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#16644 - 11/14/02 01:50 PM Must all grounds in box be tied together?
stevegalus Offline
Member
Registered: 11/01/02
Posts: 14
Loc: Santa Ana, CA USA
Someone mentioned in an earlier post that all grounds in a box should be tied together. I hope there are some exceptions.
I have switch loop (12/2 NM) from a GFCI circuit that shares a switch box with switches on a different branch circuit. Combining the grounds causes the GFCI circuit breaker to trip so I taped and capped the bare ground for the switch loop. The switch is still grounded with the ground on the other branch circuit.
Is this OK? If not, is there another solution?
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#16645 - 11/14/02 02:07 PM Re: Must all grounds in box be tied together?
rmiell Offline
Member
Registered: 11/09/00
Posts: 242
Loc: La Junta, Co. USA
It sounds like you have a equipment grounding conductor touching a grounded(neutral) conductor somewhere in the circuit. That is what is causing the gfci to trip. All equipment grounding conductors within a box, shall be spliced together, no exceptions.

Rick Miell

How does everyone read 250.148 concerning tieing installed egc together or to the box? Does this mean we have to ground the box in every instance, or, if the wires are spliced together, that is all that is needed?

[This message has been edited by rmiell (edited 11-14-2002).]
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#16646 - 11/14/02 02:33 PM Re: Must all grounds in box be tied together?
nesparky Offline
Member
Registered: 06/21/01
Posts: 642
Loc: omaha,ne
To me 250.148 requires any circuit whose conductor(s) are spliced or terminated in a box to have the EGC ground the box. It does not require circuits only passing thru the box to have the EGC ground the box.


If a GFCI trips eithr the ground has current on it or the neutral has different current on it than the hot. Multi wire circuit maybe?

[This message has been edited by nesparky (edited 11-14-2002).]

[This message has been edited by nesparky (edited 11-14-2002).]
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#16647 - 11/14/02 03:20 PM Re: Must all grounds in box be tied together?
electure Offline


Member
Registered: 12/24/00
Posts: 4259
Loc: Fullerton, CA USA
There is an exception, and that would be an isolated ground conductor. Although it's not applicable to this case, it does exist.
Rick, from what I see, unless another conductor is spliced within the box, it doesn't have to be bonded to the box.. but I do it anyhow, it's easy insurance for the grounding path...S

[This message has been edited by electure (edited 11-14-2002).]
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#16648 - 11/14/02 04:32 PM Re: Must all grounds in box be tied together?
caselec Offline
Member
Registered: 04/14/02
Posts: 558
Loc: San Jose, CA
Steve

It sounds like there is a problem with your wiring somewhere. All equipment grounds should get connected together and this should not cause a AFCI or GFCI to trip. Neither of these devices look for current on the equipment ground they are only looking for an imbalance on the hot and grounded (neutral) conductors. Is an equipment ground run with the GFCI circuit conductors? It sounds almost like the equipment ground is not connected in the panel but is connected to the neutral wire of the circuit somewhere.

Curt
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#16649 - 11/14/02 05:02 PM Re: Must all grounds in box be tied together?
electure Offline


Member
Registered: 12/24/00
Posts: 4259
Loc: Fullerton, CA USA
OK,Shut off ALL the power. Unplug everything, and make sure all switches are off. Pull all of your neutrals off the bus. (Except the one from the service)
Check each of them from the white wire to the bus for continuity.
If you get continuity, that is your problem circuit. The ground and neut are touching each other somewhere.

[This message has been edited by electure (edited 11-14-2002).]
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#16650 - 11/15/02 09:03 AM Re: Must all grounds in box be tied together?
stevegalus Offline
Member
Registered: 11/01/02
Posts: 14
Loc: Santa Ana, CA USA
Thanks to your responses, after hours of searching for the problem, I finally found it.
These circuits are run off of a subpanel so checking for a short between nuetral and ground was easy. I just disconnected the ground and neutral runs back to the main panel and measured the ground/neutral resistance. No shorts. Then I wired all of the grounds together in the box that was previously causing the AFCI to trip. No problems. The breaker did not trip. But it had before, when there were no walls and absolutely nothing on any of the circuits. Except one piece of equipment - an old radio that I was using. Sure enough, I plugged it in and the AFCI tripped. Turns out it has a ground fault.
Thanks for the help.
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#16651 - 11/15/02 11:44 AM Re: Must all grounds in box be tied together?
SJT Offline
Member
Registered: 07/24/02
Posts: 241
Loc: PATCHOGUE, N.Y.
Don't forget to straighten out the grounds that you had talked about in your original question about the grounds. (the ones with the tape on it)
Take care
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#16652 - 11/15/02 06:01 PM Re: Must all grounds in box be tied together?
mj Offline
Member
Registered: 06/10/02
Posts: 186
Loc: meriidian, ms
you need to phase-out all of your circuits. there sould be and egc with each circuit
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