DIY Home Improvement Forum banner

1 - 20 of 22 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
I have a question here. I pulled out an old exhaust fan/heat lamp combo unit from the bathroom ceiling. I want to install a fan/light combo. All the ducting work is easy enough, but the old unit was 220 and the new is 110. I know the red and black are both hot, white is neutral, ground is ground, etc. Can I use the black to run the light and the red to run the fan, and pigtail the white to cover both? Running new wiring is not an option, unless I want to trench the walls, and I don't want to. So my basic question is, can a 220 be split into two 110 lines?
 

·
Household Handyman
Joined
·
2,480 Posts
Are you sure the old unit was 220v ? It's just that I have never seen a light/fan unit that was 220v, but it could be. Could it be that you had a light/fan unit that had the light fed from one 110v breaker in the panel and on one switch say with the red wire, and the fan fed from a different 110v breaker in the panel and on a separate switch say with the black wire and they were on separate breakers and bus bars in the panel, and they shared a common neutral and ground, therefore when you checked the red/black wires you would be reading 220 volts. I believe I would double check all the way back to the panel, and check for any labels on the old light/fan unit for the voltage on this one. I've wired light/fan combos this way so they would each be on their own respective switch and fed from opposite bus bars, yet each application (light/fan) would only be 110 volt. Good Luck, David
 

·
DIY'r
Joined
·
520 Posts
Could it be that you had a light/fan unit that had the light fed from one 110v breaker in the panel and on one switch say with the red wire, and the fan fed from a different 110v breaker in the panel and on a separate switch say with the black wire
Agreed, good chance Thurman is right. Definitely verify this before wiring up the new fixture.

Or, just use one circuit. If the new fixture isn't a heat lamp, it isn't going to draw much.

Actually, by sharing the neutral, you're creating a multiwire branch circuit, so you'd want to keep it on the double-pole breaker.
:thumbup: Though if it was indeed a 240V fixture it would already be on a double pole breaker (or hopefully so).

Yes I agree if your going to use a GFCI or an Arch fault breaker.
Has nothing to do with AFCI or GFCI. A MWBC should be on a double-pole breaker. It is required under the 2008 NEC, and is just a good idea anyhow.
 

·
UAW SKILLED TRADES
Joined
·
5,341 Posts
Thurman......It wasn't a fan and light ....it was a fan and heat.

If the 120/240 volt circuit only supplied the old fan/ heat lamp which would almost be certain, i'm not sure why you would want to have a double pole breaker involved to supply a 120 volt light/ fan combo. Your talking less than 5 amps total.

From the sound of it you have a 3 conductor cable coming from the panel to a switchbox in the bath, something like 12/3G NM-b would be common. Simply use one single pole breaker and abandon one hot wire (cap it at the panel and at the switch box) and use the neutral and ground as is.

At the switchbox your 3 conductor cable should continue to the fixture. At the switchbox use both hot wires in the cable going to the fixture and two single pole switches or a combo switch (2 switches on a single yoke). Connect the constant hot from the breaker to the combo switch or use pigtails if two switches. Leave the neutral alone and connect all grounds properly. Connect the two switchleg hots to the switches or combo switch.

Something like this.....
 

Attachments

·
Registered
Joined
·
1,758 Posts
I have a question here. I pulled out an old exhaust fan/heat lamp combo unit from the bathroom ceiling. I want to install a fan/light combo. All the ducting work is easy enough, but the old unit was 220 and the new is 110. I know the red and black are both hot, white is neutral, ground is ground, etc. Can I use the black to run the light and the red to run the fan, and pigtail the white to cover both? Running new wiring is not an option, unless I want to trench the walls, and I don't want to. So my basic question is, can a 220 be split into two 110 lines?
Are the fan and heat lamp separately switched? It is highly unlikely that this is a 220V circuit. Take a meter, put one lead on the red, one on the black. Select "AC Voltage." If it reads 240V then it is a 240V. Any other reading and it isn't. Probably, it's 120V and split somewhere and run to the heat lamp/fan. 120V is all there is, but somewhere a red and black is connected to a black, and then each goes through a separate switch and on to the fan or lamp. The neutral serves both, and since the total amperage is going through the same breaker, there is no problem with overloading the neutral. This is the way a ceiling fan with a light is wired. 12-2 come in, gets split with 12-3, and runs to the fan/light through separate switches using only one neutral.
 

·
Household Handyman
Joined
·
2,480 Posts
Stubbie-you may kick my buttocks, just once. I did over read that one. Forgive my 60 year old bifocaled eyes, please. :eek: But, I thought I had a good idea. OH, Stubs, I'm retired GM/UAW skill trades. :thumbup:
 

·
UAW SKILLED TRADES
Joined
·
5,341 Posts
I will agree that this very well may be a 120 volt circuit ( I made the assumption OP new what 240 volts was.....:)) There are a few 120/240 volt fan/heat lamp combinations out there but newer and many older units are almost always 120 volt and around 12 amps.

Regardless... the diagram is accurate though he may not have the 3 conductor from panel to switchbox. But I think he can figure it out. A few more questions probably should have been asked for clarification. Looks like they have been asked so lets see what he has....l
 

·
UAW SKILLED TRADES
Joined
·
5,341 Posts
Stubbie-you may kick my buttocks, just once. I did over read that one. Forgive my 60 year old bifocaled eyes, please. :eek: But, I thought I had a good idea. OH, Stubs, I'm retired GM/UAW skill trades. :thumbup:

Actually I think you're going to end up correct in that it is 120 volts.....:)
 

·
Registered
Joined
·
5 Posts
Discussion Starter #14
Ok, after completely dismantling everything, it turns out it's a 220 wire running as 110. The red wire is not hot and just coiled up behind the switches. Forgive me if my explanations are not proper, but I'm a tilesetter trying to help a friend with some wiring. Anyway, if I ignore the red wire altogether, what kind of breaker should it be on? Maybe it's been fine all this time, but I'm going to make sure it's proper. Tomorrow I will trace the wire back to the panel and see if it's a double or single pole, and what amperage it's rated for. Can someone tell me what I want it to be? Thanks.
 

·
Registered
Joined
·
44 Posts
I would think a 20 amp single pole breaker would be more than enough if it's a dedicated circuit. Someone please double check me though because I don't have a lot of experience with fan/light combo's.
 

·
Registered
Joined
·
86 Posts
Ok, after completely dismantling everything, it turns out it's a 220 wire running as 110. The red wire is not hot and just coiled up behind the switches.
Was the old unit controlled by one switch, or two?

If it was only on one switch, congratulations, you just found out you have a spare wire run so that you can convert from a single switch to two (or a combination switch).

If it was already on two switches, just leave the red wire capped on both ends, and hook the old fan switch to the new fan, and the old heat lamp switch to the new light.

No need to trace back to the panel.
 

·
UAW SKILLED TRADES
Joined
·
5,341 Posts
Ok, after completely dismantling everything, it turns out it's a 220 wire running as 110. The red wire is not hot and just coiled up behind the switches. Forgive me if my explanations are not proper, but I'm a tilesetter trying to help a friend with some wiring. Anyway, if I ignore the red wire altogether, what kind of breaker should it be on? Maybe it's been fine all this time, but I'm going to make sure it's proper. Tomorrow I will trace the wire back to the panel and see if it's a double or single pole, and what amperage it's rated for. Can someone tell me what I want it to be? Thanks.
You are saying switches as in two individual switches?

Did one switch control the fan and the other the heat lamp?

I am assuming from your first post that a red wire was in the fixture box and connected to a fixture wire...either the fan or the lamp. If so that red wire should be in the switch box connected to a switch.

Please explain what wires are on the switches....refer to the diagram I posted.


If there is a RED wire that is unused it likely is exactly like the diagram unless the only red in the switch box is the red going to the fan/light location. Please clarify if there is more than one red wire and is a red wire connected to a switch.

My guess is you likely don't have to do anything except install your new fan/light. Use the red for the light and the black for the fan and connect all neutrals in the fixture box.

You might have 14 awg or 12awg . If 14 awg wire use a 15 amp single pole breaker..... if 12 awg use a 20 amp single pole breaker.
 

·
DIY'r
Joined
·
520 Posts
I would think a 20 amp single pole breaker would be more than enough if it's a dedicated circuit. Someone please double check me though because I don't have a lot of experience with fan/light combo's.
Atroxx, regardless of the fixture involved, the breaker's rating would depend upon the lowest gauge of wire in the circuit.

You might have 14 awg or 12awg . If 14 awg wire use a 15 amp single pole breaker..... if 12 awg use a 20 amp single pole breaker.
.. Just wanted to add that if you're not sure what else may be on the circuit, a 15A breaker is the safe bet. Even if you have 12 awg wire @ the fixture and switch it doesn't necessarily mean it's 12 awg on the entire circuit.
 
1 - 20 of 22 Posts
Top