I need to repair a 14-2 run of romex coming from a lighting circuit. Can I use 12-2 for the repair run?

Question

I have 12-2 wire on hand. The actual damaged 14-2 wire I am replacing goes to a light switch. Then it is pigtailed to other 14-2 wire that goes to other lighting and receptacles on a 15 amp circuit breaker. Someone told me that according to code you can add 12-2 to 14-2 as long as the circuit breaker is 15 amp, thus protecting the 14-2 wire from getting hot. Thanks for your input.

Answer 1

You are correct. You can replace a smaller (14) wire with a larger (12) wire. No problem at all. It is also correct that you need to protect the 14 wire with a 15 amp breaker.

Answer 2

You need to keep all the wire the same size as the breaker rating so if it is a 20 amp you have to keep it as 12/2 but if you wanted to you could change the breaker to a 15 amp and then you could use 14/2 , this is a good idea if you have to use a lot of wire since 14/2 is a lot cheaper then 12/2 and a breaker is only about 5 dollars

Answer 3

You can go up on size after the breaker, not down. good rule of thumb.

Translation. you can put all the 12/2 you want on a 15 AMP breaker, but don't put 14/2 on a 20 AMP, it will burn up

Answer 4

I dont see a problem as long as the breaker is rated 15 amps.

Answer 5

It's ok to use a larger wire size in your application. 14-2 is typically used in lighting circuits while 12-2 is used for outlets but again you will be fine.

Make sure your connectors are good and I suggest using electrical tape over the wing nuts.

Answer 6

Yes you can. As long as you do not change the size of the breaker, you will have no problems.

Answer 7

No problem going up in wire size.
There might be a code problem with 'box fill`,
(number and size of wires permitted in a given box),
but if you can get it in, who's looking?