Oversizing Branch Circuit Conductors

Status
Not open for further replies.
P

Profane2

Member
Location
Bay Shore, Long Island
Could I be Wrong for running 12/2 homerun to a bathroom exclusively to use as my lighting circuit and putting it on a 15A breaker. Meanwhile coming off my switches wit #14 to my fixtures. Where in the NEC does it indicate that
oversizing your homerun is unacceptable?
 
Well . We ran 2 -#12 to each bathroom. One to satisfy my GFI Protected Outlet circuit . and I dont see the necessity to make the lighting circuit a 20A
circuit. I mean I see wat you mean . But my curiosity is more towards whether not I'd be wrong to "switch gears" if I just called what I did "oversizing my Homerun"
 
There is nothing wrong with using larger conductors for part of the circuit as you have done. It is done frequently to reduce voltage drop.
 
Do the next guy a favor, label the #12 in the panel with something like "#14 downstream, 15A Max CB!!!". If somebody puts in a gen-tran panel, remodels, swaps breakers, etc, you will have #14 on a 20A. We can't expect the next guy to open all the downstream boxes to verify a #12 all the way through.

Or you could just use #12 for that little 15' run from the switch to the fixture! Probably would be cheaper than the time to make a label.

mike
 
I guess its a mute point now that you already have the wire run, but for next time, remember you can hit the lights in that bathroom with the same circuit as the GFI, as long as this circuit remains solely in the bathroom
 
mhulbert said:
Do the next guy a favor, label the #12 in the panel with something like "#14 downstream, 15A Max CB!!!". If somebody puts in a gen-tran panel, remodels, swaps breakers, etc, you will have #14 on a 20A. We can't expect the next guy to open all the downstream boxes to verify a #12 all the way through.

Or you could just use #12 for that little 15' run from the switch to the fixture! Probably would be cheaper than the time to make a label.

mike
Click to expand...

We can and should exspect any electrician to not up the breaker size just based on conductor size.However i do think a label would be nice.Take the suggestion of 1 circuit to feed a single bathroom as long as its a normal bath.Have seen some masters that needed 3 or more circuits.
 
I put a note on the panel cover saying the breaker sizes are what they are for a good reason and if someone doesn't understand derating or voltage drop they shouldn't mess with them.

Older places with small 2" deep boxes may be compelled to use #14 for switch loops (maybe even 14-2 AC) unless you want to put in a new box...which can be problematic with shallow plaster/lath walls.
 
Status
Not open for further replies.
Top