GFCI trips

Bob 04 H260

Bob 04 H260

.
May 16, 2007
1,509
Boatless ! 26 Ottawa, Ontario
I have two 30 amp lines coming into the boat. We were hauled last week and I used an adapter (30A to 15A) to connect the boat to a new power pedestal in the yard so I could run a dehumidifier over the Florida summer storage. The boat trips the 15 A GFCI on the pedestal as soon as the extension cord is plugged into either of the 30 A power input sockets, even with the AC panels turned off.

I am wondering if it could be caused by the galvanic isolators ? I don't see why as a GFCI can be used without a ground wire from what I know.

The main breakers and the isolators are the only thing connected if the panel is off. I did not have the problem last year but they just installed these new power pedestals with the GFCIs.

The only other possibility I considered is the reverse polarity light on the panels must be connected to the line, not sure if they are connected with the panel breaker turned off.

I am now running on a 30 amp shore power cord going through a 50 A adapter.

I do not have an inverter on board, our battery charger is fed off a breaker on the main AC panel.

Any suggestions on a test procedure ? As simple as unplug the power and start to measure resistance between hot and ground ?

thanks, Bob
 
woodster

woodster

.
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
Bob 04 H260 said:
I have two 30 amp lines coming into the boat. We were hauled last week and I used an adapter (30A to 15A) to connect the boat to a new power pedestal in the yard so I could run a dehumidifier over the Florida summer storage. The boat trips the 15 A GFCI on the pedestal as soon as the extension cord is plugged into either of the 30 A power input sockets, even with the AC panels turned off.

I am wondering if it could be caused by the galvanic isolators ? I don't see why as a GFCI can be used without a ground wire from what I know.

The main breakers and the isolators are the only thing connected if the panel is off. I did not have the problem last year but they just installed these new power pedestals with the GFCIs.

The only other possibility I considered is the reverse polarity light on the panels must be connected to the line, not sure if they are connected with the panel breaker turned off.

I am now running on a 30 amp shore power cord going through a 50 A adapter.

I do not have an inverter on board, our battery charger is fed off a breaker on the main AC panel.

Any suggestions on a test procedure ? As simple as unplug the power and start to measure resistance between hot and ground ?

thanks, Bob
Click to expand
take your 30 amp shore power cord with an adaptor on the boat end and plug some device drill motor or what ever you have in to it and then plug the shore power cord in the the dock receptacle and run the drill motor if it trips more than likely your boat is fine and it is the dock power.... if it runs and does not trip go further down the line until you isolate the source....
 
kito

kito

.
Sep 13, 2012
2,011
1979 Hunter Cherubini 30 Clemmons
I assume resetting the gfci only tripped it back off again? My boat is in my backyard and kind of have the same situation. I have a 30a to 15a adapter to an extension cord plugged into a 15a gfci outlet at the house. I had trouble with the house gfci circuit tripping when I plugged into the boat or unplugging from the gfci outlet especially if I forgot to power off the panel first. Would work fine with everything plugged in and resetting the circuit though. Probably not much help but thought I would share.
 
Joe

Joe

.
Jun 1, 2004
8,196
Catalina 27 Mission Bay, San Diego
Remember that you can only have one gfci per circuit.
 
Charles Erwin

Charles Erwin

.
Jan 30, 2012
1,142
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
In the case of 15A or 20A service - a GFCI outlet at the pedestal is common. Common both in the slip and on dry land (at the yard.) In contrast, 30A service is rarely GFCI protected at the pedestal.

So if you have GFCI devices on your boat then is it is likely you will have GFIC nuisance trips if you use a 15/20A service outlet whereas you will not have these trips if you use a 30A service outlet.

If you do not have any GFCI devices on your boat then you should not have any trips. The danger is - if you do not have any GFCI protection on your boat - and you still trip the service providers GFCI outlet you need to find out why because a GFCI trip when the circuit has only one GFCI device within the circuit path means something is dangerous wrong.

Charles
 
Bob 04 H260

Bob 04 H260

.
May 16, 2007
1,509
Boatless ! 26 Ottawa, Ontario
Charles Erwin said:
In the case of 15A or 20A service - a GFCI outlet at the pedestal is common. Common both in the slip and on dry land (at the yard.) In contrast, 30A service is rarely GFCI protected at the pedestal.

So if you have GFCI devices on your boat then is it is likely you will have GFIC nuisance trips if you use a 15/20A service outlet whereas you will not have these trips if you use a 30A service outlet.

If you do not have any GFCI devices on your boat then you should not have any trips. The danger is - if you do not have any GFCI protection on your boat - and you still trip the service providers GFCI outlet you need to find out why because a GFCI trip when the circuit has only one GFCI device within the circuit path means something is dangerous wrong.

Charles
Click to expand
I do have GFCI circuits on the boat but they are only on the outlets in the cabin. None of these trip on the 30 A power cord.
I would think if the main breaker in the AC panel is off they would not have any effect on the 15 A shore power GFCI.
Bob
 
Maine Sail

Maine Sail

.
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
Try a different extension cord. Seen damaged/wet cords cause this before after being run over in yards too many times...
 
heritage

heritage

.
Apr 22, 2011
939
Hunter 27 Pecan Grove, Oriental, NC
A GFCI breaker can trip even if all of your onboard circuit breakers are open. The onboard breakers only break the hot side of the AC system. The neutral side is not broken.

A GFCI breaker trips when it detects a difference in current flowing in the neutral and hot wires. So if you have a neutral (white wire) faulted to ground , the breaker will trip. Some of the older battery chargers may fault the neutral to ground or if you have an older generator that doesn't have a double pole breaker, it could cause the problem.
 
Ron20324

Ron20324

.
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
The polarity light should light (if necessary) with the breaker in the off position. The light's purpose is to tell you to NOT to turn the breaker on.
 
M

mitiempo

.
Sep 28, 2008
922
Canadian Sailcraft CS27 Victoria B.C.
heritage said:
A GFCI breaker can trip even if all of your onboard circuit breakers are open. The onboard breakers only break the hot side of the AC system. The neutral side is not broken.

A GFCI breaker trips when it detects a difference in current flowing in the neutral and hot wires. So if you have a neutral (white wire) faulted to ground , the breaker will trip. Some of the older battery chargers may fault the neutral to ground or if you have an older generator that doesn't have a double pole breaker, it could cause the problem.
Click to expand
The op stated that his panels were turned off. That would mean that the double pole main breaker was in the off position, breaking both hot and neutral.
 
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