Tripping GFI for shore power

Evening Gents,

Ty PondTunes so far for your help, your suggestion of rebuilding the voltage regulator solved my first problem of the cd player shutting down to protect itself during the voltage spikes, so for that I thank you.

On to my still prevailing problem, whenever I plug in my extension cord from the plug at the dock to my shore power twist adaptor plug that plugs into the port side of the boat, I trip the GFI at the plug instantly. I have tried different cords, different adaptors, so the problem is definately with the boat itself. There is nothing connected in terms of AC at all, I dont have a hot water tank, fridge, stove or anything of that nature. I pulled the dash for kicks and inspected all wiring, and could not find anything odd.

The is not a problem of necessity, since I can simply run the extension cord into the boat to run any electronics that I like, but it is the principle of it that is annoying me. I do not enjoy not being able to fix something, and the problem is always in the back of my mind.

Any ideas on where to begin troubleshooting this now?

Re: Tripping GFI for shore power

did you have the GFI outlet checked by an electrician or a hand held tester? If so and it's good work your way back through the boat looking for things suggested earlier like damaged wiring that could be leaking current (even inside the boat)

Re: Tripping GFI for shore power

Where does the AC go when it enters the boat, there must be some kind of a distribution panel with a master breaker somewhere or is it a hack job done by a previous owner? Find the source and through a process of elimination find which leg or feed is causing the problem. Use extreme caution though as this is not 12v, if your not comfortable around the 110 then maybe you should get a qualified electrician.

Re: Tripping GFI for shore power

Make sure the grounds and neutrals are separated in your boat distribution panel. Many people will put them together in the panel "because that is the way it is done in my house". Grounds and neutrals can only be tied together in a main service panel. If they are tied together in your boat, the GFCI will trip every time and rightly so.

Re: Tripping GFI for shore power

I tried my boat on all the other plugs in the marina, and tripped them all. Also tried another boat on my GFI, and all was well.

Please excuse my ignorance, as I have never had a boat with a shore power hook up before, I am unaware of a "distribution panel" anywhere for the AC. There is a fuse panel of course at the helm for the DC accesories and the like, but am unaware of an AC panel??? The exterior plug is on the port side of the boat. The cuddy is panelled, so am unaware where the wiring goes from there. There are 2 outlets that I am aware of. I guess I will have to start ripping things apart to find the cause of this. This is not a hack job, is the original wiring for the boat. Im assuming since there is nothing actually hooked up to the AC, it must be a nicked wire somewhere leaking to ground?? Or of course the aforementioned "distribution panel", if I could only find the bugger !

You guys also mention to be careful around the 110, but if it is not plugged in to the shore power at all, there should not be any current there correct?

Re: Tripping GFI for shore power

"f a ground fault exists with some of the current flowing to ground and not returning on the neutral through the transformer, then the sum of the current flowing on the hot and neutral will not be zero and differential current will be detected. The GFCI's electronic circuitry then measures its magnitude. If it reaches a predetermined level (the GFCI trip threshold) for a given duration, a signal causes the trip coil to energize and the circuit to open. Differential current can be caused by grounded tools and appliances having low levels of harmless leakage current. UL typically requires that leakage levels on tools and appliances be less than 0.5mA (about one-tenth the level necessary to trip a GFCI). Also, a differential current can result from other causes such as sharing the neutral with another ungrounded conductor or from capacitive leakage between the ungrounded circuit conductor and ground."


They also do wear out besides the other possible problems and can trip with leaks as low as 6mA

Re: Tripping GFI for shore power

Chris...I went into my archives and found a Cadorette 1989 brochure, neither the Holiday 200 or 210 have shorepower listed even as an option, not until you hit the model 250 is it listed and it also included a breaker panel. I strongly doubt any manufacturer would install shorepower without a breaker panel installed somewhere obvious with easy access. I still suspect what you may have could have been installed by a previous owner and I would still say to be cautious when you plug it in trying to find the problem source.

Re: Tripping GFI for shore power

agreed if theres not a breaker panel you should really consider having a qualified marine electrician look at it if you're not comfortable with messing around with AC Power..

Just to give us an idea here where does the main power feed go when it comes through the hull? You should be able to at least follow the wiring to somewhere.... If it goes in and branches out to the outlets that bugs me as I agree if it was factory they would have put in a breaker box so that you could turn various outlets and things off.

A picture is worth a thousand words if you can snap a couple of various places where the ac wiring goes please do if you need a place to put the photographs let me know and i can host them for you.

Re: Tripping GFI for shore power

GFI's cause problems all the time, its a real pain but maybe I can shed some light on this subject.

Obviously trouble shooting stuff over the internet is a hard thing to do but this is my hunch, Ive ran into these GFI problems before as an Electrical Controls Technician.

I dont know a lot about ship to shore power as i have a small boat but im guessing this is what you ship to shore circuit is like

AC Power>>>>Battery Charger/Float Charger>>>>Batteries>>DC Accessories to boat.

Anytime there is large rectification of AC-DC you run into a potential GFI problem. There are fair sized capacitors in these charges and as they grow older they leak more current to ground. Even newer Inverters will do this. a few month ago I worked on a circuit that converted 120vac to 208 3 phase and it would blow a GFI every time. And it was less than 10 years old. I had 3 of the same brand inverters and they all did the same thing, blow GFI's. The only solution I knew of was to go to another manufacturers product.

Heres what ill suggest to you.

First remove the circuit that goes from Batteries to 12v Accesories.

SO your circuit will look like this.
AC Power>>>>Battery CHarger/Float Charger>>>>Batteries

If it blows which im pretty sure it will then you really only have a few options. First check connections if they look alright. Make sure the wires and cables have no rotted insulation. if everything pans out, you gotta go to a new charger, or just live with it.

If it doesnt blow. Then post up here and we will continue to help out.

on more thing ill point out before I leave here is to make sure that the previous owner of the boat or marine mechanic didnt cross the Neutral and the Ground wires anywhere. although this sounds dumb I have seen it way too many times even with professional mechanics who are in a hurry. If you swap the ground wire with the neutral wire your circuit will work just fine,... until you use a GFCI

Re: Tripping GFI for shore power

Boatin Bob said:

Chris...I went into my archives and found a Cadorette 1989 brochure, neither the Holiday 200 or 210 have shorepower listed even as an option

Click to expand...

That is very interesting indeed, ty Bob. I could have swore that the shore power plug was factory. Now I know that the boat is new to me, but I cannot for the life of me find a panel anywhere, unless it is hidden. Where the shore power enters the boat, there is panelling on the wall inside the cuddy, so it is hard to tell where it goes, although I do know the location of 2outlets like I mentioned. There is nothing connected to it, not even a charger like previously mentioned. It is really not that large a boat, and could live without shore power, but, probably like it would most of you, it bothers me.

I will investigate further and post my findings, as i live in Hamilton and the boat is up on the Trent Severn. Have a good weekend all.

Re: Tripping GFI for shore power

Chris...how far up the Trent are you and do you ever make it down to Couchiching? If you will be doing so some time this summer let me know as I keep mine at Ojibway Bay Marina on Couch and would be glad to give you a hand with it.

Re: Tripping GFI for shore power

My marina is on Sturgeon Lake, but often travel through Couch and Simcoe, Sparrow, etc... on short trips with the wife. Awfully nice of you, and may stop by, if only to have a beer. Always nice having friends along the system in case you ever get in trouble, although I have found that 99% of the boaters in that area are extemely friendly and always willing to help a fellow boater. Great area to be in. I would like to get this sorted out since I want to add a battery charger, and would be nice to use Shore Power. Did not go up this weekend, as the weather was suppose to be poor and had to work, but will let you know next weekend how I did.
Tks Chris

Re: Tripping GFI for shore power

This may sound rather mundane, but did you try a different shore power cord?

Re: Tripping GFI for shore power

Chris: I've been following your thread with interest. I've wired two boats so far for shore power and have quite of bit of experience with 120V house wiring. First to your problem: If this were my boat, I would first disconnect from shore power. Then pull each on-board receptacle out of its box and check the connections. Black goes to gold screw; white goes to silver screw; green goes to ground screw. If all are correct, wrap two layers of electrical tape arond the sides of the GFCI to cover the screws and reinstall into the boxes. See if that solves your problem. If not, trip each of the GFCIs so that the receptacles are dead. Test if that solves the problem. If it does, one of the GFCIs is shorted internally. That's not unusual if they are more than a few years old - marine environment and all that. Trigger each GFCI in turn until the breaker trips. Then you've found the bad one. Replace it. If all this does not solve your problem, then the short is in the wiring. The place to start is at the cable connector. With power disconnected, pull the connector and check the wiring to it. If it's OK, work downstream on each line. Once you find the problem line and fix it, you should put in a master circuit panel. The installation is pretty straight-forward, but if you're uncomfortable around AC wiring, hire a marine electrician to do it. Good luck and let us know what you find. Hy

Re: Tripping GFI for shore power

littlebookworm....it sounds to me like the GFI that Chris is tripping is actually out on the dock at his marina where plugs his power cord into, not actually a GFI on his boat like I think you believe? He shouldn't be taking the marins'a GFI apart.


Chris...if you do get to Couch and stop by....beer's always on ice!

Re: Tripping GFI for shore power

I did not want him to touch the dock's GFCI; I suggested he check the ones on his boat. If one of them is shorted internally, it will cause the dockside breaker or GFCI to pop. Under no circumstances should he mess with shore boxes. If I remember correctly, he also indicated that other boats had no trouble at the dock connection and that he had the same problem at a different dock connection. Therefore the problem lies in his boat, not on shore. Hope that clears it up. Hy

Re: Tripping GFI for shore power

littlebookworm said:

Chris: I've been following your thread with interest. I've wired two boats so far for shore power and have quite of bit of experience with 120V house wiring. First to your problem: If this were my boat, I would first disconnect from shore power. Then pull each on-board receptacle out of its box and check the connections. Black goes to gold screw; white goes to silver screw; green goes to ground screw. If all are correct, wrap two layers of electrical tape arond the sides of the GFCI to cover the screws and reinstall into the boxes. See if that solves your problem. If not, trip each of the GFCIs so that the receptacles are dead. Test if that solves the problem. If it does, one of the GFCIs is shorted internally. That's not unusual if they are more than a few years old - marine environment and all that. Trigger each GFCI in turn until the breaker trips. Then you've found the bad one. Replace it. If all this does not solve your problem, then the short is in the wiring. The place to start is at the cable connector. With power disconnected, pull the connector and check the wiring to it. If it's OK, work downstream on each line. Once you find the problem line and fix it, you should put in a master circuit panel. The installation is pretty straight-forward, but if you're uncomfortable around AC wiring, hire a marine electrician to do it. Good luck and let us know what you find. Hy

Click to expand...

ty so much for the help, I will definately try your suggestions. I dont have to disconnect from shore power though since it trips instantly anyways

Boatin Bob said:

littlebookworm....it sounds to me like the GFI that Chris is tripping is actually out on the dock at his marina where plugs his power cord into, not actually a GFI on his boat like I think you believe? He shouldn't be taking the marins'a GFI apart.

Chris...if you do get to Couch and stop by....beer's always on ice!

Click to expand...

It is the dock GFCI that is tripping, but will pull the boat plugs and check into his advice. I cant really recall though if the outlets on the boat have a GFCI, although I imagine that they would have to, being on the water and all. If I do tour that way will stop by your marina to say hi. Will probably go on a tour this long weekend, just not sure which direction we will head yet. Have not gone east yet so may try that out.

Silvertip, yes, first thing I tried was another chord, but to no avail.

Re: Tripping GFI for shore power

I had a chance to troubleshoot on the weekend, and this is what I came up with.

I found the breaker box, so I switched the 2 fuses off then attempted plugging in the shore power. Still tripped the GFI. This leads me to believe that the problem has to be from the breaker box to Shore Power outlet on the boat correct? The lead is only a couple feet, could not see any nicks, cuts, abrasions, etc... on the cord itself.

Both outlets on the boat did not have a GFI, so could not trip them to test that anyways. Took the plugs apart none the less, and could not find anything unusual as per the wiring. The only thing that I did find was a green ground lead unaccounted for in one of the boxes, that was just left hanging, taped it up, but still no go.

Re: Tripping GFI for shore power

Chris it sounds like you are making some head way with this now. The best way to troubleshoot most electrical problems is by isolating circuits. By process of elimination you will find which is causing the problem. From what I read to date including your post today you have a breaker box that has two breakers and you shut both off. Those two breakers control two receptacle outlets and you have checked the method that they were wired. You are still experiencing a GFI breaker trip when the boat is plugged in.
You need to look at the connections at both end of the wire from the outside connection plug to the connection on the breaker box. Wires can get skinned when routing through the openings in the breaker box. If the wire is short why not just replace it so as to eliminate it.

Re: Tripping GFI for shore power

I agree, that replacing the cable is probably the best idea. Just wanted to get a go ahead from you more experienced electrical guys before proceeding. Tks for the response.