is it ok to run 15 amp breakers on 12/2 or 12/3 wire?

Question

My new home was wired with all 12/2 and 12/3 wire, and on all the charts i see tell me if you have 12 gauge wire use 20 amp breakers

Answer 1

OK..... pay attention........ the other people that answered this question are COMPLETE IDIOTS. It is absolutely perfectly fine to run 12/2 or 12/3 wire on a 15 amp line. In fact, that is what you SHOULD be doing. They only developed 14/2 and 14/3 wire for economical reasons (cause it's cheaper than thicker wire). Good electricians don't even bother with that crap anymore cause it's only usable on 15 amp circuits. You should not bother with 14/2 or 14/3 wire altogether. There is NEVER an increased fire risk when using thicker wire on a smaller amperage circuit. The person that said that is a complete friggin' idiot. It is the exact opposite..... that is........ there is an increased fire risk when using THINNER wire on a higher amperage circuit. Therefore, for example, you should never use 14/2 or 14/3 wire on anything above a 15 amp circuit. In fact it's illegal. You can ALWAYS use thicker wire on smaller amperages. It's better for numerous reasons....... thicker wire will carry the current better and it will REDUCE the fire risk because the wire will not get as hot. I repeat....the person that said using thicker wire increases the fire
risk is a COMPLETE IDIOT. Thank you. By the way...to add one other thing....... the reason you've read "on 20 amp circuits, use 12/2 or 12/3 wire" is because they're indicating to you the MINIMUM gauge (thickness) you can use. You can use anything you want that is thicker than that but it's more expensive and tougher to bend. Just to give you some additional information..... sometimes on large houses where there are long runs of cable, they will use heavier gauge wire on circuits that normally would take a thinner gauge. The reason for this is over long distances (over 100 feet or so), the ability of a given gauge of wire to carry as strong a current diminishes. To counter this problem, they will use thicker wire so the current can flow more freely. Therefore, a 20 amp appliance for example that would normally take 12/2 or 12/3 wire might be bumped up to 10/2 or 10/3.

Answer 2

No you should either use a 20 amp breaker and 20 amp recepticles or if you use a 15 amp breaker then use 14/2 or 14/3 wire. Too heavy of wire creates a fire risk. If your new home was wired to code, this seems quite odd.

Answer 3

12-2 Wire

Answer 4

stick with 20 amp.........

Answer 5

It is absolutely ok