# Can I use a section of 12/2 on a 15A 14/2 circuit? [duplicate]

I have 7 outlets on one circuit. It has a 15amp breaker and is wired from one to the other in 14/2 My question is, I have a small(6' section) where I have to change around, and I will need about 6' of wire to connect this outlet. Question is I have a whole bunch of 12/2 romex and want to know if i can use the 12/2 for this 6' section. It is still just outlets in a series. Thanks

It is perfect to use 12/2(or larger) on a 15 amp circuit.

The code only states the minimum size gauge to use on a circuit. 14 gauge is the minimum on 15 amps.

You cannot add 20 amp breaker if any wire is smaller than 12 gauge, must all 12 gauge or larger.

Most devices have a maximum gauge that will fit on it's connection points.

• Label it when done. Subsequent maintainers who see the mixed gauges need to know that you added 12/2 to an otherwise 14/2 circuit, and didn't add 14/2 to a circuit that needs to be 12/2. Mar 31 at 14:19
• In fact for very long runs, as to an outbuilding, voltage-drop rules may mandate 12-ga (or better) for a 15-Amp circuit; and I've often wired my outlet circuits with 12 ga out of an abundance of caution. It certainly is a bit harder to work with, though.
– CCTO
Apr 1 at 20:20

So long as the breaker is 15A, because there is 14Ga wire on the circuit, you can use 12Ga (or 10, or 8, or whatever larger size you like, though it becomes inconvenient in practice) on the circuit as well. 14Ga is a minimum size, and 15A is a maximum size if there is any 14Ga. 12Ga is larger than minimum, and perfectly safe/acceptable.

• Label it when done. Subsequent maintainers who see the mixed gauges need to know that you added 12/2 to an otherwise 14/2 circuit, and didn't add 14/2 to a circuit that needs to be 12/2. Mar 31 at 14:18
• There's no accounting for incompetent "future maintainers" - Competent ones see a 15A breaker and 12 joined to 14 and know that all is well here. The ONLY case where a "note" might be called for is if the 12Ga is connected to the breaker and 14Ga is not visible there. This is a connection between outlets that have 14Ga, so I don't see any need for a "note." It's obvious. Mar 31 at 15:14