Dimming a fan
- Thread starter Geon_W
- Start date
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- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Depends on the fan motor used. If it is a Shaded Pole motor, then yes, an old fashioned rheostat can work (but good luck finding one). If it is a motor with a capacitor (Capacitor-Start, Split-Phase etc.) where there is a centrifugal starting switch, then no, you cannot control the speed in any way. If it is a PSC (Permanent Split Capacitor), then you can use a true 1 phase VFD, but that is much more expensive.
Thanks, wikipedia says otherwise.
"A shaded pole motor...... These motors have only one winding, no capacitor nor starting switch,..... Moreover, they are compatible with triac-based variable-speed controls, which often are used with fans......"
http://en.wikipedia.org/wiki/Shaded-pole_motor
"A shaded pole motor...... These motors have only one winding, no capacitor nor starting switch,..... Moreover, they are compatible with triac-based variable-speed controls, which often are used with fans......"
http://en.wikipedia.org/wiki/Shaded-pole_motor
billsnuff
Senior Member
- Location
- East of 480sparky
I'll take jraef and 480 sparky OVER W-pedia any day............
roger3829
Senior Member
- Location
- Torrington, CT
Geon_W said:
No.
See 110.3(B)
Why would you want to??
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Geon_W said:
If you use a variable speed dimmer made for fans I will bet that you will get humming from the fan. I suspect you will also have the same problem from a standard dimmer.
Of course, the type of fan comes into play here. The old Hunter paddle fans could not be used with a 3 or 4 speed dimmer but had to be used with a variable speed control. They always hummed.
The fan specs as listed by the manufacturer are as follows.
120V,
0.24A,
20W,
RPM 3100
MOTOR TYPE: shaded pole
I've tried a 3 speed control, below are the results
lowest speed - fan stayed off
middle speed- fan ON
High speed - fan on, no increase in speed.
I now want to attempt a fully variable control, before I spent my time and money I want to know what to expext
120V,
0.24A,
20W,
RPM 3100
MOTOR TYPE: shaded pole
I've tried a 3 speed control, below are the results
lowest speed - fan stayed off
middle speed- fan ON
High speed - fan on, no increase in speed.
I now want to attempt a fully variable control, before I spent my time and money I want to know what to expext
Last edited:
Geon_W said:
Sounds like something isn't wired right, or its a bad fan. Why not just return it and get another one?
If you really want a speed control, look online at Hunter fans and Casablanca fans. They make speed controls made for fans.
Steve
electricmanscott
Senior Member
- Location
- Boston, MA
Sounds to me like the speed switch on the fan itself was not set on high.
Maybe you should have an electrician take a look at this.
Maybe you should have an electrician take a look at this.
electricalperson
Senior Member
- Location
- massachusetts
most new fans ive installed recently come with a controller and a remote control that allows dimming of the light kit. does the fan company offer one of these kits for your fan?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Geon_W said:
I would contact the manufacturer of th motor and find out what they require for their equipment.
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