wire

michael graham

Can I run 12-2 wire from a 15 amp breaker, to a switch that will then have 14-2 wire out of it to my lights?

itsnotrequired

sure, provided the breaker and switch can handle the #12 conductors.

why are you running #12 though? do you have some lying around? part of an old circuit? voltage drop issue?

andrew79

as long as the wire is fused(breaker) at 15A then your good.

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frenchelectrican

Yeah you can run 15 amp breaker on #12-2 NM however you mention 14-2 so you have to use the breaker on sized on what the smallest conductor you have on that circuit so if you have #14 AWG then you have to use 15 amp breaker ( the only time it will change if you have motour load then there is a specal rules to use this but for now it is not used.)

For myself I rather just run the same all the way thru to keep it uniform in case someone else may not noticed why you have #12 AWG and slap in a 20 amp breaker due you have #14 AWG somewhere along that circuit and that person may not be aware with it.

If super long run sure it is normal to be oversized and I will make sure I leave a note that is a long run so they will know not to put a oversized breaker in there.

Merci,
Marc

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andrew79

depends where they live, we can't use 20A circuits for anything that has a light on it except i think there's an exception for bathrooms. All lighting circuits have to be 15A.

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joed

No exception that know of in residential. Lighting is on 15 amp circuits in Canada.

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gregzoll

Say what?

There is nothing wrong with wiring a lighting circuit with #12, just have to make sure that you note somewhere on the panel, or hang a tag on the wire stating to not replace the breaker with a 20 amp. There is nothing wrong with using #12 with #14. Same with using #10 with #12 or #10 with #14.

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gregzoll

Never heard that before. 20 amp circuits are used all the time when the lighting demands demand #12 for the circuit & a 20 amp breaker. Then again, Canada is a weird country, but has good beer.

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itsnotrequired

i never said there was an absolute problem with this. i don't know what type of breakers or switch the poster has. some equipment may not accept #12 wire. to simply so 'no problem' may not be accurate.

you have to admit running #12 and then changing to #14 is not common. i was simply curious why the poster was doing this. like french said, mixing conductor sizes can cause future problems. leaving a note is nice but not any type of code requirement.

gregzoll

I have never seen a breaker not accept #12. It is #8 that you are thinking. As for mixing conductors, only if someone starts rewiring, but as long as at the panel the wire is protected by the required sized amperage breaker or lesser there is no problem, that is why both of us mentioned about making note for the next person, so that they do not change out the 15amp or smaller breaker for a 20 amp. And yes, it is not a code requirement, it is called a courtesy. Most people with common sense make notes for others, or in the case of using blueprints or schematics, you will see attached sheets with notes or a printed document that references the notes for others that come along to work on the system.

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itsnotrequired

there are several reasons why this may not be okay. where is this poster located? are they talking about aluminum or copper conductors? solid or stranded? is the switch box sized such that there is not space in the box for #12 conductors? at face value, with copper conductors and equipment rated to accept the #12 conductors (solid or stranded), going from #12 to #14 on a 15 amp breaker is okay. but there may be other factors at play that may not make it okay. that's all i was trying to point out. and it is an unusual installation which prompted me to ask why it was being considered. the answer to that may reveal some other flaw in the plan.

electures

Nice thought but not a requirement. Maybe we should leave little post-it notes. LOL

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gregzoll

Never stated that it was. As usual, late to the game, and not reading the whole thread.

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electures

If you were not such an amature I would be amused. I see you are still shovelling your dribble. Someday try actually contributing to a thread instead of just boosting your post count.

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