equipment necessary to locate the leaks.

Sorry but its nowhere near that simple. I agree that bypassing a safety feature that is implemented for good reason is a bad idea. I take quarrel with whether GFI's make sense in a marina or RV park environment. I'm not going to get into this debate here but from the OP's standpoint, hiring a "marine electrician" as you have suggested, will likely accomplish exactly nothing other than enriching the clown posing as an expert.

[BandB]

Originally Posted by bobofthenorth

Sorry but its nowhere near that simple. I agree that bypassing a safety feature that is implemented for good reason is a bad idea. I take quarrel with whether GFI's make sense in a marina or RV park environment. I'm not going to get into this debate here but from the OP's standpoint, hiring a "marine electrician" as you have suggested, will likely accomplish exactly nothing other than enriching the clown posing as an expert.

I didn't suggest hiring a clown posing as an expert. I was suggesting one experienced with working with this issue and with good references for doing so. They may not be prevalent in some areas but in South Florida there are certainly many as they've encountered similar issues at every marina. It is a specialized field that just anyone isn't proficient in, but there are some who are highly competent in this field. I know one marina that even made one available to all it's tenants on their dollar when they converted their systems. He assisted all boats encountering problems for several weekends.

Now as to whether GFI's make sense or not isn't the issue here. The fact is they are there, in many places they are required by law or ordinance, and we have to learn to live and coexist with them.

[bobofthenorth]

Originally Posted by BandB

I know one marina that even made one available to all it's tenants on their dollar when they converted their systems. He assisted all boats encountering problems for several weekends.

I can only imagine how much he "assisted". No doubt at considerable cost to those affected. I find it highly unlikely that the alterations to the boats in that marina were paid for by the marina.

The point is that there very well may be nothing substantially wrong with the OP's boat. This is a well known problem with GFIs when they are used to power complex systems. In that circumstance a marine electrician in the employ of the marina is unlikely to identify the root cause of the problem. And it is guaranteed that whatever solution he proposes will come at some expense to the boat owner.

There is no doubt that some boats have GFI problems that are in fact dangerous and should be corrected. However it is equally true that the simple fact that a given boat trips a shoreside GFI does not automatically mean that boat is in fact dangerous.

[BandB]

Originally Posted by bobofthenorth

I can only imagine how much he "assisted". No doubt at considerable cost to those affected. I find it highly unlikely that the alterations to the boats in that marina were paid for by the marina.

The point is that there very well may be nothing substantially wrong with the OP's boat. This is a well known problem with GFIs when they are used to power complex systems. In that circumstance a marine electrician in the employ of the marina is unlikely to identify the root cause of the problem. And it is guaranteed that whatever solution he proposes will come at some expense to the boat owner.

There is no doubt that some boats have GFI problems that are in fact dangerous and should be corrected. However it is equally true that the simple fact that a given boat trips a shoreside GFI does not automatically mean that boat is in fact dangerous.

He did troubleshoot any boats where asked and it was paid for by the marina. Substantially wrong? You're right there may be nothing dangerous wrong, but still it is something causing a lot of annoyance to the owner. And you're right it doesn't mean it's dangerous if it trips the GPI, just means it has a problem that will annoy the boat owner. Most of the fixes I've seen were minor but some were expensive. I'm just saying there are people trained in this area who also have the equipment to help them troubleshoot the problem. Often the problem was as simple as single item connected to the circuit.

Again, I am not saying there are qualified people everywhere. I just know there are where we live. The OP I believe is in the Caribbean so that could lessen the probability of help.

[St. Elsewhere]

Is this thread talking about GFI's on:

1. 15 amp 120 volt connections,
2. 30 amp 120 volt connections,
3. 50 amp 120/240 volt connections

or all of the above?


I would expect item 1 to be common, but I have not been aware of encountering 2 & 3 at any marina. If they are used on larger circuits I would expect lots of trips.

[bobofthenorth]

I'm not sure which the OP is referring to but I've seen 15 & 30 amp GFIs in marinas. I understand that in some jurisdictions the electrical code calls for them on 50 amp services as well but I have never seen that.

R.J.(Bob) Evans
www.travellingwithgeorge.blogspot.com

[capngeo]

Originally Posted by botanybay

I am not sure I can understand why two GFCIs in a row would be a problem. The devices themselves do not leak current except when under test.

I have a whole boat GFCI (30ma trip) prior to the inverter and then one after the inverter (30ma trip) as well as smaller units for the bathroom (5ma trip). Have not seen any problems from them interacting.

Fairly simple actually... first you need to understand a GFI and how it works; A GFI measures the power coming from the hot side, going to the neutral, when the values become unequal, the GFI assumes there is a fault and current is going to ground (possibly through a human), which trips the GFI and shuts down power.

Because all neutrals are bonded together in a 120VAC system, a TWO GFI circuit will you suddenly have TWO paths to neutral on the same circuit.. this confuses the values and one or both GFIs will trip.

Read up on NEC, Underwriter's and ABYC..... NONE of the codes allow more than one GFI on a circuit for the above reason. That said, you CAN have one GFI protect multiple outlets by connecting them THROUGH the GFI. The latter is how many smaller boats are wired. For instance, say the OP boat has 3 outlets wired after the GFI on ONE breaker: all is good. Now put a GFIC on the pedestal and plug into it... you now have two: bad.

Most small marine electric systems are designed to be plugged into either a single 30A 120V, two 30A 120V, or a single 50A 220V... NOT into a typical household 15 or 20 amp receptacle. Those (the 15-20A receptacles) are included in a pedestal for tools run direct to the pedestal independent of a marine (boat) system. With that in mind, and the possible shock hazard of nearby water (within 4' by code), a GFI is installed in the pedestal..... IT WAS NEVER INTENDED TO HAVE A BOAT PLUGGED INTO IT!

[capngeo]

Originally Posted by bobofthenorth

I'm not sure which the OP is referring to but I've seen 15 & 30 amp GFIs in marinas. I understand that in some jurisdictions the electrical code calls for them on 50 amp services as well but I have never seen that.

R.J.(Bob) Evans
www.travellingwithgeorge.blogspot.com

I've been in, around, over, and under marinas and boatyards for 40 years; in all that time, I've NEVER seen a GFIC in excess of 20A