Why does the inspector care if I use 12 ga wire for a 15 amp line? I bought a large roll of 12 ga several years ago, which I figured would bbe good for all 120 wiring I will be doing. A buddy borrowed a length of wire to put in a new addition. The new inspector just told him that 15 amp lines can't have 12 ga wire. Makes no sense to me.
Sounds like a inspector that that doesn't know the codes you can over size your wire to a certain degree for the breaker but you can not over size the breaker: example if your running a line 250' from the panel box you could have voltage drop so if said device requires 12 amps you could run #12 wire and put it on a 15 amp breaker
We use 12 ga on 15 amp breakers all the time for long runs.
I could see them balk if you were doing a 250í run of 14 on a 15 amp circuit but 12 is actually overkill.
Itís like hooking up a ĺ inch hose to 3/8 copper youíre not going to get any more water than can pass through the pipe.
You most certainly can run 12ga for 15amp circuit. I do it all the time at work and for side jobs just depends on what I have on hand. At work I never use anything less than 12ga for electrical wiring. Would be interested in hearing the inspectors reasoning.
the thrill is not in the kill, but in the experience
I will be wiring an addition in a couple months and plan to run an extra circuit to my attic for a vent fan and a couple lights, just make them all 20 amp lines?
In several other states, inspectors are full time county employees. Not part time consultants hired to work for a couple of scattered townships. The consultants just aren't as accountable as pubic employees for knowledge of the codes they enforce. I'd prefer a full time county inspector over the part time private inspectors.
House wiring is all based on amperage use potential,your only allowed x amount of outlets or lights per circuit if your load will be less then 80% of 15 amps then you can use 14awg the only place in a home besides appliances, and mechanicals that require 12 awg no matter your potential draw is the kitchen and dinning room all other convenate outlets can be 14awg. But to be safe like your attic your talking about you can pull a 12 wire and you have 20 amps available for future use so if you use it for a couple lights and a fan you might have 7 or 8 amps used and the 12 wire would allow you to have amps available for future use ex soffit motion lights,ceiling fan in a room below many other options but once you put that circuit on a 20 breaker you must continue with #12 wire