PDA

View Full Version : Wiring my whole house with 12awg?



Mary Stitt
08-23-2011, 09:13 AM
I'm wondering whether it's a good idea to use 12awg all over my house. The price difference for the cable isn't much, and I like the idea of being able to use a PA system or power saws in various rooms without having to worry about tripping a breaker. But will I run into problems down the line? I'm wiring lighting on the same circuits as the receptacles in all but the kitchen and laundry room. Are most light fixtures able to deal with 20A? Are 20A receptacles significantly more expensive than 15A? And will I need to use larger than standard boxes to accommodate the #12 wire (my understanding is that the NEC designates a maximum of 9 #12 wires in a standard box, and with incoming and outgoing power plus 12-3 cable going to a light fixture, I would exceed that)?
Thank you for your help!

Jack Feldmann
08-23-2011, 12:16 PM
You can certainly use #12 wire for all the 120V circuits, even if you are going to use 15 amp breakers for some of them. 20 amp outlets will cost a bit more than 15 amp outlets.

Harry Janssen
08-23-2011, 02:05 PM
Mary,I do not see a problem using # 12 wire,except most circuits do not require this gauge of wire.
Why not save the extra cost of wire,and if you think you made need more power in certain areas,why not add less outlets per breaker,or add in few more breakers,than required

Jerry Peck
08-23-2011, 05:06 PM
You can certainly use #12 wire for all the 120V circuits, even if you are going to use 15 amp breakers for some of them. 20 amp outlets will cost a bit more than 15 amp outlets.

Except that you can install 15 amp receptacles on those circuits.

Mary,

Using #12 instead of #14 for 15 amp circuits makes sense in that you don't have to worry much about derating for the various reasons, nor do you have to worry much about voltage drop.

I had a builder of multi-million dollar homes I convinced to run #12 for all 15 amp circuits, I couldn't convince him to run #10 for the 20 circuits (which is good for all the same reasons) because his electrician kept complaining about about it being more difficult to handle the #10 wire on the receptacles and switches terminal (the electrician was correct, but he just didn't want to spend the time, even though the builder offered extra money for it). Of course, box fill and other things would crop up using all #10 and #12, but that could be addressed too. I usually prevailed in those improvements because, in the overall scheme of things on those types of houses, the cost was negligible.

Besides, most circuits were 15 amp circuits anyway, so at least most of the circuits were upgraded to a larger size wire. :)

Jack Feldmann
08-23-2011, 05:28 PM
Jerry,
I was answering her question about the cost of 20 vs 15.
JF

Jerry Peck
08-23-2011, 05:38 PM
Jerry,
I was answering her question about the cost of 20 vs 15.
JF

Jack,

Yes, there is a cost difference between 20 amp and 15 amp receptacles, but she can put 15 amp receptacles on 20 amp branch circuits which have two or more receptacles (as most circuits do have) as long as the maximum load is 12 amps or less (which would be likely on multiple outlet circuits), as such, there would not be a cost difference (if she were to take that option, which, I agree, was not her question)

I was just offering it as an option to her question as there would not be a cost difference. I suspect she did not consider or know of that option.