[LDRobinson]

Hi, Folks!

I've posted on here before about an open ground, so don't mean to be a bore - but this is another issue. Sorry for the long preamble I'm about to give, but thought some background might help before my question:

I recently installed a GFI combination outlet / switch (to a vanity light) in a bathroom, where the line was coming to the vanity light via BX cable. The GFI switch installation was a replacement of an old outlet/switch combo that was not GFI - i.e. this was not a new installation. When I did the installation, I noticed that BX cable coming into the vanity light's junction box, so figured it was properly grounded by virtue of being metal clad cable. But when I installed and tested the GFI switch, it tested "open ground". It took me a while - and pulling out the medicine cabinet to get behind the wall - to realize that it was an open ground because years ago somebody had spliced into the main line, which originally had gone to the wall outlet, in order to feed the vanity light. When they spliced, they disrupted the grounding of the metal clad cable. I disconnected the spliced cable, re-routed the original BX cable to the box of the GFI outlet/switch combo, and re-wired the vanity light. Should have worked, right? Well, no. Still getting an open ground reading - and I assume at this point that the same person that spliced into the BX cable in this room also did it elsewhere - so the ground could be broken in any number of places.

At this point, I'm not prepared to go hunting through plaster/wood-lathe walls for possible breaches to the ground on this circuit - and taking it out altogether is not really an option, since I'd have to do major re-wiring to bring power back to the bathroom.

Finally, my question is, what if any are my options to get this circuit grounded? There is a waste stack (metal) running right next to the junction box, but I don't know if the code (I know it varies by locality, but in general... ) allows grounding to a waste stack. Something tells me no, but I'm not sure. I don't have access to water supply pipes in that location without ripping up a tile floor, so short of the waste-stack option, I'm kind of stuck. Any thoughts?

Thanks for your help.

[tkrussell]

What concerns me more, and should you, is that fact that there are buried splices with no boxes in walls. GFI protection at an outlet with no equipment ground is allowed by code, all GFI outlets come with labels that say " No Equipment Ground" that need to be applied on any 3 wire outlets that have no ground. This is allowed per NEC Section 4063(D)3(b).

The ground connection you propose to supplement the missing ground at the outlet is not allowed. If a new cable was to run from an ungrounded outlet, you may installed a three wire outlet and run a separate ground to a grounding electrode, such as city water or a ground rod, but this connection must be at the point the system is grounded not onto any pipe at any location. This is per NEC 250.126(C).

The equipment ground continuity of BX cable must rely on approved connectors onto approved junction boxes. There is no approved method of connecting a wire to the sheathing to extend the ground, and a waste water line is not a approved grounding electrode.

So, without repairing the continuity of ground of the BX by re-connecting the cables into boxes, best you can rely on is the GFI protection, which is much better than nothing.

Hopefully in the future you can muster the means to seek out these open splices hidden in walls to enclose the splices, and at that time you can insure the continuity of the ground, plus insure the splices, if they short out or spark, will entrap the sparks, as intended. Even a junction box with splices cannot be buried, any cover for a box must be accessible.

[LDRobinson]

What concerns me more, and should you, is that fact that there are buried splices with no boxes in walls. GFI protection at an outlet with no equipment ground is allowed by code, all GFI outlets come with labels that say " No Equipment Ground" that need to be applied on any 3 wire outlets that have no ground. This is allowed per NEC Section 4063(D)3(b).

The ground connection you propose to supplement the missing ground at the outlet is not allowed. [snip] Hopefully in the future you can muster the means to seek out these open splices hidden in walls to enclose the splices, and at that time you can insure the continuity of the ground, plus insure the splices, if they short out or spark, will entrap the sparks, as intended. Even a junction box with splices cannot be buried, any cover for a box must be accessible.

Thanks for the advice. I didn't think it was allowed, but good to have the confirmation. And, yes, the prospect of buried splices with no boxes does concern me. I just don't have the means to deal with it right now - especially as it would involve a "search and destroy" mission. But it's good news about being able to get some limited protection from a GFI outlet (with the warning label). Thanks - I appreciate that info. In the mean time, I'm going to see if there is any possibility of running a new, grounded circuit to that bathroom and converting the GFI outlet/switch combo to a straight switch.

All the best,
LD Robinson