Contact US

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!

*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

1/15 hp blower motor

1/15 hp blower motor

1/15 hp blower motor

Hello everybody!

I have been looking through the forums wanting to make my first post a correct one but I haven't found anything that relates directly to what I'm sure is a minor issue.

I am on my Condo board and are trying to rectify some horrible repairs our recently released property management company has performed, one being seriously hampered dryers. I am repairing the ducts that are plugged and found a serious bottleneck in the form of a duct boost fan in the attic.

It was killed off by the a**holes that installed a new furnace in 2012 and new wired the fan back in and has collected so much lint and other contaminants it resembles something an 800lb yeti coughed up. So I pulled the unit for cleaning and testing. It is a Braun 1/15 hp duct booster with an 9" squirrel cage which should handle the job fairly easily (it's only a 3 storey building).

I did wire it back in to see if it worked at all but just sat humming without motion but being literally buried in 2" of lint barely visible I blamed weight for it's inability to spin. However it would freewheel by hand rather easily. It has been cleaned and I split the motor to uncover fairly seized bearings with cracked plastic spacers and a ton of red rust dust. The winding was in good shape and after cleaning the stator it too was in usable condition but had some big scratches on one of it's ends which I would expect with the stator walking from it's bad bearing spacers, this I can rectify easily. I reassembled the motor for a quick test and it fired up.

It was a little noisy but actually worked ok until I grabbed the outer cage wheel to see how much power it still had and then the motor seemed to jam. I tried to coax it back into motion but it seemed to fight wanting to turn but kept humming until I killed the power at which point the motor freed up. When I plugged it back in it locked up again and refused to move.

I am a little puzzled, the stator does not have enough play in it to contact the winding and the bearings are spinning like new. Would a phase shorting do this? It has no start capacitor and the only thing I can think is somewhere the winding is back feeding and stalling the motor trying to spin it in both directions at the same time, but I don't even know if it's possible and if it is why does the cage seem to grind when I move the cage still powered on?

I'm sure we're into a new motor but I'd love to know what the heck does this.

RE: 1/15 hp blower motor

Go to Grainger and get a replacement unit ,ie, motor and squirrel cage and be done with it. Don't forget Grainger has on a line catalog and when you purchase it, it must be done under a contractor, manufacturer, mechanical or some other type of designer designation in your purchase. Grainger will not sell to private home owners.

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! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close