I have a multi-wire that is very old and doesn't have a ground. I'd like to change this to using new Romex so that AFCI breakers will work. My question is this... Can I band the red wire in my multiwire cable with green tape and then use that as a ground? Of course, I'd band it with tape on both ends....

The alternative is to either abandon the red wire and use a ground from another source in the next junction box (available) or replace the old 12-3 Romex that doesn't have a ground with a new 12-2 also.

Phrased differently: 1. Replace 12-3 w/o ground with two 12-2 that have grounds 2. Replace 12-3 w/o ground with one 12-2 with ground and reuse old 12-3 w/o ground, using ground from new 12-2 in the next junction box 3. Replace 12-3 w/o ground with one 12-2 with ground and reuse old 12-3 w/o ground, banding with green tape the red wire and using that as the 12-3's ground.


  • 1
    Is 12/3 with ground not an option? – mjohns Aug 23 '15 at 13:33
  • I agree with @mjohns. Installing new 12/3 w/ ground, and a double pole CAFCI breaker is also an option (and possibly the best option).. – Tester101 Aug 23 '15 at 13:42
  • Well, I guess the observation I would have there is... If I have to pull another Romex then why pull a 12-3. I can pull two 12-2. Plus, I'm not 100% sure California (CEC) will allow multiwire now. I have to check. But, again, if I have to pull something then option #3 would be most acceptable. In that, I would pull a single 12-2 and either abandon the red wire in the old 12-3 or tape it and use it as a ground. – Alan Aug 23 '15 at 14:35
  • Oh, I also may not have been very clear... The 12-3 I have now does NOT have a ground wire. It is from the late 50's. There are 3 wires total in it: red, black, and white. There is no bare copper ground as you have in modern 12-3 – Alan Aug 23 '15 at 14:37
  • OK... I did more digging. I thought multiwire had been disallowed but I was wrong. I have a ground at the far end already so I can use that (believe that is legal). IF I legally can use a 220V AFCI in a multiwire scenario then that seems like it is the best way to go. – Alan Aug 23 '15 at 14:48

Your Answer

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

Browse other questions tagged or ask your own question.