Dimmer switch for ceiling fan??

[lithnights]

The house we bought has a family room that controls two ceiling fans with a dimmer switch. Is this normal? It doesn't appear the setup works too well and although the speed seems to change a bit (but hums on anything other than fully on or off) you certainly can't control the speed of the fan from Low, Medium, High like you could with the chain. I can see what they were thinking b/c the fans are on a high cathedral ceiling and are impossible to get to the chain without a ladder.
Also, our bedroom has a single dimmer switch that connects to a light/fan combo. The dimmer switch turns the fan either on or off but can dim the light. But when the light is dimmed and the fan is on, the fan hums like crazy unless the light is fully on or off. I know I can rewire the setup to avoid this but I wonder, should fans be controlled with a dimmer?

[LazyPup]

Absolutely not,,light dimmer controls work by reducing the line voltage.

Electic motors require full voltage on the windings at all times. Reducing the voltage will result in increase amperage draw and excessive heat build up in the windings, end result, the motor will burn out prematurely.

Most multi-speed motors found in residential applications have internal taps on the motor windings to change the speed. In a sense, if it is to run the motor at half speed there is a tap on the center of the winding so it only uses 1/2 of the winding, etc, etc, but in all cases, the energized portion of the winding must be at full voltage.

There is another method of altering motor speed by changing the frequency of the supply current. While normal residential AC is at 60 hz, there are special controllers that can increase or decrease the frequency to change motor speeds, but they are very expensive and normally only found on high end commercial applications. Frequency controllers will not work on all types of motors either.

With some rare exceptions, If you desire to have a ceiling fan with a dimmer on the lights it requires a three wire cable from the switch mount position to the ceiling fan unit, with separate switches for fan and lights.

Operating a motor through a dimmer control is potentially a serious fire hazard and should never be done.

[HayZee518]

LUTRON is a controller made just for ceiling fans. Conventional lighting dimmers will not work! LIGHTOLIER has a remote unit that works with ceiling fans but you need access to the canopy of the fan to install it.