My outlets are 14-2 NM wire, wired into the attic, is it ok to connect a 12-2 NM wire to the 14-2 wires and connect them to the panel box w a 15amp breaker???

  • Even though it may be legal, why would you do that? – agentp Dec 18 '17 at 17:51
  • multiple issues, id rather not share here...thx I have marked the breaker and the wires in more than one place that it has both 14-2 and 12-2 wires connected.... – Mark Wojtkowski Dec 18 '17 at 18:17
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    I think "not" a duplicate because in this case he has the proper breaker which is really core to the question. – agentp Dec 18 '17 at 18:42

You could use the 12 awg wire on a 15 amp circuit connecting the section that is wired in 14. The only problem and I have found with this in the past where part was wired in 14 but the breaker had #12 , I am guessing that at a later date someone put in a 20a breaker and cooked the 14 gauge wireing because it looked like it was wired with 12 at the panel.

  • that is exactly my concern. I guess there isn't actually a code prohibition to protect against this sort of future confusion. – agentp Dec 18 '17 at 17:49

Yes. There's no problem using larger wire (as long as it fits in any terminals/connectors), since thicker gauge wire can carry larger amounts of current.

  • There is an issue - it is harder to make a good, solid connection between wires of different diameters, especially when using wire nuts (as opposed to a wago). The solution is to be careful, make good connections, and use a wago if you doubt your wire twisting abilities. – Monica Apologists Get Out Dec 18 '17 at 20:39
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    @Adonalsium I've never had any trouble using properly sized twist-on wire connectors. – Tester101 Dec 18 '17 at 21:22
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    @Adonalsium never had that problem before, except when trying to re-use ratty old Scotchloks, which are not made for reuse. And I often mix solid and stranded too. If your nuts aren't working for you, either use modern good ones (e.g. ideal's Wingnuts) and use them correctly. – Harper - Reinstate Monica Dec 18 '17 at 22:58

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