Evaporator blower shuts down after several minutes

Reply

  #1  
Old 07-12-10, 08:58 PM
M
Member
Thread Starter
Join Date: Nov 2008
Posts: 2
Received 0 Votes on 0 Posts
Evaporator blower shuts down after several minutes

I have an old Fedders central air. Noticed that air wasn't moving from the vents. Went up into the crawl space to take a look. The fan wasn't moving, but the outside compressor seems fine. I can hear coolant moving. No evidence of ice. After shutting the system down for about ten minutes the fan will come on for several minutes, then just shut down. Cycle is repeatable. The motor is too hot to touch. What I take to be the capacitor looks fine. Some dust bunnies, but, outside of possible overheating, nothing I can identify as wrong. Is there something shutting the fan down when overheated? If so, does the motor need replacing?
Photo of fan and capacitor: fan on Flickr - Photo Sharing!
Model number:fedders on Flickr - Photo Sharing!

Thanks,
Mike Holloway
 
Sponsored Links
  #2  
Old 07-13-10, 08:05 AM
M
Member
Join Date: Sep 2009
Location: U.S. Midwest
Posts: 1,340
Received 0 Votes on 0 Posts
My theory is that the fan motor overheats due to a weak capacitor. But first, see if the fan spins freely manually. And, add a few drops of oil to the motor's oil ports.
 
  #3  
Old 07-13-10, 08:21 AM
M
Member
Thread Starter
Join Date: Nov 2008
Posts: 2
Received 0 Votes on 0 Posts
Thanks. It seems that A/C motors do have a thermal shutoff to protect from overheating. Seems this one's shut off is working fine. I'm assuming at this point that I have to clean things out, and, like you suggest, add oil. The fan doesn't seem to have much trouble turning, but apparently it needs to be easier.
How do I locate the oil ports? Are they obvious?

Thanks
 
  #4  
Old 07-14-10, 02:54 PM
M
Member
Join Date: Sep 2009
Location: U.S. Midwest
Posts: 1,340
Received 0 Votes on 0 Posts
Originally Posted by MikeH View Post
How do I locate the oil ports? Are they obvious?
The oil ports should be lubed every year or so, but if the fan turns freely, that won't solve your failure-to-start problem. I would replace the capacitor.

I see one oil port at about 11:30 in your photo. You pull out the little plug with a fin-bladed screwdriver or with needle-nose pliers. Add about 3-4 drops (no more) of electric motor oil and replace the plug.

There will be another, similar oil port on the opposite end of the motor. You'll have to remove the motor from the fan shroud to get at it. Remove the three cap screws to remove the motor.

I would remove the motor first, oil both ends, and replace the two plugs before reinstalling the motor. It's easy to drop a plug through the fan blades, and the plug will wind up at the bottom of the shroud. Then you'll have to disassemble again to recover the plug.
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: