Triped GFCI Outlet

Mike Finley

I was replacing a vanity light in a bathroom a few days ago and when I touched the neutral against the ground the GFCI outlet on the wall tripped, obviosly they are on the same circuit but why did it trip? I reset it and did it a couple of times just to make sure.

PipeGuy

Even with the breaker and switch 'open', or off, the neutral side of the circuit remains intact and connected to all the other neutral branches in the house. I suspect that when you grounded the neutral wire the GFCI must have detected the very, very minute change in potential that took place as current, from other circuits in the house, strayed from the house's neutral path to ground. Just a guess.

mdshunk

A GFCI will detect a neutral to ground short as part of it's normal test. This sometimes shows up when you wire up a new GFCI and stuff it back into the box, and the bare ground may touch the neutral screw on the side. In your case, it was a neutral to ground short at the vanity light.

Mike Finley

So if I am reading right - it waz suposzd to do dat? That means it is working correctly?

Tom R

Doesn't sound right to me, Mike, - - as far as I know, - - lighting shouldn't be on the GFCI circuit, period. Of course, md gets the final word on this.

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mdshunk

Shouldn't be? Well, there's no code that prohibits that. It is general practice to not GFCI protect the lighting on the load side of the GFCI, but not everyone does this. I've run across it often enough, that I can believe that was probably the situation there. Mind you, GFCI's have been retrofitted at warp speed the last 10 years in existing bathrooms, with varing degrees of care and skill. If the lighting was "after" the receptacle, often the lighting also got GFCI protected as a result of the installer (handyman, homeowner) not knowing how to arrange the connections otherwise. Plus, many of these old vanity lights had a two prong "shaver receptacle" in them. It would be then required to serve this lighting fixture with GFCI protection to also protect the integral receptacle. My preference is to cut these receptacle wires out of the fixture, rendering the receptacle dead.

Tom R

Unless it's been changed since, - - which I doubt, - - try this, - - 1999 N.E.C. [210-11c3], - - Separate 20 amp circuit required for bathrooms (No Lights), - - I do know this is the rule we are required to go by around here.

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jbfan

The code is 1 20 amp to supply one or all bathroom recepticles, or 1 20 amp to supply everything within 1 bathroom.

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Tom R

Hmm, - - I'm aware of the first half of the statement, - - but not the second. Not doubting you, - - it does make perfect sense, - - though I don't 'think' they allow it around here. Good info though, - - thanks.

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Teetorbilt

md, you are really making me feel old. LOL I remember hooking up to the lamp receptacle just like my father did. 2 prongs, no problem, get'er'done. BTW, I'm back to blades and thinking about electrolysis or lasers, I'm over the facial hair thing. Too much wasted time.

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Tom R

Funny, - - to me the definition of 'old' has NEVER changed (yet it never includes 'me'), - - it's alway's been 'my age' + 20 years

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Teetorbilt

Tom, I know what you mean. Brain says 20 but body tells you 50+ later. Takes days too. You think that you are hurting and the next day....it gets worse! I could really do without this 'getting old' stuff.

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Tom R

Ouch!! 'Fifty' is a bad word right now, - - or at least it will be in about a month and a half!!

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Mike Finley

House was built in 1994.

Even better was the fact that the vanity light didn't have a box, it was a wire sticking out of the wall! I added a new work box in order to give the new light something to properly hang from.

I have a hard time believing a builder could have gotten that past the inspector, so I suspect somebody added the vanity light later? That is very hard to imagine since the vanity is 8 foot long double sink with full length wall to wall mirror. Hard to imagine the bathroom would have been built in 1994 without a vanity light. Also the switch for this light is on the wall outside the bathroom, no bathroom door, it is master bathroom suite with 48 " wide arched openning.

mdshunk

Tom, your citation is in error. Here is the actual text from 2005 NEC §210.11(C)(3) which is unchanged from the 99 version you quoted:

210.11 Branch Circuits Required.
(C) Dwelling Units.
(3) Bathroom Branch Circuits. In addition to the number
of branch circuits required by other parts of this section,
at least one 20-ampere branch circuit shall be provided to
supply bathroom receptacle outlet(s). Such circuits shall
have no other outlets.
Exception: Where the 20-ampere circuit supplies a single
bathroom, outlets for other equipment within the same
bathroom shall be permitted to be supplied in accordance
with 210.23(A)(1) and (2).


This text is repeated word for word in the 2003 IRC §E3603.4

In summary:

* If this branch circuit serves that bathroom only, it may serve everything in that bathroom.
* If this circuit also serves a receptacle in another bathroom, it may serve bathroom receptacles ONLY.
* If this circuit serves a bathroom receptacle and also serves lights or receptacles in other rooms other than this bathroom, this is a code violation and has been for a decade or more.

mdshunk

Quite often, if the electrician doesn't know what type of fixture will be installed at the end, he will leave the vanity light wire "tailed out". The "Holllywood strip" type vanity lights often just take the wire straight into the back of them through a romex connector in a knockout. Lighted medicine chests also just take the wire straight into them without needing a box. If the light is the type that does, then the electrician has to cut one in. I leave my vanity lights tailed out for the ruff too until the end, so that I can more perfectly center the fixture with respect to the mirror, medicine chest, or wash basin. I'm seeing your situation as a a "git-r-done" uncaring electrician doing the electrical finish work on the original install.

Since your new fixture needed a box, you did the right thing by installing one. It's usually a flip of the coin when you take a vanity light down whether there will be a box in there or not.

Tom R

Thanks md, - - and my apologies for the error, - - I actually 'cited' it word-for-word DIRECTLY out of the 'Code-Check' book, - - my guess is that the '(no lights)' reference being in parenthesis was their way of condensing/abbreviating the variations and/or local options. Thanks for the correction/clarification.

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mdshunk

I never was a big fan of the "Code-Check" series of books, but I'm sure that they are a great help to many people. The actual code books, besides being only a few dollars more than the code check booklet, contain the actual enforcable text. I prefer to read it for myslef. My local contractor's association puts on a workshop every three years when the new codes come to print to teach about the major changes. If you keep going to the changes classes, you don't really have much to learn in between times.

I like to keep in touch with the latest:
National Electrical Code (NEC)
International Residential Code (IRC)
International Building Code (IBC) [commercial work, mostly]
International Fuel Gas Code
International Mechanical Code
International Plumbing Code
International Energy Conservation Code
International Existing Building Code
International Fire Code

This seems like a big list, but there's tons of overlap, so it's not too bad. If you're doing mostly resi work, the NEC and the IRC are most of the time all you need to worry about.

Tom R

Yeah, I know what you're saying, - - but I like them, they do somewhat cover the basics, - - admittedly, they're the 'code-for-dummies' version.

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Mike Finley

Thanks MD, intersting to know. So what appears to me to be an added light and switch because of the way it was set up is most likely in reality the original wiring from the builder. I didn't realize that you could ever install any light without a box. And yes it was a hollywood strip light that I took out. I'm copying your reply into my contractor's bible for reference in the future, thanks.