Hi, This sounds dumb but when NM is used as a wiring method what do you run to a bath fan that has fan,light, heat and night light? This would require 5 wires (4 hots and a neutral.) I had installed 12/4 romex (white,red,black and blue) not knowing it had a night light. Do I remove the 12/4 and install a 12/3 and 12/2 and use one of the whites as a hot and cut the other off? Thanks for any ideas
bath fan
- Thread starter elecmen
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
The unit is meant to be wired to one circuit so why separate. Also 14/2 and 12/2 will not work if you need 4 hots and a neutral. Remember, in your scenario you need a neutral in both runs. So if you ran the 12/2 for the heater then you still need a neutral and 3 switch leg-- there is a night light in it.
To the OP I usually never wire up the night light unless the homeowner wants it but you can run 2- 12/3 cables and separate the neutrals appropriately.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
First never cut any wires.
Second don't you have an installation guide?
PP 3 of this: http://www.broan.com/ImageLibrary/broan/pdf/InstallGuides/99043764.pdf
gives you an idea how to do it.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
You can run a piece of carflex, greenfield etc and run what you need otherwise run 2- 12/3 NM cables.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Does anyone see the problem with the broan wiring diagram in the above PDF if the heat/night light is fed from a different circuit then the fan/normal lights?
Hint look at the temperature switch that turns on the fan in heat mode
Hint look at the temperature switch that turns on the fan in heat mode
I guess what I'm not getting through my head is why you need 2 neutrals if every things on the same circuit. In your suggestion of 2 12/3's both whites would be used for neutrals? Say 1 for light anf fan and one for heater and nite lite?
jetlag
Senior Member
- Location
- Eatonton, Georgia
I seems you already have hot and neutral in the switch box , leave the 12/4 ,its already in . Just run another 12/2 to the night light , and break the hot before it leaves the switch , connect the neutral in the switch box but only connect it to the night light in the fan box . :grin:
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
There is also a nite light. Fan/light/heat/nite light. If you run 2 cables then the neutral must be run in the cable except for a few exceptions. 300.3(B)-- this is why you should have a neutral in each cable. If you run nm cable, it is not necessary to run the neutral in both cables however it will create emf's.
jetlag
Senior Member
- Location
- Eatonton, Georgia
You dont have to have 2 neutrals , it will work fine with all neutrals together in the fan box and that is allowed with romex, but you are learning the finer points of wiring, it is best to keep a seperate neutral in each cable when ever possible for reasons as stated by dennis :grin:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I'd run a 12-2 and a 12-3, keep both cables together from switch box to fan J-box, and re-color one of the whites blue at both ends.
- Occupation
- Licensed Electrician
That's me too.
If I did hook up the night light it would be like this.^^
ptonsparky
Tom
- Occupation
- EC - retired
Don't forget the rubber coated hammer handle to cram all those solid wires in a box to small for the wire connectors. We use a piece of flex with stranded wire.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Does anyone see the problem with the broan wiring diagram in the above PDF if the heat/night light is fed from a different circuit then the fan/normal lights?
Hint look at the temperature switch that turns on the fan in heat mode
I only saw one feed. Did I miss something?
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
yea, the "what if"
It is very common to feed the lights and fan from the bathroom lighting circuit, and run a separate 15 or 20 amp circuit for the heat, if you notice the two feed points in the broan are neutral paired as heat/night light, and fan/main lights, if this fan gets fed from two circuits such as the fan/main lights from the existing bath light circuit, and heat/night light from a new 15/20 amp circuit, the thermal cut in switch that brings on the fan in heat mode will bond these two circuits together if the switch for the fan is also on at the time.
older heat fan units and or other brands are not paired like this, so some installers might just not look for this when wiring, as evidence in this thread in post 3 and 5
The PDF just shows an example of how the circuits can be wired, it doesn't say it has to be wired that way.
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jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
No I do not see two 'feeds'(seperate circuits). This fan can not be run off the bathroom circuit.
I am still missing your point. Sorry sometimes I am slow.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Don't worry, as I'm not the best at explaining what's in my mind lately
But I'll try, in the J-box on the fan is two neutrals, one is solid white, the other is a white with a red stripe, on the switch is two hots, the upper portion (3-position rocker SPDT) is a black hot pigtail along with a red and blue pigtail, on the bottom section of the same switch is one screw for a hot, and two screws for the fan and heat loads, so you have two hots on the same switch and two neutrals at the fan box, this is many times miss took to mean that this fan can be fed by more then one circuit, I agree we should be reading the instructions when we install them, and I also agree that putting this fan on more then one circuit would violate code, as it is clear if fed from two circuits the neutrals will not be paired with the correct hots, and the fact the thermostat cut in for the fan will connect the two circuits, but like I said not all fans are wired like this, and it was common to use a new separate circuit for the heat portion of the load.
SO yes I agree this model Broan should not be wire to separate circuits.
I was just trying to point out why.
an older version Broan (before Newtone bought out Broan) had the fan together with the heat sharing the white/red neutral, and the night light with the main lights sharing the white neutral, which had no problems with being fed from two circuits.
Also the older Broans didn't always come with the special switch, you had to get one from the suppler or use separate single pole switches.
the first time I saw the way these new Newtone/Broans are wired I thought to myself how goofy can you get.:roll:
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