ground fault circuit interrupter (GFCI) plug trips....

L

localboy

New member
For all you electrical & wiring geniuses....

Our 25 has shore power. Power goes to a circuit breaker board and our two factory installed 110v outlets have a dedicated breaker.

From the factory it was wired:
-from breaker to a GFCI (under the dinette)
-from the GFCI, to a plug behind the pilot seat (long run)

All this appears to be 12 gauge three wire tin.

I have since installed another plug from the GFCI into the "closet" to power our microwave; short run of about 6'. This run is done with 10 gauge, marine approved tin wiring. Upon testing w/ our genset here is what happened.

-GFCI works fine
-new plug I installed works fine
-when I place a load on the plug behind the pilot's seat, the GFCI tips.

WHY? :?

I have re-checked all wiring; all looks fine. I have unplugged the micro, then tried the pilot-seat plug; same outcome.

As usual, mahalo for any/all input. We electrically challenged appreciate it.....[/u][/i]
 
Not sure with your wiring--but if you are using the Honda EU 1000/2000 series, they basically float the neutral (not tie neutral to ground)--and that can cause what appears to be a "weak" reverse polarity. Also may trip GFCI if the neutral and ground are tied to gather in the boat.

Is the plug correctly wired? (hot and neutral reversed?)--that could trip the GFCI if on the generator.

I assume that all works OK on shore power?
 
Just for completeness: in Journey On, there is a galvanic isolator for the green wire before the AC breaker panel. There's also an outlet for the refrigerator hidden in behind the fridge. Yes, that's wired through the Refrigerator switch.

Since you're going through the GFCI receptacle, sounds like you have the power and return wires mixed up, when you installed the additional receptacle. When you tried your new outlet, when there was no current through the outlet, there was no problem. And when you tried the microwave, bingo the current inbalance tripped the GFCI.

Note that on a GFCI, there are IN (Line) and OUT (Load) connections for the power (black) and return (white) wires. That's so the GFCI can compare the power and return currents and if they're not equal, shut the device down. You've got to make sure that the load to the microwave is on the load terminals, same as the load to the helm outlet.


On the GFCI at which I'm looking, there are 5 terminals. Ignoring the green, there is a LOAD end and a LINE end, as well as a WHITE side and a HOT side, 4 terminals total.. So the Black wire from the main breaker goes to the HOT side, LINE end and the White wire to the Shore Power plug goes to the WHITE side, LINE end. The other end goes to any downstream receptacle.

Then check the wiring on the new receptacle, to make sure the power (black) is to the brass/dark terminal on the new receptacle and the return (white) is to the shiny/silver terminal. Green to green. This shouldn't make any difference, just for completeness sake.

Those GFCI devices are a PITA. If it doesn't work after you've checked the wiring, try replacing it. They're cheap.

Actually the lead on the Honda is connected to the generator chassis, and the chassis is floating, in general. Certainly if it's setting on the cockpit floor. Since the GFCI checks the difference in the power current flow, it's irrelevant.

Boris
 
I'll double check tomorrow. Weird thing is, I did not touch the factory outlet behind the pilot's chair, yet it is the one throwing the GF outlet. :?

Oh, and it does the same thing on shore power. I have a dedicated 30 amp "RV" outlet outside.
 
It is possible that the GFCI behind the by the pilot's chair was mis-wired?
Did the GCFI cut off prior to the time you installed the new plug?
Is the GCFI properly wired (with the wire out to the plug behind the pilot chair and the microwave both taken off the same terminals from the GCFI?

Boris, I pulled the circuit for the Honda EU 2000i, and the "ground" on the honda does not connect with the neutral of the output of the inverter. (as it would in a home circuit) Thus the neutral floats--the ground is to the frame of the engine, the frame of entire unit, the alternator block and the inverter block. These "generators" have a engine run alternator, which goes to an inverter to produce 110 V AC. There is a separate "ground--which on the schematic goes to the "Frame ground" This also goes to the green wire of the 110 v plug, thru the frame. Our normal household circuits have the ground and neutral tied together--not true on the Honda EU series. It may be that we are saying the same thing.
 
localboy,
Make sure the the plugs, which I assume you mean u-ground receptacles, are wired in parallel from the "load" side of the GFCI. Make sure that the ground wire on both receptacles is not touching the neutral terminal on the receptacle. GFCI work on the principle that the current in the hot matches the current in the neutral. Any parallel connections or 'touches' of the neutral and the ground will trip the upstream GFCI.
 
Just for completeness sake, here's some comments on the C-Dory outlets.

First, in Journey On the GFCI receptacle is next to the AC panel, under the table. The receptacle up by the helm seat is a normal one. This makes sense since all the current has to pass through the GFCI receptacle in order to have protection. Having the GFCI next to the supply panel minimizes the wire run.

Next, it makes no difference if the downstream receptacles are wired in parallel or series, as long as all the circuits are terminated at the GFCI. Again the rationale for this is that all currents have to pass through the GFCI, which measure the total current and doesn't care how it's routed. If the currents aren't equal, the GFCI assumes there's a return fault and disconnects the power.

So, if either downstream receptacles trip the GFCI, it's a real fault in the load (whatever's plugged in) where the return is shorted to ground. Try another load. If the load is OK then it's either the wiring or a problem with the GFCI.

Or something else.

Good luck and let us know what happens, so we can all learn.

Boris
 
Boris,
I respectfully disagree. If you wire in series, you will drop 120 volts across two or more different loads. Also all receptacles would have to see a load for the circuit to work. I suspect you are confusing daisy chaining with parallel. All outlets, plugs, or receptacles, must be wired in parallel in order to work properly and provide the rated voltage. There are of course exceptions, but nothing you would ever run into in normal applications.
Forrest
 
This is gonna have to wait for later. We leave for Desolation Sound on Thursday morning, and I work the next two days....

I'll F/U once I return and take everthing apart for a good look. We have RARELY used the plug behind the pilot's seat, so it should not be a big issue for our trip.
 
Certainly, Forrest, you're correct. I'm used to thinking in parallel or series and I used the wrong terminology. Your use of daisy chaining is certainly what I meant.

I can't type either.

And. localboy, looking at Desolation Sound is better than looking at a GFCI. Go for it.

Thanks, Boris
 
Mystery solved. Forrest was correct; wired it wrong. Had to do w/ the "load" side of the GFC. Stupid mistake but it's now fixed. Not a lot of room to work and the factory left no extra distance in wire to make it easier. As a solution I just ended up putting another 15a circuit breaker in dedicated for the microwave plug only. $13.99 and about an hour and it's done.

Thanks for the help.
 
starcrafttom":1z0me4q2 said:
forget explaining daisy chains I want to know what F/U was suppose to mean. figure out maybe?
Click to expand...

Follow Up. But my mind initially went to the same place as yours and got quite a chuckle.
 
There are two ways that receptacle can be wired. One is taking the hot (black) side from the GFI socket to the next and to the next etc. So they are all in common black--down the line from the GFI. Same for the white, or neutral, and green or ground.

Now if you took 3 triplex wires off one breaker. The first one to a GFI, and the next to a receptacle, without going thru the GFI, and the third the same, a separate set of wires from the breaker, then the second and third are not protected by the GFI.

In this case, the first are daisy chained, the second instance are not daisy chained, but both are in parallel.

Series is entirely different and normally not used in 110 AC or 12 DC in boats. It is more commonly used in speaker wiring--and there will be a difference in impedance in those in series and parallel.

In local Boy's instance, using a different breaker, from the common 110 volt bus, there will be no GFI protection on the microwave plug.
 
Bob, specifically I was curious about your setup where you said you daisy chained the other outlets to the gfci outlet. I guess that would mean all black wires to a common screw terminal, all whites to a comm terminal etc, kind of a star formation outward to the 2 other outlets.Am I on track?
 
Chucko, this is where it may gets confusing--and perhaps where the idea of "serial" came in. For the GFI to work down the line, there had to be a common connection with the GFI plug. That can be with one wire going to the next plug, and attaching another wire to the next, or it can be a set of triplex wire to each plug from the GFI plug--makes no difference--and since there are usually only two or three plugs in most C Dories, it can be done either way. However you don't want more than two ring terminals per screw--better only one. Each plug should have two screws on each side--the ground is where it can pile up--since there is usually only one ground screw on each receptacle.
 
Back
Top