GFCI Issues at Power Pedatals + AFDI

[spartonboat1]

Note: Typo in the Title: AFDI s.b. AFGI; Pedatals = "Pedestals"; can't edit the titles...
This is on a 1972 43' DCFB, which I have owned since 1997. These are 120v Single Phase circuits on these vintage of boat. All circuits have ground wires, i.e. the outlets are triplex with a ground.

UPDATE to Arc-Flash Concerns:
NFPA 70E states any circuit 240 volt or less and supplied by a 125 kva or less transformer is exempt.
The premise is there is not enough current capability to maintain an arc flash.
Therefore 120 volt receptacles don't qualify to be rated, aka is rated HRC 0.
If any on here know otherwise, please indicate on this thread.
I will pull all the AFGI from here later... Thx...
Note of the You-Tube videos spells out the volts or kva

Apparently the vast majority of marinas where I have moored for the past 25+ years, did not have GFCI Pedestals. Now for the 2nd time in 10 years, I am tripping the breaker at the Dock Pedestal and have learned that it is GFCI, both 30amp, 50amp. I am tripping the 50amp, but not the 30amp (AC dedicated).

I am in the process of installing an "isolation" transformer on my 50amp input. Since the Pedestal only "sees" the Transformer, this should cease the 50amp Dock GFCI from tripping. The boat has several GFCI protected outlets, and I have never had an issue with them. I am told some boat owners have spent over $1,000 chasing Dock GFCI issues, to no avail!

FWIW, the transformer is an Acme 120v, 7.5Kva (50amp) shielded unit; weighs 105#'s. Ward Electric in FL installs a lot of these on boats.

What is occurring, is that many if not all marinas are now upgrading their electrical to GFCI at their pedestals. It is reported that marina managers are experiencing a large number of tripping of their GFCI equipped pedestals; this is true of the marina that has been servicing my boat. In addition, the Feds have lowered the trip points from 100ma to 30ma, i.e. much more sensitive. I have had several conversations recently with a marine engineer, and he says calls about tripping GFCI at the dock, are up 1,000% over the past year.

Also, in researching this issue, I have discovered that Arc-Flash can be a huge issue, and can occur on 120v circuits at 15 and 20amps. To prevent Arc-Flash, AFGI breakers are available. Since AFGI and GFCI sort of interfere with each other, there are combo AFGI/GFCI breakers, which eliminates the need for GFCI at the "wall".

Finally, since owning the boat, I had a 20amp Charger/Inverter installed, including a "Transfer" switch. Note that when the Inverter is engaged, its internal circuits only support 20amps, so that is a limiting factor; I will stop there.

So my questions are:
1) Do you have an Isolation Transformer? If you have an older boat (80's?), probably not.
2) Are you running into issues tripping GFCI pedetals in the past or more currently. They are new at many marinas now.
3) Do you have any AFGI breakers on your boat panel(s)? Many homes do not have AFGI breakers, so you would think boats would be so equipped even less.

Actually, I am a lot concerned about Arc-Flash, per the many You-Tube videos on the subject. Have an Arc-Flash on a boat, and "Goodbye" boat! I have seen nothing about GFCI or AFGI in the BoatUS (now Geico) publication.

End of my techie talk. My transformer is inbound to Grainger's next week. They had four in stock at this size (120v single phase, 7.5 Kva, 50am), so must be demand for them. $1,800, cheap at the price, if works!

Thanks...

 

[Pascal]

I had never heard of arc flash breakers before. Are marine versions available?

As to marina GFCI, 99% of issues are caused by appliances not by the boat electrical systems. Some appliances, mostly older, bond N and G which causes the GFCIs to trip. When my marina was rebuilt I was concerned about having issues with the new GFCI system. I don’t have a isolation transformer but I had redone the entire electrical incl wiring and panel 4 years ago. All new appliances as well incl cooktop, fridge etc. No issue when I connected for the first time

A number of folks in the marina struggled with this though and to make things worst all the GFCIs are installed in large locked electrical boxes, requiring marina staff to come unlock and reset. The solution is pretty simple: disconnect appliances one by one until the culprit is found. What many don’t realize is that turning off each breaker doesn’t work since the breakers only shut down the hot, not the neutral. You have to physically unplug the appliances.

The other common causes are non marine inverters which permanently bond N to G

While iso transformer obviously have benefits, it’s a lot cheaper and easier to address the issue at the source, the appliances.

 

[cww]

Short solution, buy an isolation transformer for each shore power leg. I thought these boats all came with them I'm surprised yours doesn't already have them. Mine has 2 of them in the generator room. That's the easy solution. There is almost certainly no actual hazard on your boat, it's a bunch of whining that started when a diver got electrocuted at a marina (which later turned out to be the marina's wiring not the boat he was working on, but I digress).

The more difficult solution is it's almost certainly one or more of your appliances causing the ground "fault". It's not really a fault, older appliances were designed with what was then considered an acceptable amount of leakage to ground. It's not a big deal, except when you get to a marina with GFI breakers. The most likely culprits are anything with a heating element, so start with the stove, washer/dryer, dishwasher, refrigerator (people forget they have elements in them for auto-defrost), or water heater. Turn the breakers off for each one of those, then plug the boat in and turn them on one by one until you figure out which ones are causing it. Then buy new appliance(s) to replace the one(s) with the issue. If you go this route, do not buy a warehouse deal or closeout sale, or anything of that nature. Walk into a high-volume retailer like best buy or home depot and get them there. The new rules were put in place in 2015 and started taking effect in 2016, so they have to be pretty recent. Appliances built from 2016+ are no longer allowed to have any leakage to ground, so with new ones you'll be ok.

A second possibility to the above is that it's the inverter. Like older appliances, older inverters through the mid 2000's had non-zero leakage to ground that was then considered acceptable, but which will trigger a ground fault interrupt breaker. This one is different because the breaker is usually set up to cut power off from the inverter, not to the inverter. You will have to go disconnect the battery leads to it and see if that stops the breaker from tripping. Newer inverters do not leak anything to ground, so the solution is replace it.

There is almost certainly nothing wrong with your boat's wiring, is the good news. The bad news is none of these options are cheap. I have actually been toying with the idea of putting together a portable iso-trans with shore power plugs on it for this reason. I could probably sell it for $1k and it would save people a lot of money. This problem is only going to get worse with time, as more marinas go to GFI pedestals.

 

[cww]

I had never heard of arc flash breakers before. Are marine versions available?

As to marina GFCI, 99% of issues are caused by appliances not by the boat electrical systems. Some appliances, mostly older, bond N and G which causes the GFCIs to trip. When my marina was rebuilt I was concerned about having issues with the new GFCI system. I don’t have a isolation transformer but I had redone the entire electrical incl wiring and panel 4 years ago. All new appliances as well incl cooktop, fridge etc. No issue when I connected for the first time

A number of folks in the marina struggled with this though and to make things worst all the GFCIs are installed in large locked electrical boxes, requiring marina staff to come unlock and reset. The solution is pretty simple: disconnect appliances one by one until the culprit is found. What many don’t realize is that turning off each breaker doesn’t work since the breakers only shut down the hot, not the neutral. You have to physically unplug the appliances.

The other common causes are non marine inverters which permanently bond N to G

While iso transformer obviously have benefits, it’s a lot cheaper and easier to address the issue at the source, the appliances.

I was in the process of writing this and went to grab a coffee and bowl of cereal and by the time I finished and hit the post button you had said the same thing. Spot-on.

 

[Boatsb]

Inverters improperly installed or subpanels not wired correctly are the number one cause n of these issues. I get 2 or 3 calls a week for this problem.

I have installed many new ELCI breakers on older boats. When the new breaker does not trip on shore power you will not trip a differant docks breaker. It's makes sure your 100%.

The ELCI is the new standard for ABYC and other groups for safety. If your upgrading your boat and don't put one in your crazy. I use the blue sea versions and have them on order all the time to try to keep inventory. As I said above if it doesn't trip on the dock power everything on board is ok. If it does you need to address a problem that is usually from bad installations.


FYI.

I am a Victron distributor and installer. I am Garmin, Raymarine, Furano and Navico trained too. I do this kind of upgrade almost daily. I have removed at least a ton of old garbage inverters and bad batteries this year already. It's amazing what some people do to their boats in the name of cosr or labor savings.

 

[SKYCHENEY]

Generally, all Hatteras models 50'+ and 1978 and newer came with isolation transformers. The smaller and/or older boats did not.

 

[SeaEric]

I added an isolation transformer last Spring along with a major AC and DC panels re-do. It's a worthwhile upgrade IMHO. Thread here: https://www.samsmarine.com/forums/showthread.php?35304-55-Year-Old-Electric-Panel-Upgrade

 

[riverrandy]

Very Interesting read. I am curious though now. My 1975, 64' has 2 giant transformers in the engine room. Together they are the size of one of the generators. They are much newer maybe replaced in the 90's. Anyway I have always assumed they are Isolation transformers. But last July when I arrived at my current marina It had just undergone a full restoration with new electrical. AT first there were no issues but then every once in a while I would pop the main breaker on the pedestal. After a while the marina electrician replaced the breaker with what he called the 100. the 30 would not work for me..."I draw too much". I did not understand but I thought it had something to do with poor English. Now I am not so sure. My question is I guess are my transformers for isolation or do they serve another purpose and unrelated?

 

[cww]

Very Interesting read. I am curious though now. My 1975, 64' has 2 giant transformers in the engine room. Together they are the size of one of the generators. They are much newer maybe replaced in the 90's. Anyway I have always assumed they are Isolation transformers. But last July when I arrived at my current marina It had just undergone a full restoration with new electrical. AT first there were no issues but then every once in a while I would pop the main breaker on the pedestal. After a while the marina electrician replaced the breaker with what he called the 100. the 30 would not work for me..."I draw too much". I did not understand but I thought it had something to do with poor English. Now I am not so sure. My question is I guess are my transformers for isolation or do they serve another purpose and unrelated?

Changing the size of the breaker indicates your boat was drawing more power than that breaker could handle, not that you had a ground fault.

 

[Pascal]

Dockside breakers must be matched to the type of outlet which in turn matches the type of shore power cord you are using. A boat your size should have never been connected to 30amp service in the first place. Even a single 50 isn’t enough. What cords do you have? Likely two 50amp? Using a 100 amp breaker with 50 amp cords may not be a great solution

 

[riverrandy]

Changing the size of the breaker indicates your boat was drawing more power than that breaker could handle, not that you had a ground fault.

I was not clear. The original breaker was a 50 amp, but a 30 Miliamp GFCI. He swapped in an "older version" 50 amp 100 miliamp GFCI. Have not had issue since.

 

[riverrandy]

Dockside breakers must be matched to the type of outlet which in turn matches the type of shore power cord you are using. A boat your size should have never been connected to 30amp service in the first place. Even a single 50 isn’t enough. What cords do you have? Likely two 50amp? Using a 100 amp breaker with 50 amp cords may not be a great solution

Pascal, Aquamarine has a 50 Amp 250 volt inlet on all 4 corners. She also has a 50 Amp 120 on each corner. I can select what I have plugged in. I can run 75% of the load on a single 50 amp 250. I balance the rest on a 50 amp 120 volt input. I have many of my lights, and small loads on that leg. I can switch to which ever corner is closest to the pedestal. If I have access to 2- 50 amp 250 volt connections, I will plug both into 2 corners (say both of the aft connections (port and starboard) the transformers seem to equal everything out. What I don't know is if my transformers also create that isolation that is now so important, or do they only clean up power from less than ideal power sources.