Old AC Motor varispeed, possible?

[boatelectric]

Old homes heatilator has a fan assembly that is welded to it. The homeowner would like to either vari the speed or step it (low, med, high) but everything I have tried is giving me the same results. I suggested we replace the motor with one that is able to do what is wanted but the assembly is welded to the system.
The motor is a Dayton Electric E37403, rpm- 3160, 115 vac, 1.37 amps, 1.25 hp, type U21, No. 7021-3469 continuous duty, model 4C446 Thermally protected CA82, Class A ins.
The motor is in excellent shape, just not able to vari the speed. Is this motor capable and if so, what type of a controller can be used?
Thank you

 

[rbulsara]

1.25 HP , 115V motor will draw 7 amps or more.
Check and repost your current /HP rating.

A fan regulator type control should work, if meets the current rating.

Plus what exaclty have you tried so far?

 

[boatelectric]

I double checked what is written on the side of the motor and what I posted on the site. The information that I posted is correct, according to the tag on the motor.
I have tried a variable and a 3-speed ceiling fan switch, both rated at 5.0 amps.
With both the variable and the 3-speed switch I was not able to control the motor. I can set the fan at full speed and I can set the fan at a low speed, nothing in between. When I sit and tweak the speed of the motor, very carefully. It eventually just runs away and goes to full speed.

 

[rbulsara]

Your motor nameplate is a suspect.

Motor speed is not directly related to V.

In fact its only dependent on frequency and poles which remains constant. Resistive regulators for small ac motors essentially drop voltage down and limit the current (much energy is lost in heat)that the motor is bogged down, hence slows down.

It appears that your motor is lightly loaded and regulator characteristic do not match the motor to give you the desired speed control.

I am not sure single phase inverters, VFD, are available or even its cost will be justified for your application.

I am not initimately faimiliar with electronic fan regulator construction or theory..so will wait for someone else knowing it to respond.

 

[jbartos]

Suggestion: Visit

http://www.electricmotorwarehouse.com/

for Dayton motors more info
and also bring it to a motor repair shop to find where the problem is since the nameplate information is inconsistent.

 

[jOmega]

If y'all want to see the data on that motor....

you'll find it here:

http://kingsolar.com/catalog/mfg/dayton/4c446.html

It's a Shaded Pole motor, 1.37 amps ...

NO HP LISTED for this motor... so Skieve posting of 1.25 HP might be erroneous...could it be 1.25 SF ???

MFGRs Data
No. 4C446 Shaded Pole Blowers - 148 CFM at RPM shown at 60Hz and 0inches SP, 1.37 Amps, 115 volts


Now, for a variable speed solution,
might I suggest that you investigate Anacon Systems, Inc

http://www.anaconsystems.com/text/singleov.html

who makes a variable speed controller for 1-phase, 115 vac, shaded pole motors and PSC motors.

HTH
jO

 

[boatelectric]

Thank you very much guys.
I will dig around at the links I was given and see what I can come up with.
Thanks again,
Steve

 

[imok2]

Steve, I installed a small fan like yours in my hearth for the fire place and I used a simple adjustable reostat to adjust the proportional motor speed, it works fine.

 

[imok2]

Steve If you don't like my first post...try this

http://www.hoffmancontrols.com/variflow.htm

 

[jbartos]

Suggestion to Skieve (Electrical) Nov 7, 2003 marked ///\\Thank you very much guys.
I will dig around at the links I was given and see what I can come up with.
Thanks again,
Steve
///That is good to know. However, JOmega posed a legitimate question whether or not 1.25 is aligned with HP or Service Factor (SF). Please, would you confirm that reading once again?\\\