VFD on Ceiling Fan

[chancellor]

I have been given the task of finding a way to control the speed of ceiling fans based on outside air temperature. I have located relatively inexpensive Variable Frequency Drives which were developed for use with ceiling fans; however i am unable to find ceiling fan manufacturers with inverter duty rated motors in their product. The VFD manufacturer claims that their VFD will work with fan motors that are Permanent Split Capacitor motors. Will i encounter problems (motor life, noise, etc.) with a VFD driving this type of motor(permanent split capacitor)?

 

[stanlsimon]

The typical speed controller for ceiling fans is a simple knob on the wall that turns the amperage down by clipping the topsand bottoms off the sine wave. Not really a VFD but it works.

The application you are describing is way more advanced. Maybe one of the larger industrial ceiling fan manufacturers has a motor with the insulation on the windings rated for inverter duty.

One thing that might help is to put reactors in series with the motor to suppress any voltage spikes.

Talk to a sales engineer at SmartFan, they have control packages that might do what what you want with simple phase clipping.

 

[quark]

Biosafety Cabinet manufacturers use microprocessor based speed control for fans, controlled by velocity of the flow stream, without using a variable frequency drive.
Electrical forum237 can be of help to you regarding details.

 

[Joesteam]

I have used a product for air intake in a boiler room that uses a VFD fan unit. May not be the least expensive option, but look at Exhausto

http://www.exhausto.com/composite-11.htm