switching exhaust fan with 12/3

Status
Not open for further replies.
I

iwirehouses

Senior Member
I know that inspectors arn't very sure about 12/3 circuits themselves. Other then the small appliance circuit, using 12/3 is kind of up in the air. I'm wondering though, if anyone has ever had a problem with switching an exhaust fan/light combo with 12/3 or the equivelent. The fan may have heat and a nightlight as well. Instead of running four 12/2 cables, I think it makes much more sense to run two 12/3's, am I wrong?
 
Why not install a short section of conduit, and install enough conductors (six) to do the whole job?

Black-White-Red-Blue-Orange-Green


 
iwirehouses said:
Instead of running four 12/2 cables, I think it makes much more sense to run two 12/3's, am I wrong?
Click to expand...

No you're not wrong. I have always tried to consider cost and resource savings in a wiring lay out and this is a method I would (actually have) definitely use.

Roger
 
I normally have 12/4 MC on board and if that where not enough conductors a length of 1/2" flex would would work fine.

I can't imagine four - 12/2s entering those small JBs
 
We use 12/4 NM cable for these applications. One cable in the switch box and one in the fan. Anything more than that in the minuscule fan box is a nightmare.
 
We have 4-wire romex, but the problem here is you have 4 different switched loads and there ain't enough conductors present to do the job.

You need 4 hot conductors, and a neutral, plus a ground. ..:wink:
 
Very few residential guys even own a bender.Mc is ok but there is 12-4 nm now.Residential is about speed so i sugest a couplke runs of 12-3 or 12-4 nm.Now if thats too confusing to make up then perhaps we have bigger problems.Phase tape should do the trick
 
iwirehouses said:
IInstead of running four 12/2 cables, I think it makes much more sense to run two 12/3's, am I wrong?
Click to expand...

Wouldn't that be a violation?


I asked this question over a year ago in regards to a fan/light/nightlight unit(Hunter).
I can't remember the article number....Infinity may have answered it :confused:
 
The only violation might be tying all the neutrals together in the fan unit. If you are running two neutrals in two cables, the loads on the read & black need to correspond with the neutral in the cable. 300.3(B)
 
iwirehouses said:
I know that inspectors arn't very sure about 12/3 circuits themselves. Other then the small appliance circuit, using 12/3 is kind of up in the air.
Click to expand...

Be carefull there bucko! iWIREDhouses for 30 years before becoming an inspector!
 
Cavie said:
Be carefull there bucko! iWIREDhouses for 30 years before becoming an inspector!
Click to expand...

So what?

LOL

No offense, but that sounds like the 'ol "That's the way we always do it" reply

:D
 
The bigger problem is in the switch box. You can't use a normal nail on without running into box fill issues, you have to use something bigger with a P ring.
 
monkey said:
The bigger problem is in the switch box. You can't use a normal nail on without running into box fill issues, you have to use something bigger with a P ring.
Click to expand...

I just ditch the stack-switch that comes with the unit and install separate ordinary toggle switches for each load. Plenty of room in a 3- or 4-gang box!
 
iwire said:
I normally have 12/4 MC on board and if that where not enough conductors a length of 1/2" flex would would work fine.
Click to expand...
Now, there's an idea. :)

I can't imagine four - 12/2s entering those small JBs
Click to expand...
And I can't imagine running more than one grounded conductor if not needed.

infinity said:
We use 12/4 NM cable for these applications. One cable in the switch box and one in the fan.
Click to expand...
So how does the power get in? :confused: :grin:

kbsparky said:
We have 4-wire romex, but the problem here is you have 4 different switched loads and there ain't enough conductors present to do the job.

You need 4 hot conductors, and a neutral, plus a ground. ..:wink:
Click to expand...
Okay, so run a 12/2 and a 12/3, and color one of the whites blue.

480sparky said:
The only violation might be tying all the neutrals together in the fan unit. If you are running two neutrals in two cables, the loads on the read & black need to correspond with the neutral in the cable. 300.3(B)
Click to expand...
I wouldn't run more than a single neutral in this type of install, unless there was a heat load requiring a separate circuit, and then I'd look into making it a MWBC.

Whether I need two 12/2's or a 12/2 and a 12/3, I color one of the whites to use as an additional switched leg (re-coloring prohibition be damned).
 
Status
Not open for further replies.
Top