Dimmer on a ceiling fan/light combo???

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Old 08-04-05, 04:52 AM
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Question Dimmer on a ceiling fan/light combo???

Hello:
I have a ceiling fan/light combo in my dining room that is controlled by one switch. I would like to be able to dim the 5 lights on the fixture. Can I put a dimmer as the switch control? I thought I had read somewhere that you should not use a dimmer on a fan motor. Since both the light and fan are controlled by one switch, the dimmer also would control the fan. Any suggestions? Thanks.
 
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Old 08-04-05, 05:03 AM
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Do not use a dimmer on the fan motor, unless it is designed for one. You MAY damage the fan motor. Contact the fan manufacturer for information on what they recommend.

You MAY be able to install a dimmer for the lights and use the pull chains for the fan, depending on how it is wired.
 
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Old 08-04-05, 05:04 AM
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If you put a dimmer switch controlling the fan, you will most likely hear a loud buzzing or humming sound from the fan motor. I believe the reason is that dimmers slightly change the frequency of the voltage and motors do not like this very much. One thing you can do if you really want to dim the lights and not affect the fan is to install a separate light switch that is dimmer controlled and then keep the fan on the existing switch.

Dave
 
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Old 08-04-05, 05:09 AM
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Follow up

If I were to re-wire it, I would only want to do that at the fixture (fan/light combo). Which wire controls the lights, and which wire control the fan motor. As I recall, blue is for the fan, but I am not sure. Thanks.
 
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Old 08-04-05, 05:25 AM
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If you have a switch loop, you can probably take the fan down and rewire things so the fan is controlled by the pull chains only and the light is controlled by the switch. You can then replace the switch with a dimmer (make sure the dimmer does not need a neutral).

To see if its a switch loop, examine the box that the switch is in. If there's only ONE cable, and its white and black wires both connect to the switch, you have a switch loop.

In that case, take the fan down. Determine which black wire is the incoming power (if done right, it will have a white wire nutted to it, but this is dependant on how the install was done). Connect the incoming power black to fan black. Then connect the switched power black to fan blue (or black/white stripped). Finally, connect the incoming power white to fan white.

Even if I didn't want a dimmer, I'd do this so my fan stays on when the light is turned off.
 
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Old 08-04-05, 07:38 AM
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You can probably use a Hunter All-Fan to get what you want without any changes to the wiring in the wall. It comes in two flavors, one with a hand-held remote and one with a wall-mounted controller.
 
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Old 08-04-05, 08:04 AM
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to chirkware (posted correctly this time)

The last time I tried to post this, my comments were inside the quote box of your reply. I have cut and pasted my comments in this post. Sorry for the screw up!

Thanks for the reply, but, for my own information, what is the reason for the white wire in the switch loop to be used as the supply hot? Is there some reason for this, or is it simply convention for electricians to do it that way?

Also, will these new connections be in the ceiling box, or in the bell at the bottom of the fan motor, where the wires feed to the individual lights?

Thanks

Originally Posted by chirkware
If you have a switch loop, you can probably take the fan down and rewire things so the fan is controlled by the pull chains only and the light is controlled by the switch. You can then replace the switch with a dimmer (make sure the dimmer does not need a neutral).

To see if its a switch loop, examine the box that the switch is in. If there's only ONE cable, and its white and black wires both connect to the switch, you have a switch loop.

In that case, take the fan down. Determine which black wire is the incoming power (if done right, it will have a white wire nutted to it, but this is dependant on how the install was done). Connect the incoming power black to fan black. Then connect the switched power black to fan blue (or black/white stripped). Finally, connect the incoming power white to fan white.


Even if I didn't want a dimmer, I'd do this so my fan stays on when the light is turned off.
 
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Old 08-04-05, 09:34 AM
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Originally Posted by JMattero
Thanks for the reply, but, for my own information, what is the reason for the white wire in the switch loop to be used as the supply hot? Is there some reason for this, or is it simply convention for electricians to do it that way?
It is actually a code requirement for a switch loop. In a switch loop, there is generally a 2-wire (plus ground) cable ran from the fixture box to the switch box. The white wire carries the current to the switch. The black wire then returns the current to the fixture when the switch is on. The white wire is also required to be "reidentified" as hot in some way. The most common methods are wrapping black electrical tape around the wire and coloring the wire black with a permanent marker.

Note that just because that is code does not neccesarily mean it is what you will find when you open up that box. Unfortunately, many installations don't meet code. I'm not sure how long code has required using the white to carry current to the switch, nor do I know how old your house is, so it may not have been a code requirement at the time your home was built.

Common sense says having the black as the switched hot is logical. If the white wire was the switched hot, that would leave the person installing the fixture with two white wires hanging out of the ceiling. They would need to determine which was hot and which was the neutral. By this code requirement, you are left with one black and one white hanging out of the ceiling, and nothing to have to figure out.


Originally Posted by JMattero
Also, will these new connections be in the ceiling box, or in the bell at the bottom of the fan motor, where the wires feed to the individual lights?

Unfortunately, they will be at the ceiling box, so the entire fan has to come down at least part of the way. You may find it easier to take it all the way down if the wires in the box are hard to get to. Of course, if you think you'll ever want a different ceiling fan at this location, now would be the time to change it!

BTW: Have you confirmed whether you have a switch loop? If not, there's no point in taking the fan down unless you can run a new cable from the switch to the ceiling box. See my previous post for determining that. You can tell at the switch. Be sure to shut off the breaker before sticking any fingers in there!
 
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