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-   -   20 Amp circuit goes to 12 guage wire that 14! (

chrisnp 12-02-2009 10:21 AM

20 Amp circuit goes to 12 guage wire that 14!
Hi, Im a newbie, but I'll save introducing myself till I get home (I'm writing from work).

I know my subject line sounds scary, but here is the whole story -

My mother's house has a history of do-it-yourself amateur home improvements by a variety of neighbors, relatives, and yes, me. As part of an ongoing kitchen remodel, She recently had a new larger electrical panel installed. The old pannel had some piggy-backed wiring and other scary stuff. I assume the electrician (a pro for once) simply connected the 12 gauge wires to 20 amp breakers, and 14 guage wire to 15 Amp breakers.

I volunteered to put the can lights in for the remodel. While doing so, I realized the circuit I am working on goes from a 20 Amp breaker (at least it does now) along a 12 guage wire untill it reaches a bank of three light switches. above the light switches, it becomes three parallel 14 guage wires until they reach a gang box in the attic.

My question is - since the lines above the switches are only going up to lighting, is the mix of wire unsafe? There are no outlets or anything else along the circuit to draw power, and I plan to use three to four can lights per switch. It would really be a bear of a job to pull out the old wire or try to fish in some 12 gage beside it if it really does not matter.

Also, I plan on using some scrap 12 gage wire to complete the job, so the result would be 20 amp breaker to #12 wire to switch to #14 wire to gang box to #12 wire to lights. the part from gang box to lights will await till your reply.



travelover 12-02-2009 11:29 AM

I think the right thing is to make it safe. You could pull the 14 gauge wire off that circuit and add it to another 15 amp circuit or replace the 20 amp breaker with a 15 amp breaker.

chrisnp 12-02-2009 05:12 PM

Doh. I was so worried about the huge job of possibly tearing out wire that I didn't think of the obvious solution of just putting in a 15 AMP breaker. I would hope that anyone in the future who saw a 12 AWG wire inserted in a 15AMP breaker would check what was on the circuit before changing it.


joe cool 12-02-2009 10:22 PM

Why not fix it now? Are you going to get a better opportunity than during a remodel? Do it for Mom.

lou19604 12-19-2009 10:39 PM

For starters you should be adding up the watts from the lights. However in a past job i did what you did. then the inspector showed up and i had to tear everythig out . reason being is. The breaker will allow 20 amps thru, the 12 ga can handle that, the 14 ga is made for 15 amp. amp x volts = watts. an old electrcian once told me just cause your not using 20 amps dosent mean it aint there. HOWEVER I AGREE CHANGE THE BREAKER.

chrisnp 12-20-2009 03:42 PM

Thanks everyone.

Although replacing the breaker would have been easier, what I ended up doing was tearing out and replacing the 14 ga wiring and replacing it with 12. I went along with Cool Joe's observation "what better time than during a remodel?" My reasoning was that most of the wiring was already 12 ga, and who knows how someone might want to modify the circuit in the future.

I'm probably showing my ignorance here, but when I was still thinking of just installing a 15 amp breaker, I looked at my mom's brand new Seimens Pannel, and I could not figgure out where the service disconnect was. What I'm used to seeing is a breaker pair with the total box amperage on it - that's not on this one. I took the face plate off the box to see where the wires that would feed the main breaker were, and it looks like they go to right into the bars that feed the breakers - could that be right?

The new pannel was put in by someone who I was told was a professional electrician.


Parrothead 12-24-2009 09:48 PM

Yes that could be quite right. If the feeders are directly on the busbars, then it is technically a subpanel, and you have a main disconnect outside the panel box. It could well be outside, near the meter. This is unusual, but there are times when services are installed that way. Just follow the feeder wires back to the meter, and you should find the disconnect somewhere- either outside, or within 8 feet of where they enter the house.

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