GFCI Risks? Update

[BFL13]

Updated 24 March
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Having a new GFCI problem I have been unable to locate in the "receptacle circuit".

While on shore power (from house) The GFCI receptacle on that string itself had power, showing two lights on the tester as "normal", but the GFCI was popped and would not reset. The rest of the receptacles all dead.

The other 120v circuits in the trailer, including the GFCI "galley" receptacle on its own cicuit are ok.

Swapped over to inverter with shore power plugged into that, and now the receptacle circuit is fine and the GFCI button can be reset so everything seems ok. Back to shore power and not ok.

To get a quick fix, I took out the GFCI receptacle and replaced it with an ordinary one, so now everything seems ok even when plugged into the house.

However, whatever was causing that GFCI to pop is still there of course. I checked for that by plugging the trailer into the house bathroom GFCI receptacle and it popped.

So just what is the risk here? If I don't plug into a shore power GFCI receptacle, I would never know, and when off-grid on inverter I would never know.

Hunting for that GFCI would take hours and hours taking out each receptacle I guess, since the usual swapping things around didn't find it. So until I get that ambitious, should I care?

Thanks

[BFL13]

Update #2--Fixed! Well the fault went away, so not known, suspect water in outside receptacle.

The galley GFCI has only the one wire to it and I had it on load (my fault from when I had it out four years ago) Put that on line and now when popped it is dead.

Put the other GFCI in properly this time (I did have the wires from breaker on load) and now it too is dead when popped.

I never would have solved that without the help here--thanks again!
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Update. Tried plugging the trailer into the house bathroom GFCI today and now it doesn't pop. Out in the trailer that circuit (no GFCI now) has power.

But just for fun I tried the GFCI in the galley circuit (not popped) I pushed test and it popped, and pushed reset and it did. Then I tried the tester with it popped and it had power--two lights normal. Drat.

The GFCI in the house does not have power when it is popped for a test.(except for its little yellow light that comes on)

So maybe it was from the rain and now it is dry. Now I have to replace the GFCI and put it in right and also pull the galley one to see if I have it in backwards or something.

[BFL13]

I see some on the P & S site with 5-20Rs. However, looking at the instructions for the Leviton brand GFCI I have in the house, it says they have models with "20a Feed-through rating, 15a outlet rating" and also models that are "20a Feed-through, 20a outlet" So I suppose this P & S one I have is marked 20a for its feed-through and it has the 15a outlets.

Anyway the circuit has 14 wire and a 15a breaker. American versions of this same trailer have 20a breakers instead, according to the owner's manual. Don't know if they have 12 wire and 20a outlets.

The Leviton also has the line terminals on the end where if "up" that would put the outlet ground prongs "up" To me that is "up-side down" 🙂 I might have to add some wire to the short lengths showing in the box to fit on the receptacle if the top ones are supposed to go on the bottom and won't reach. All part of the fun.

[enblethen]

If the fault was between the breaker and the GFCI receptacle, it would have no effect on the GFCI receptacle. It would have effect on the GFCI that or if the rig was plugged into one.
I was looking at the Pass and Seymore website. They have, not sure if yours is one, smart GFCI receptacles that look at the circuit several times a minute rather then like the standard GFCI. I am not sure this is a good or bad thing. Also did not see any true 20 amp GFCI receptacles on their site.

[BFL13]

wnjj wrote:
I guess my previous post wasn't clear enough. I was suggesting connecting only one ROMEX to the line side and then powering up the breaker to see if you have the correct one.

It doesn't hurt anything for the GFCI to be "upstream" so long as the receptacles in wet areas are protected. I'd put it wherever the easiest place to reset it is.

Thanks, I will put it back where it was, which is close to the breaker panel, so that might be the first place in the string and would then protect them all.

It was clear. I would use my meter to see if the wires are "live" instead of hooking up the line end of the receptacle though. Seems like a lot of work using the receptacle.

What if the ground fault is between the breaker and the GFCI receptacle? Would that explain how mine behaved where it did pop but was still live?

[wnjj]

I guess my previous post wasn't clear enough. I was suggesting connecting only one ROMEX to the line side and then powering up the breaker to see if you have the correct one.

It doesn't hurt anything for the GFCI to be "upstream" so long as the receptacles in wet areas are protected. I'd put it wherever the easiest place to reset it is.

[BFL13]

Paul D. wrote:
If you are going to replace the gfci , read the labels carefully. There has been a manufacturing change:
The "line" terminals are now at the top and the "load" terminals at the bottom near the ground (green) . As pointed out by an above respondent the polarity on these is critical for proper operation.

...........

This GFCI receptacle is OEM from the trailer built in Oct 2002.

1. Reading the instruction sheet ( for the first time natch! 😞 ) I see it says for testing your work after installation, that if you get line and load reversed, "...the GFCI will still operate like an ordinary receptacle, but it will not interrupt a ground fault"

That doesn't agree with this thread on that.

2. It is a Pass and Seymour Legrand made in USA, marked "20a 2 pole unit". On the back it is marked line and load but to me they are not "top" and "bottom". The Line (from breaker) is on the end where the outlet on the other side's ground prong is, which I would have "down". Anyway it is marked.

What I never did was determine which of the two cables coming into that box is "from the breaker" so it is 50-50 whether I had them reversed.

I suppose it would be easy to tell which is from the breaker by seeing it is "live" with the breaker on, while the other cable is dead ?

3. This GFCI receptacle was in the entertainment centre. The bathroom receptacle on that same circuit is not GFCI, but I suppose it is on the load side, because it is dead when the GFCI is popped. Should I put the GFCI in the trailer's bathroom (if the box will fit for depth) ? --ie was it a goof that it was put in the entertainment centre ?

The other GFCI is the "galley" receptacle which is on a different 15a breaker. It didn't pop when this one did, so the fault seems to be just on this one circuit.

--The "20a" marker is strange since the outlets have the standard 15a slots, not the sideways and vertical combo slots you see with a 20a. Whatever, in the trailer it goes in a 15a circuit with a 15a breaker.

[vermilye]

For what it is worth, I did a posting a few years back on troubleshooting GFCI's - GFCI Trobleshooting

[beemerphile1]

If everything is working fine except for the ground fault, it could be neutral and ground are bonded somewhere. On mine it was a Romex staple that cut the insulation and shorted/bonded the neutral and ground together. To find the defective circuit I had to open the breaker panel and disconnect the neutrals and then reconnect one at a time.

[BFL13]

Thanks, I forgot about that bonding plug trick.

I also managed to post that in the wrong thread! I'll delete that one.

[wnjj]

BFL13 wrote:
Yes there was a chance it got the outside receptacle wet driving home in the rain the other day. That would be too easy, but fingers crossed. Whatever it is, I will find it eventually 😞

One thing is I can only fix this at home on shore power. Off-grid at our seasonal site, the trailer is on inverter power or sometimes Honda gen power ( with its floating neutral). So there would be no way to confirm the fault has been found, because it won't pop with those power sources.

You can test it with the generator by bonding the neutral to ground. Refer to this post.

[Gene_Ginny]

keepingthelightson wrote:
.... You CAN NOT have two GFCI on the same circuit ....

I have had mine hooked up with a GFCI at the house and one in series with it in the TT for 10 years with no problems.

... over 55 years experience with this electricity stuff ....

[keepingthelight]

The GFCI devices are not in parallel, they are in series.
Yes my mistake. Thus the reason for NOT working correctly.

:S

[BFL13]

Yes there was a chance it got the outside receptacle wet driving home in the rain the other day. That would be too easy, but fingers crossed. Whatever it is, I will find it eventually 😞

One thing is I can only fix this at home on shore power. Off-grid at our seasonal site, the trailer is on inverter power or sometimes Honda gen power ( with its floating neutral). So there would be no way to confirm the fault has been found, because it won't pop with those power sources.

[Gdetrailer]

BFL13 wrote:
Apparently I had the two sets of wires going into the top and bottom receptacles of the GFCI gizmo reversed according to an earlier post, explaining why it still had power although popped.

So it did work anyway to indicate there is a fault and shut down the other receptacles on that circuit, but it stayed on, which was wrong, and would not reset even though it had shore power. It did reset with inverter power (inverter not bonded but the shore power from the house is bonded at the house panel as I understand it )

That must have been me that got it wired backwards some years ago when I had another GFCI fault and I had that whole GFCI receptacle out and put it back in after finding it ok when tried in another circuit. That time it was a wet outside receptacle.

I will get it right this time around!

Meanwhile that circuit still has a fault in it somewhere that I have to find, but I am not in a rush- have other work to do first. (So don't expect any follow-up soon on what the fault turns out to be)

With the help in this thread I have learned some more about GFCIs and should be able to chase this down. Thanks for your interest everybody.

Have you had a lot of rain or melted snow?

My first trailer drove me nuts when it rained and the trailer tongue jack and blocking would get soaked.. The blocking and tongue jack would apparently create a ground loop with the house ground and the porch GFCI would trip every time it rained hard enough to puddle around the blocking..

My current trailer I never had that problem and then I put in a dedicated 120V 30A outlet (which a GFCI is not required in US).. No more worries about false trips..