Adding a bathroom fan via dual rocker switch

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Old 08-15-16, 09:13 AM
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Adding a bathroom fan via dual rocker switch

Hey there,

So I'm in the process of adding a fan to a dual rocker switch but I'm getting lost somewhere in the wiring. I want the fan to operate on one switch and the light on the other.

My current Setup:
Receptacle has line coming in and load going to a switch to control the one light in the bathroom. The switch ONLY has the one line coming in from the receptacle. I'm not sure how the switch is actually wired to the light.

Since adding the fan, I have run the fan wiring directly to where the dual switch will be located. I also ran another 12-2 wire off the line side of the receptacle to the rocker switch (under the assumption that I would need power to operate the fan as I don't know how I'd wire the fan to the one load off the receptacle without that also powering the light...). I haven't actually wired the dual rocker switch b/c I want to be sure I'm doing this correctly.

I guess I'm not sure how my light switch was turning the light on/off if the switch is wired directly to a receptacle. It would obviously be easiest to just have one wire coming off the load of the receptacle going to the new switch box but like I said, my assumption would then be that both rocker switches would turn on the light...Thanks for the help.
 
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Old 08-15-16, 10:08 AM
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Not sure I completely understand your current setup, but here's a pretty good diagram of how it needs to be wired: Ceiling Fan Switch Wiring - Electrical 101

You would follow the diagram for the two switch setup, even though you are using a dual rocker switch it is wired the same as if it were two separate switches.

You will need three conductor cable from the fan/light to the switch.
 
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Old 08-15-16, 10:26 AM
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Thanks for the diagram...that makes sense. The only thing that I'm getting hung up on is that there doesn't appear to be wiring going directly to the light from switch (if that makes sense) - the wiring to the switch is just coming directly from the receptacle as far as I can tell.
 
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Old 08-15-16, 10:39 AM
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Tell us about all the wiring at the light. How many 3-conductor cables (black, red, white) if any and how many 2-conductor cables (black, white). Tell us the connections associated with each cable.
 
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Old 08-15-16, 10:43 AM
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I'll have to dig into that tonight and get back to you. I had only been looking at the outlet and switch...
 
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Old 08-15-16, 12:47 PM
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It sounds like you probably have a switch loop. One wire in the cable carries the hot from the outlet to the switch and the other wire in the cable carries the switched hot back to the outlet box, where presumably it is spliced to the cable going to the light.

If that's the case, you're going to have to run at least one new cable...
 
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Old 08-15-16, 01:45 PM
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Got it. I guess I'll try wiring it up how I have everything set and see what happens. If all else fails, I'm just going to wire them both to the one switch.
 
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Old 08-15-16, 07:54 PM
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UPDATE:

So, after messing around with the wiring for a while, I was able to get the light to switch on and off AND get the fan to run constantly - The only thing I'm missing here is getting the fan to switch off...Here is my setup:

Power into the receptacle and a 12-2 line off the load side of the receptacle directly into the top switch - this is how my light has always been switched there and it is working great.

I then have a second 12-2 wire coming off the outlet going to the switch - I have the neutral from this wire pig tailed with the neutral from the fan and then I have the hot from the fan going directly into the switch. At this point, the light turns on and off but the fan is constantly on and won't switch off. Any thoughts? How do I get the fan to switch off?

Thanks!
 
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Old 08-15-16, 08:31 PM
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How about giving us a picture of the switch showing all the wiring.

http://www.doityourself.com/forum/el...-pictures.html
 
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Old 08-15-16, 10:13 PM
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Here is the basic wiring for what you want to do.

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Can also be done this way but not best practice.

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Last edited by ray2047; 08-15-16 at 10:39 PM.
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Old 08-17-16, 09:29 AM
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I got it figured out! Thank you very much for all of the help. I ended up finding a diagram that I thought illustrated my circuit well:

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I then tweaked it like this to make it work:

DIAGRAM REMOVED BECAUSE IT WASN'T TO CODE AND I DON'T WANT TO BE RESPONSIBLE FOR SOMEONE ELSE USING IT (I tried to remove it - I guess it is hanging out below this though...)

-Tommy
 
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Last edited by Tommy Hjelmgren; 08-17-16 at 12:08 PM.
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Old 08-17-16, 10:28 AM
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The second diagram violates code because it switches the neutral. In the second both the light and receptacle are switched. The second diagram does not match your description "Receptacle has line coming in and load going to a switch". Your second diagram shows line in at the fan/light. Where does power (line) come in?
 
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Old 08-17-16, 10:35 AM
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I thought the power was coming through the light and going through the receptacle to the switch. I don't have a separate power line for the fan...

Is there any way to get the fan to switch on/off without me switching the neutral? Or would that require an additional wire to power the fan?

Thanks
 
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Old 08-17-16, 10:42 AM
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I thought the power was coming through the light and going through the receptacle to the switch.
That can only be determined by disconnecting each cable and measuring the voltage between black and white with a multimeter (or test light or solenoid tester). Have you done that? If not you need to. (Note: non contact testers won't work.)
 
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Old 08-17-16, 10:48 AM
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I will measure the voltage with a multimeter when I get home. Since I'm such an amateur at this I did want to throw out there that I personally put the fan in and I know there is no power running to the fan whatsoever as I ran the wiring for that directly to the switch. Additionally, I was up in my attic and saw that there was only one line running down to the receptacle; that line ran through the receptacle to the switch that powered the light.

Like I said, I'm a complete amateur at this...I have a digital multimeter so I will test voltage of the line running in at the switch and the outlet respectively.

If I wire the switch as the first diagram shows, would I be to code? Or, is that still technically switched? Thanks.
 

Last edited by Tommy Hjelmgren; 08-17-16 at 01:17 PM.
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Old 08-17-16, 05:07 PM
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Thank you for having me check voltages Ray! I found out I was most definitely wrong. I checked everything unconnected from any switch and/or outlet. So, I have a line coming into the outlet that showed 120v, and a line coming into the switch that showed 120v. That explains why my outlet worked even with my light switch off (duh!). I assume that means I have a power line to the outlet AND a power line to the switch.

The original wiring that I thought was bringing power into the outlet was actually sending power out to the hallway light. So...I still have the issue of what to hookup where.

If I focus only on the switch, I still have 2 sets of 12-2 coming into my lightswitch: One that has 120v and also powers the light and then another 12-2 coming directly from the fan (that is a separate unit from the light itself). I assume in this instance, I can ignore the outlet as it appears power is coming into that separately and that is also sending power to the hall light...

I also wanted to add that when the switch was operating the light only (prior to me putting in the fan), there was a black to one switch terminal and a white to the other...
 
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Old 08-17-16, 05:54 PM
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You need to break the tab between the switches and use them like to separate switches.

Is this a ceiling fan? Do you want both the fan and light controlled by a single switch or do you want the fan's light controlled by the wall switch and the fan motor by the fans pull chain switch?
 
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Old 08-17-16, 07:14 PM
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This is an exhaust fan in the bathroom, so it would just be on/off. I would just want one of the switches for the light and the other for the fan...
 
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Old 08-17-16, 07:45 PM
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12-2 coming directly from the fan (that is a separate unit from the light itself).
Sounds more like a switch loop then power in. How many cables at the fan? Is there two? Is one hot?
 
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Old 08-17-16, 08:23 PM
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The fan came with 3 wires (black, white & green) - instructions said add white to white, black to black, and green to green or bare copper - I did that and have that wire coming directly to the switch. The only wire at the switch itself (other than the one I just mentioned coming from the fan) is one 12-2 that holds the 120 volts.

Before I had the fan in - there was only that one wire at the switch (the one that holds the 120 volts) and that powered the light...I believe the black was connected to a terminal and the white was connected to a terminal at that point...
 
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Old 08-17-16, 09:13 PM
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If there is only one cable at the fan and it goes to the switch box. it is not 120 volts. It is power to the fan.
there was only that one wire at the switch (the one that holds the 120 volts) and that powered the light...I believe the black was connected to a terminal and the white was connected to a terminal at that point...
That would be a cable* not a wire. That would be a switch loop not a 120 volt feed. It would be most likely for the receptacle if the cable is really coming from it but more likely a switch loop not power from the light. From what you have written you have no power at the switch box. No way to power the fan.

What is the wiring at the receptacle? Is it really even involved? I don't see how.

Is this what you currently have at the switch box. If not explain how yours is different.

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*Terminology: Wires are single conductors. Cables are two or more wires in a metal or non metallic sheath. The terms are not interchangeable.
 

Last edited by ray2047; 08-18-16 at 02:06 AM.
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Old 08-18-16, 08:19 AM
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I know the fan doesn't have 120 volts - the fan is literally one cable that I attached and ran to the switch.

I believe your diagram is correct. After you had me check voltages, I believe that the receptacle is not involved and the light, as you say, is a switch loop.

As your diagram shows, I have a 12-2 cable coming from the fan to the switch - it is not wired to anything else whatsover - no voltage - it is just the wire directly from the fan.

At the switch itself, prior to putting the fan in, there was another 12-2 cable that was somehow turning the light on and off. When I checked voltages this cable at the switch had 120 volts. I believe that it did operate independently from the receptacle. With all this info and what you've been saying, I believe it is a switch loop for the light. Can't I add the fan into the loop?

If not can I run power from the receptacle to the fan? In that instance, how would it be wired to the switch? Would I break the tab?

Thanks for your help Ray - I appreciate it.
 

Last edited by Tommy Hjelmgren; 08-18-16 at 09:45 AM.
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Old 08-18-16, 09:25 AM
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For clarity's sake I wanted to just show that the cable for the light measured 120 volts; as you indicated and I also tried to explain, the fan has no voltage whatsoever - it is just the cable I attached to the fan:

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Old 08-18-16, 10:13 AM
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And if you open the light does it have two 2-conductor cables connected this way?

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Then the cable from the light is a switch loop not 120 volts. (You are just reading power through the light bulb.) You have no power for the fan.
 
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Old 08-18-16, 10:22 AM
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So if I check my light and it is wired as you show. How do I get power to the fan? Can I tap into the receptacle near the switch or would that then be looping through the receptacle which is a no-no?
 
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Old 08-18-16, 10:26 AM
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A quick test for the light would be to remove the bulb or bulbs. You should read ~0 at the switch box.
How do I get power to the fan? Can I tap into the receptacle near the switch
Yes.
 
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Old 08-18-16, 10:29 AM
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I will test it as soon as I get home.

So, if that is the case, I will tap into the receptacle and break the common tab on the switch, correct? Sorry, for all the questions...I would plan on wiring the light to the switch as it always was wired - would you happen to have a diagram for tapping into the receptacle for the fan? Thanks.
 
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Old 08-18-16, 10:32 AM
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I will tap into the receptacle and break the common tab on the switch, correct?
Yes.
I would plan on wiring the light to the switch as it always was wired
Yes. Give me a bit of time on the diagram.
 
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Old 08-18-16, 10:35 AM
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Seriously, thank you for putting up with me and all of the help. It's a difficult task trying to explain wiring but I'm sure it's even more difficult on the other end trying to understand what someone who has very little knowledge on the subject is trying to explain.

You are a life-saver!
 
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Old 08-18-16, 12:45 PM
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Here is the diagram. It assumes the exhaust fan does not require a GFCI receptacle and that the receptacle you are coming off for power is GFCI and has other receptacles connected. There are other combinations not covered by the diagram.

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Old 08-18-16, 01:49 PM
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No, this is perfect...Thank you very much for the help Ray.
 
 

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