fans on dimmers?

[Steve]

hi, is it possible to control a fan such as this one:

http://www.tlc-direct.co.uk/Products/EN78376.html

using a standard dimmer switch in a 2-way configuration (switch and dimmer)? I know about AC and dimmers that chop waveforms etc, just wondered if it would be possible or whether the fan needs full AC waveforms all the time. I know this fan comes with its own controller, but a ordinary dimmer would look better im sure, than a seperate module.

 

[breezer]

as you said

I know this fan comes with its own controller

says it all really

 

[mapj1]

It depends on the type of motor - brushed motors can normaly be "dimmed" in the triac way, but there may be a need for further spike supression than normal. Capacitor run motors that are near synchronous may or may not be OK, and may only start at full power. The only way to be sure is to try, and be prepared to say good night to the dimmer if it objects to the load.

 

[felix]

Some fan speed control boxes simply switch capacitors in series with the fan motor. An induction motor can be run on reduced voltage and at reduced speed if it is designed for this. One way of doing it is to put extra resistance into the rotor, something you can easily do if the rotor is on the outside.

Will it work on a dimmer? The motor probably will but the dimmer might not like inductive loads. Check your fan control box first to see what's in it. If you find only switched capacitors in there give the dimmer a go. You might be lucky.

 

[Steve]

Thanks for the advice. I have found a fan controller that looks just like a dimmer, with a picture of a fan on it. Purpose made, so there shouldnt be a problem i hope! I have scaled down my plans too, i only need to control it from one point, so no need for a 2-way controller. Cheers!