# Wiring a ceiling fan with wall switch (electrical question) **URL:** \ **Category:** Factual Questions\ **Created:** [June 28, 2004, 2:30am UTC](https://boards.straightdope.com/t/wiring-a-ceiling-fan-with-wall-switch-electrical-question/252480 "2004-06-28T02:30:14Z")\ **Posts on this page:** 3\ **Page:** 2
**Author:** ![BoringDad](https://avatars.discourse-cdn.com/v4/letter/b/ad7895/32.png) [@BoringDad](https://boards.straightdope.com/u/BoringDad)\ **Post date:** [June 29, 2004, 5:54pm UTC](https://boards.straightdope.com/t/wiring-a-ceiling-fan-with-wall-switch-electrical-question/252480/21 "2004-06-29T17:54:40Z")
> [@theR](#): > > Ok, it’s working now. I put the wires back to the original configuration and took special care that the wires weren’t touching each other or anything else. I’m still pretty sure the red wire wasn’t touching another wire, but maybe it was touching the metal outlet box before after I capped the wires and tucked them in? That would certainly produce the results you described, if by red wire touching you meant bare copper from the red wire. There should be no bare copper exposed out of the wire nuts on any of the wires. If it was the insulation on the red wire touching the box, you may have a bad spot in the insulation that needs repaired/replaced. This is a very bad thing. ---
**Author:** ![Omphaloskeptic](https://avatars.discourse-cdn.com/v4/letter/o/bcef8e/32.png) [@Omphaloskeptic](https://boards.straightdope.com/u/Omphaloskeptic)\ **Post date:** [June 30, 2004, 12:10am UTC](https://boards.straightdope.com/t/wiring-a-ceiling-fan-with-wall-switch-electrical-question/252480/22 "2004-06-30T00:10:53Z")
> [@Balthisar](#): > > There’s a single, three strand Romex to the fan. One black (hot), one white (neutral), and one bare (ground). Makes sense – there was probably “just” a light here when the house was built, and the construction company was too cheap to run a different type of Romex. > > Here’s the nutty part: the switch consists of a dimmer for the fan light and a “dimmer” for the fan speed. They both work _independantly_. > > The ground really is a ground – they didn’t do anything fishy with the bare wire. > > So anyone care to explain to me how the hell this works? I can think of a few ways for this to work, but they all involve nonstandard “dimmer” switches (or using the third wire as a third current-carrying wire, which doesn’t seem to be the case). One way, like **ZenBeam** says, is to have the switch merely send a signal (either wireless RF or modulated on the wires, X10-style) to the fan, which has its own power switching circuitry. Another way would be to have the light’s dimmer adjust the DC bias of the hot wire and the fan’s dimmer control the AC amplitude. At the fan a filter could split these frequency components (an explicit filter may not even be necessary, if the fan motor has low DC resistance). Similarly, the dimmers could be separately controlling the positive and negative halves of the cycle, but this would lead to more noticeable flicker in the light; I don’t know if it would be bad for the motor. Can you describe the wiring at the switches? Presumably you have three wires coming into the switches from the main house wiring (hot, neutral, ground). Which of these wires are connected to which switch, and which of the three wires from the ceiling fan are connected to which switch? Do the dimmer switches appear normal? (For that matter, do they work at dimming a normal lightbulb?) ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [June 30, 2004, 12:49am UTC](https://boards.straightdope.com/t/wiring-a-ceiling-fan-with-wall-switch-electrical-question/252480/23 "2004-06-30T00:49:20Z")
Doh! I installed X10 all over my previous house – including the fan! And know exactly how it works. This sounds like it’s a perfectly good explanation. No, I’m honestly not whoosing anyone. It was driving me crazy for the impossibility factor, too. Don’t know how the switch is wired – yet. It’s actually kind of bad news, because I was planning on replacing the ugly, rotary switches with a set of attractive, slider switches. If it’s a custom job, I’m outta luck. A quick Google search reveals that the manufacturer probably doesn’t exist. Virtually no references to it. Ah… but another search reveals fans/lights that have remote controls a la X10, so, yeah, there’s the precedent – some fans have on-board electronics – thyristors like X10 for the lights, I imagine, and whatever they use for inductive loads (hmm… what would they use? I had to buy a special X10 controller for my previous fan, specially for inductive loads. Not a relay, but a “dimmer”). [Previous page](https://boards.straightdope.com/t/wiring-a-ceiling-fan-with-wall-switch-electrical-question/252480.md?page=1)