older boats circuits and new breakers on shore

[davil]

Have been having frequent breakers tripping incidents and no significant changes made on the boat as far as loads or new items added.
The only change is the replacement with new breakers on shore by the marina to comply with GFCI protection.
Asked a marine electrician to look at my set up as is a new (old) boat and has the usual (unusual)wires in the panel.
After a major clean up the breakers kept tripping,finally my electrician called the office for standards and if I understand it has to do with the new breakers/panels been installed with GFCI protection and that affects ONLY older boats where AC and DC at certain sections share a common grounding???
My suggestion to install a new dedicated AC panel isolated from any DC load did not work as the electrician indicated the areas of contact can be "anywhere"in the boat?
his solution at this time was to separate the supply to the batteries charger from the original panel to a dedicated electric extension running from the dock box to the charger.
It works but cannot see this as a permanent solution.
Anybody knows about this???
Newer boats do not seem to display this problem.

[smac999]

a properly wired boat will not trip a dock GFI.

a properly wired boat (in north america anyways...) has ac ground connected to DC neg. that is not your issue. and you should reconnect this bond.

your issue is likely a connection between ac ground and ac neutral.

do you have an inverter / charger on board? they are the main cause if not wired correctly.

I have fixed brand new million dollar boats that trip GFCI dock breakers. old or new does not matter. correct vrs wrong is what matters.

if removing the battery charger from the AC panel solves the tripping. likely the charger is fautly. though likely the charger is being run from a 15a GFCI on the dock?...

[EngNate]

Definitely a connection between AC neutral and ground causes GFI tripping because there will be current in the ground wire (also a corrosion issue). Improper wiring of an inverter's AC output is often the cause. Another is a 240/120 volt domestic appliance such as a range or clothes dryer - these often come with a 3-wire cord and have the neutral and ground jumpered together. These must be on a 4-wire cord and circuit. I have sometimes found the ground and neutral busses intentionally jumpered together, as may be found in panels in a building. If not one of these causes then there is a ground fault in wiring or (a) device(s). With an ohmmeter or continuity tester you can check for a ground to neutral connection at your shore inlet: Test between the bent prong and the narrower of the other two - there should not be continuity.

If a generator is installed there will be a ground-neutral connection at the generator and the neutral wire goes through the ship-shore switch so the connection is in the boat's circuit only when the gen is supplying power. This is the only place for a G-N connection on board, a power source (including an inverter). Further particulars on inverter wiring would make this post quite a bit longer...

[davil]

Originally Posted by smac999

a properly wired boat will not trip a dock GFI.

a properly wired boat (in north america anyways...) has ac ground connected to DC neg. that is not your issue. and you should reconnect this bond.

will check

your issue is likely a connection between ac ground and ac neutral.

do you have an inverter / charger on board? they are the main cause if not wired correctly.

no

I have fixed brand new million dollar boats that trip GFCI dock breakers. old or new does not matter. correct vrs wrong is what matters.

if removing the battery charger from the AC panel solves the tripping. likely the charger is fautly. though likely the charger is being run from a 15a GFCI on the dock?...

============================================
thank you and EngNate
these past 6 months have been very frustrating outfitting a boat and having to hire help,in the past always done all work myself,
This explanation given did not make any sense and that prompted my posting.
This is a very simple wiring set up for a 30 ft Cape Dory,do not have any combined inverter charger,in fact the only "sophisticated" item was an electric water heater tank that was prompted removed to make room for more important stuff I needed room.
As the charger will be the only AC connected item and it works just fine out of an extension cable.
The only concern I had and was reassured,the bonding of both dc/ac ground and negative and that will double check.
thank you both for taking the time
david

[svfinlandia]

Originally Posted by smac999

a properly wired boat will not trip a dock GFI.
a properly wired boat (in north america anyways...) has ac ground connected to DC neg. that is not your issue. and you should reconnect this bond.

I have a toridal transformer on my boat which I have always assumed isolates me from shore power and also assumed that that is the reason that my boat trips onshore GFI breakers. The boat is a 1983 Nauticat built in Finland. Any other Nauticat owners have this problem?
Any thoughts on this?

Al, S/V Finlandia

[wrwakefield]

Davil,

You are likely dealing with an ELCI breaker at the dock power box. [Like a GFCI but for the whole boat.]

They started installing them in many commercial harbors here in Alaska a few years ago. Some local boats initially had problems [as do some visiting boats each season]— all similar to what you describe.

Assuming a properly wired boat, the most common culprits I hear about are improperly installed/wired/behaving inverters and/or chargers.

Here is a brief overview of how ELSI breakers work, and the relevant ABYC standard.

Waggoner Guide published a good article which includes troubleshooting overview if your boat is tripping an ELSI controlled shorepower source.

Best wishes getting it resolved.

Cheers! Bill

[wrwakefield]

Originally Posted by svfinlandia

I have a toridal transformer on my boat which I have always assumed isolates me from shore power and also assumed that that is the reason that my boat trips onshore GFI breakers. The boat is a 1983 Nauticat built in Finland. Any other Nauticat owners have this problem?
Any thoughts on this?

Al, S/V Finlandia

Hi Al,

Our Nauticat does not have an isolation transformer [EDIT: but it does have a galvanic isolator—*with capacitors...] You are correct, it should not cause a shore based [current leak detecting] breaker to trip.

We have many foreign vessels with isolation transformers visit each year, and I have yet to see one have issues in the harbors with ELSI breakers... [We get to know the crews on maybe 6 of these vessels/year, so not a large sample...]

We have never had an issue with the [ELCI] shore power breakers on our N43 [unless we draw more than 50amps...]

One difference [from most boats I'm familiar with] in the way we are wired is: our inverter is wired as another AC source [e.g., shorepower/ generator/ inverter] instead of a pass-through UPS style arrangement that most [recreational] boats seem to have. I do not know if this contributes to our lack of issues with ELCI breakers because I have not witnessed it wired this way on other vessels using ELCI protected shorepower for comparison...

If you haven't already, perhaps the troubleshooting steps from the [second] article I linked in my previous reply on this topic might provide additional insite.

In hopes some of this may be helpful...

Cheers! Bill

[EngNate]

If there is a ground/neutral connection on board the current that flows in the ground wire is dependent on the total load onboard. Likely the OP's battery charger is simply providing enough load to produce enough fault current, not that it is faulty itself. This would be proven by it working fine directly on an extension cord. Step 1 is a continuity test at the inlet between the neutral and ground connections, if so don't look in any other direction until that's been found and fixed.

[smac999]

Originally Posted by svfinlandia

I have a toridal transformer on my boat which I have always assumed isolates me from shore power and also assumed that that is the reason that my boat trips onshore GFI breakers. The boat is a 1983 Nauticat built in Finland. Any other Nauticat owners have this problem?
Any thoughts on this?

Al, S/V Finlandia

it should be impossible for that to trip. because the ground wire goes no where.

either the wiring is wrong (shore ground wire attached to something besides the coil sheild) or something in the transformer has failed.

it's possible to trip a reg breaker with a transformer. if you don't have a soft starting device of some sort. but this would happen at every dock

[smac999]

Originally Posted by wrwakefield

One difference [from most boats I'm familiar with] in the way we are wired is: our inverter is wired as another AC source [e.g., shorepower/ generator/ inverter] instead of a pass-through UPS style arrangement that most [recreational] boats seem to have. I do not know if this contributes to our lack of issues with ELCI breakers because I have not witnessed it wired this way on other vessels using ELCI protected shorepower for comparison...

Cheers! Bill

if your switch switches the inverter netreal wire, then that will prevent the issues others are having with inverters. their issues are not wiring there inverters correctly with a seperate neutreal bus. but having a shared neutreal bus with inverter loads and shore. with your swtich the neutreal bus is either one or the other. not shared.

[boatpoker]

Do you have a Xantrex charger ? Some models are known to have excessive leakage into the DC side and this could cause an imbalance between hot and neutral which could trip a GFCI.

[OS2Dude]

Originally Posted by smac999

a properly wired boat will not trip a dock GFI.

A properly wired boat (in north america anyways...) has AC ground connected to DC neg. that is not your issue. and you should reconnect this bond.

If you are new to electrical terms, the ground mentioned here is the GREEN SAFTEY GROUND. ABYC states this is to be connected to the Black DC Ground. (In modern/rewired boats DC Ground may be Yellow to avoid confusion with the AC Load <aka HOT> wire.) DO NOT connect the DC Ground to the White AC Neutral.

[CharlieJ]

Some good info here. I work on three of these problem boats per month and it is only going to get more predominant as more marinas upgrade to 30mA ELCIs.

The absolute first step is to test between N and G busses to ensure there is at least 25,000 ohms of resistance between them. There won't be. While monitoring the N > G resistance at the buss, remove each N wire from the buss until the resistance improves between the two busses to > 25,000 ohms. You will then have to correct that N > G bond in the piece of equipment identified. The usual suspects are: failed water heater element ceramic coating, mis-wiring (I had one last week where the N wire was landed on the G buss!), failing battery charger, failing insulation on air conditioning compressor units.

There are other methods for determining the leakage but, with a good DMM, this will work.

An excellent discussion about this issue can be found here: https://tinyurl.com/y7xjm6jo

[evm1024]

As CharlieJ suggests testing the resistance between Neutral and Grounding would be good. Safety suggests that you disconnect your shore power connector and be sure that the inverter cannot energize.

125 v / 25,000 ohms gives a current of 5 mA. So a resistance greater than 25k ensures that a GFCI would not trip.

Of course testing the N to G resistance would need to be done without a Neutral to Grounding connection (as is common with isolation transformers) and with inverters when in inverter mode.

Also, our marina retrofit the shore power pedestals with 5 mA GFCI breakers rather than 30 mA ELCI type breakers. There were 2 reasons - firstly the marina wanted to protect people. Secondly, the GFCI type were 3 or 4 times less expensive.

When first installed there were perhaps 6 boats that tripped the 5 mA breakers. Each and every boat had some fault or in 1 case an inverter/charger that was just leaky between N and G. It turned out that the inverter had some corrosion internally...

Lastly, One of the GFCI protected sockets on my boat started tripping. At first I reset it and it took a few minuted before it tripped again. As I was going to reset it again I realized that there was a reason for it tripping.

As it turned out there was an extension cord plugged into a down stream outlet that was on the same GFCI. The end of the extension cord was out a hatch and on deck where I had been working. It had started raining and got the extension cord outlets wet.

It does not take much but it was a real problem. With old wiring you will have leakage. Your task is to find it.

[davil]

Just thinking on how to solve my problem,considering the electrician felt was going to be a major time investment task.$$$$$$$$$$
I am replacing the original Marinco plug on the boat and replacing it with a Smart Plug design.
I do not trust this old thing and that might be part of the problem because of water penetration?
If I add a new ELCI Main 30A Double Pole + 2 Positions to bypass the AC part of my original AC/DC panel,and disconnect all wiring AC as well as the "green" to common ground on this the original panel.
Then proceed with connecting my only 2 AC needs, one to battery charger and the other the 110 v outlets in the cabin.properly wired fused and sending the green to common ground as per specs,each circuit out of individual sized breakers,that should be a clean install right?
do not have inverter/charger.my inverter is a single function drawing from dc on demand and do not have a water heater,the fridge is now working from either dc or ac and again that is not a problem as can run from dc constantly as long as the battery charger is on.
Just a thought,the only added expense will be the new distribution panel but cheaper than having an electrician working for hours.
Again all 110 volts from original install are removed/disconnected.