Running 12-2 Romex cable from the electrical panel to a J-box located in attic. J-box will connect two GFCI outlets and extend a 14-2 cable to the ceiling light fixture box, where other 14-2 cable will be used for a switch.

Circuit breaker is 20A.

Is that OK? Is it code compliance?

  • The answer is NO, see answers below but 14 gauge wiring in the circuit requires a 15 amp breaker. If you spend a few dollars more and use number 12 wire you can use the 20 amp breaker.
    – Ed Beal
    Commented Feb 10, 2019 at 11:01
  • Can you use a 14 gauge GROUND wire for a 20 amp breaker? I can't imagine it would heat up before the breaker can trip, but is it ok for code?
    – Brain2000
    Commented Nov 22, 2022 at 23:13

3 Answers 3


You have to use the rated cable (in this case, 12 AWG), or larger, throughout the circuit. Either use 12/2 everywhere or use a 15A breaker.

Keep in mind that if you use 14/2 and 12/2 in the same circuit with a 15A breaker then there is a risk of confusion in the future if someone looks at the 12/2 coming out of the breaker and thinks "its 12 AWG, I can upsize to 20A" and doesn't realize there is 14/2 elsewhere in the circuit. So all 12 and 20A or all 14 and 15A is preferred, but mixed 12 & 14 and 15A is code compliant.

  • 1
    Agree it is a bad idea but on a 15 amp breaker it would be code compliant.
    – Ed Beal
    Commented Feb 10, 2019 at 11:03

NO! You cannot use any 14 gauge wire on a 20 amp circuit. This is true, even running to a light fixture that has smaller wires built in. The wires built into the fixture are allowed as part of a manufactured assembly. However, any added wire must be appropriate to the circuit breaker protecting the wire.


Not with that breaker, no. But just change the breaker to 15A. Leave the sheath on the cable about 6" coming into the service panel, and sharpie "14 AWG 15A" on it, so nobody is confused and puts it on a 20A breaker by mistake.

As far as "two GFCI outlets" right next to each other, don't do that, it's a waste of $15. Fit a GFCI outlet and a plain outlet. You will notice the GFCI has tape on its LOAD terminals. Never, never, never remove that tape to solve a wiring problem, find another way to solve it, hint: pigtails. However, any GFCI device is able to provide GFCI protection for other loads too, and that is the only proper use of LOAD. Since you want your other outlet also protected, feed it from those LOAD terminals.

  • Depending upon where the GFCI outlets would be, having two separate outlets may be more convenient than having a GFCI protect an ordinary outlet. For example, while having a GFCI in one bathroom protect an "ordinary" outlet located in another bathroom might not violate code, I would think that the improved clarity of operation resulting from having a separate GFCI in each bathroom would be worth the extra cost.
    – supercat
    Commented Sep 28, 2020 at 17:09

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