[whatrymes]

Hey:

We have a 20 amp dedicated circuit upstairs that only serves a small A/C unit (4.2 amps) and is really overkill. The cable is in a perfect location for me to tap into for an outside motion light and switch. I really prefer using #14 cable for several reasons.

Is it OK to splice into this #12 cable provided of course I switch out the breaker to a 15 amp breaker?

Thank you

 

[AllanJ]

Yes you can mix 12 and 14 gauge wire with a 15 amp breaker on the circuit.

But it is not recommended because the next homeowner or electrician may be confused and put a 20 amp breaker on it again.

Confusion can be reduced if, down in the panel, you splice on a short length (pigtail) of 14 gauge wire to the incoming 12 gague wire in order to attach to the breaker. Also put a label on that circuit wire.

It would be much better to add on using 12 gague wire since there is no telling whether more electricity won't be used on that circuit in the future.

 

[Clumsy Hamster]

I agree with the previous poster. Just use 12 gauge wire and you won't need to worry. It isn't recommended to connect 14 to 12 as 14 wire isn't meant for 20 amp breaker. Its max load is 15 amps.

 

[frenchelectrican]

This done quite few time but myself I rather run all the rest the same size as exsting conductor if possable but if have to downsize the conductor for some reason then you have to mark it at the load centre to forwarn that it have diffrent conductor in there.

It the same way I do with oversized conductors I mark them down to warn them it is used for long run to deal with voltage drop.

Merci,
Marc

 

[whatrymes]

This done quite few time but myself I rather run all the rest the same size as exsting conductor if possable but if have to downsize the conductor for some reason then you have to mark it at the load centre to forwarn that it have diffrent conductor in there.

It the same way I do with oversized conductors I mark them down to warn them it is used for long run to deal with voltage drop.

Merci,
Marc

Good point Marc, thanks. I'll think on it some more.