2

One of my circuits has a compromised ground wire, by something along the route of its cable ( like a nail or something ) so it's not grounding properly. If it has only one receptacle ( dishwasher + garbage disposal ) and that receptacle has adjacent ones from different circuits that have a functional ground, can I extend their ground to it?

Additionally, I also have a non circuit ground wire nearby that I use to ground my outside cable service box as well as a gas outlet that uses a flexible yellow extension hose ( that somehow requires to be grounded in my area ). If I can't use the ground wire from another circuit, can I connect to that from this receptacle ? I can use a wire that has green insulation going between the receptacle and this independent ground.

1
  • 1
    I'm not a code expert, someone else here will help with that. Assuming your circuit in question is 20 amp and the one next to it is also 20 amp (12 gauge wire) I would at least for the short-term tap into the adjacent ground. It will be better than no ground at all until you get an answer on codes. I really doubt tying into a non-circuit ground wire would be well received by inspectors. Also, if the adjacent circuit is only 15 amp (14 gauge) then that's verboten.
    – HoneyDo
    Apr 12 '20 at 21:06
3

Apparently the answer is that it's okay to ground your 20 amp circuit to another 20 amp circuit next to it.

The key is the gauge of the ground you're tying into has to be as large or larger than the original circuit. So your 12 gauge ground on the compromised circuit has to tap into another circuited ground that is at least 12 gauge.

2
  • Yes, the adjacent is also 20A. You think I can just run an uninsulated piece of ground wire pulled out of a Romex cable or should get a piece of 14 gauge wire with green insulation?
    – amphibient
    Apr 12 '20 at 21:41
  • 1
    @amphibient -- needs to be 12AWG, but bare wire works Apr 12 '20 at 22:17
2

When you have a broken ground wire for reasons you do not know, that's alarming. On Romex, the ground wire is in the middle of the cable. That means any nail which broke it probably also pierced the hot or neutral wire. That means the nail could be energized. You would be better off doing some testing to figure out where that happened and/or replacing the entire cable.

You should also make sure you aren't dealing with a multi-wire branch circuit (MWBC). That can make your numbers not make sense, and make you think things are broken that aren't actually. It's very common to run a MWBC to power dishwasher and disposal. An MWBC typically has a cable with a black and red wire as well as white and ground, and goes to 2 breakers. The 2 breakers must be phased correctly and have a factory supplied common shutoff bar so they throw together.

1
  • 2
    That is exactly the case, I determined that the current goes from the black to the ground at the breakage point. Fortunately, I also discovered that happened at the knockout where the cable enters the panel, probably as a result of a sharp entry angle,, not a nail. So I have resolved the mystery
    – amphibient
    Apr 13 '20 at 1:34

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.