×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Old AC Motor varispeed, possible?

Old AC Motor varispeed, possible?

Old AC Motor varispeed, possible?

(OP)
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

RE: Old AC Motor varispeed, possible?

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?

RE: Old AC Motor varispeed, possible?

(OP)
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.

RE: Old AC Motor varispeed, possible?

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.

RE: Old AC Motor varispeed, possible?

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.

RE: Old AC Motor varispeed, possible?

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

RE: Old AC Motor varispeed, possible?

(OP)
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

RE: Old AC Motor varispeed, possible?

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.

RE: Old AC Motor varispeed, possible?

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?\\\

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources