gfci receptacle won't reset at installation

[navakahn]

just installed a gfci receptacle in the kitchen. it wired properly with regards to line and load, but when i press the reset, it trips immediately. thought it might be a faulty receptacle, so i replaced it with another and got the same result.

this is the first time i've had such a problem - the other gfci i've installed have all either been dedicated circuits or at the end of a circuit, and i've had no problem. i read somewhere that when there are receptacles that follow it, one can sometimes experience "nuisance tripping". is this the same thing? what can i do to solve the problem? i'll double check to see if all the boxes/receptacles which follow the gfci are grounded - could that be the problem?

i'd appreciate any help.

thanks,
jason

[bkrahmer]

You can feed ungrounded outlets with a GFCI, so that isn't the problem. Make your testing as simple as possible. Disconnect your load wires, and test again. If it works, work your way downstream to the problem. If it still trips, maybe your hot and neutral are backwards.

[navakahn]

thanks for the help. i tested the gfci before i put the load wires in, and it worked fine - no reversal of the hot and neutral either - so the problem must be downstream as you suggest.

i know the circuit shares a neutral with another circuit - my electrician said that this was normal for the wiring when the house was done and didn't advise rewiring. could that be the problem? if so, what types of solutions might work?

i can think of two:

1. rewire the circuit so that it has its own neutral. i'd like to avoid this if possible.

2. replace the box with a larger box and run separate loads to the line of the gfci and downstream. in other words don't use the load. if this is fine, i'd probably go this route since i don't need the gfci downstream.

but i'm open to other solutions.

thanks,
jason

[roger g]

I have been fooled a couple of times by these receptacles. I found that I hadn't pushed them in far enough with enough ooomph. My finger are probably too fat so I use the rubber end of a pencil and push really hard, and I mean hard. Also I found or at least think I've found that I can't reset them after it blows. It seems it need some time to cool off. I think.




roger

[Sparks]

jason, you gfci will trip if your neutral is shared in the manner you describe. The gfci's circuitry is designed to detect a current imbalance of 6 milliamps between the hot and the neutral. The imbalance is what causes a gfci to trip. GFCI's and AFCI's cannot be wired on circuits that share neutrals with other loads. What I would do would be just pigtail your conductors in existing box and feed line side of gfci, the loads downstream would be fed from your pigtails, not the load side of gfci. As you know, these loads would not be protected, so make sure they are not required to have gfci protection. The gfci would now not be detecting any imbalance downstream.

[navakahn]

thanks, sparks. that sounds like the solution. of course, it means i need to switch out the box, but i suppose that's a better solution than rewiring.

[Emer Construction]

Sparks
Does that mean that I can't feed my two kitchen circuits with 12/3?

[bkrahmer]

Where did that question come from? :) Why would you want to use 12/3? If you are wiring a new kitchen, you should use two circuits of 12/2 with 20-amp GFCI breakers. And they can't power anything outside of the kitchen.

[Emer Construction]

It's a long run over a cathedral ceiling. thought I could get away with 12/3. Guess not.

[bkrahmer]

Oh, I see what you're saying. Put both phases of hot with a shared neutral through 12/3 too feed two different circuits. It makes sense. I'm thinking it would be a good way to feed 120 and 240 on one wire (but not two circuits, guess I know that GFCI's wouldn't work on such circuit with any other loads).

Sparks can probably tell us that it's banned, I'm pretty sure it would be frowned upon and likely not acceptable.

[Sparks]

12-3 could be used but personally, I wouldn't being that there are gfcis involved and you may run into complications using either gfci breakers or receptacles. I would stay away from this practice although I don't recall NEC strictly prohibiting this. Some electricians stay away from sharing neutrals altogether because of the risk that if you lose the neutral you could apply 240 volts to your 120v loads under certain circumstances.
Jason, if your existing box is that small where you can't pigtail you have a couple choices. You could just shut-off power and insert sawzall blade between side of box and wallboard and cut off nail-on brackets (real easy to do, just be careful to not damage wall) pull out old box and install a deeper plastic "old work" box into existing hole (enlarge hole a bit) and tighten wing screws ( I prefer this method ) or you could install a surface mount box attached directly to existing box with 6/32 screws (Miremold brand works well for this). Either way, installing a deeper box is an easy task if it's needed. I commend your thinking on this as most would just jam the wires in and be done with it hoping nothing shorts out.

[Sparks]

Jason,
I almost forgot because they're hardly used but Leviton and some other GFCI receptacles have 2 slots for each termination point so you probably wouldn't even have to worry about a bigger box. Just connect two hots and two neutrals both to the line side of GFCI, these are listed for that purpose as there are two slots available. Just do this and pigtail your grounds with a solderless crimp connector (using proper crimp pliers and butt connector) and I think you'll have ample room in any box that I've seen. Now you'll be accomplishing the same thing but without any wirenuts and pigtails taking up room in your shallow box.