Speed control of ceiling fan

pjpjpjpj · 03-18-2007, 05:25 PM

I know there are plenty of ceiling fans out there that have speed control using a rheostat ("dimmer"). But I have a question about "doing it myself".

I have a typical cheap three-speed (with the pull-chain; hi-med-lo-off) ceiling fan. It has a light fixture that can be wired separately from the fan power. My question is, could I wire the fan power (only, NOT the light too) to a rheostat (rotary or slide "dimmer switch"), set the pull-chain to "high", and then just effectively run the fan with the dimmer? I realize that the fan is probably not "intended" to be controlled this way, but if it is a multi-speed fan anyway, then the motor is obviously variable-speed, right? As long as I have the pull-chain set to "high", then I would expect the "dimmer" would control the fan speed from that high setting down to "off".

Does this sound correct? Any reason why it would not work? I feel like I have seen this suggested (or "optional") in fan installation brochures, but I no longer have the brochure for the fan I have.

AndrewH · 03-18-2007, 05:33 PM

yes, it will work but you have to use a controller rated for a "motor load". They are availible at hardware stores or electrical supply houses and are made by the same companies as dimmers so are styled the same. Make sure the feeds for the light and fan are seperated and the pull chain is set for high.

Speedy Petey · 03-18-2007, 05:35 PM

What Andrew said.

Yes, it is "intended" to run that way. The fan switch stays on high and the wall speed control slows the fan down.

You keep referring to a "dimmer". Fans are NOT to be controlled by a light dimmer.

pjpjpjpj · 03-18-2007, 05:54 PM

Thanks for the help, guys. I have a spare light dimmer (the kind with a narrower switch and small slider that fits in a standard wall plate) that I was going to use for this application, but I won't per your advice!

Just for my knowledge, is this because of startup amp surge or something? The fan motor should be within the operating amperage of the dimmer. Or is it just a UL rating thing (meaning it "could" work but is not rated to)?

AndrewH · 03-18-2007, 09:57 PM

I have seen older rheostat type dimmers used as motor controls (in paddle fans) with no visible problems, but todays dimmers are mostly electronic and the components are only rated for its intended loads. Usually an immediate failure of the components occurs when you deviate from the mfg. specs. I have never seen one catch on fire but I have had to carve out the melted remains of improperly installed dimmers.

mikemy6 · 03-19-2007, 11:17 AM

There are remote units that are cheap and easy to install on any fan or fan light combo. Ive used them and would recomend them. im just not sure if this is what your going for here.

pjpjpjpj · 03-19-2007, 12:20 PM

Thanks again for the advice. I found several online at the Lowe's/HD -type places. Not too expensive at all. It appears that they only do the three-speed thing though, not a "true" rheostat operation, but whatever. The typical use is for vaulted ceilings where you can't reach the pull-chain, so you just have the three-speed controller on the wall.

I have 8-foot ceilings (easy to reach the chain), but I was going to put one on the wall in the baby's nursery so I wouldn't have to enter the room (and risk waking the baby) if I wanted to change speeds on the fan or turn it on/off. That way I can just peek in, reach in and flick the switch.

Speedy Petey · 03-19-2007, 04:13 PM

Bear in mind. ANY full variable speed control will contribute to, and even cause, fan hum.
The 3-speed controls from reputable manufacturers are your best bet for a quiet fan.