Page 1 of 2 12 LastLast
Results 1 to 20 of 22

Thread: Condenser fans , Sleeve or Ball bearing

  1. #1
    Join Date
    Sep 2002
    Location
    Virginia
    Posts
    7,163
    Post Likes

    Condenser fans , Sleeve or Ball bearing

    Im always torn on which to buy

    Do you really think there is a difference in quality ?

  2. #2
    Join Date
    Aug 2002
    Location
    Southold, NY
    Posts
    28,790
    Post Likes
    Wasn't aware there was a choice?

  3. #3
    Join Date
    Dec 2014
    Posts
    3,164
    Post Likes
    Ball bearing if using variable speed control, and you want slow fan speeds.
    Otherwise sleave bearing ok. Usually not recommended to go below 1/2 rated voltage on sleeve bearing, due to insufficient heat generated at sleeve bearings for lubrication. (Oil impregnated bearings)

    Sent from my SM-G950U using Tapatalk

  4. #4
    Join Date
    Jul 2013
    Location
    Richmond, VA
    Posts
    5,233
    Post Likes
    Quote Originally Posted by icy78 View Post
    Ball bearing if using variable speed control, and you want slow fan speeds.
    Otherwise sleave bearing ok. Usually not recommended to go below 1/2 rated voltage on sleeve bearing, due to insufficient heat generated at sleeve bearings for lubrication. (Oil impregnated bearings)

    Sent from my SM-G950U using Tapatalk
    Huh, I never knew that. So for example with Carrier RTUs that have a Motormaster, those condenser fan motors need to have ball bearings?

  5. #5
    Join Date
    Dec 2011
    Location
    Maryland
    Posts
    603
    Post Likes
    Quote Originally Posted by CircusEnvy View Post
    Huh, I never knew that. So for example with Carrier RTUs that have a Motormaster, those condenser fan motors need to have ball bearings?
    No, but they will last longer.

  6. #6
    Join Date
    Sep 2002
    Location
    Virginia
    Posts
    7,163
    Post Likes
    Thread Starter
    the motor controllers I've installed have a setting for bushings / bearings

  7. #7
    Join Date
    Oct 2011
    Location
    Chicagoland Area
    Posts
    9,765
    Post Likes
    Ball bearing is a better quality. I'd choose a ball bearing first for both shaft down and horizontal mount.
    Officially, Down for the count

    YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

    I know enough to know, I don't know enough
    Your dream is your dream. It's nobody else's dream. You're going to have to do it for yourself"

  8. #8
    Join Date
    Dec 2014
    Posts
    3,164
    Post Likes
    Quote Originally Posted by CircusEnvy View Post
    Huh, I never knew that. So for example with Carrier RTUs that have a Motormaster, those condenser fan motors need to have ball bearings?
    You can run sleeve bearing motors. Some last a long time. Probably dependent on setup speed and duration of slower run times.

    This Carrier instruction sheet says.....

    Sent from my SM-G950U using Tapatalk

  9. #9
    Join Date
    Nov 2011
    Location
    USA
    Posts
    2,528
    Post Likes
    For PSC condenser motors, ball bearing is all I buy...I haven't had any bearing failures with them. With sleeve bearing motors, the bearings were the first thing to go...

  10. #10
    Join Date
    Feb 2004
    Location
    New Mexico
    Posts
    9,678
    Post Likes
    The failure mode of sleeve bearings is because they are lubricated by capillary attraction and need the bearing to heat up in order to draw oil in from the wick. If the motor is slowed down to xx speed the bearing runs dry.(xx speed because I don't know what the failure speed is) (Someone does. somewhat less than full tilt.)
    I learned this from a contractor that installed a bunch of speed controls and had a bunch of bearing failures. At the time it was determined the speed controls were the problem and that ball bearings wouldn't be effected. Other than that there is no real reason sleeve bearings won't work fine on their intended application.
    Give me a relay with big enough contacts, and I'll run the world!

    You can be anything you want......As long as you don't suck at it.

    If a person wants to create a machine that will be more likely to fail...Make it complicated.

    USAF 98 Bomb Wing 1960-66 SMW Lu49

  11. #11
    Join Date
    Nov 2011
    Location
    USA
    Posts
    2,528
    Post Likes
    Quote Originally Posted by Snapperhead View Post
    Im always torn on which to buy

    Do you really think there is a difference in quality ?
    Quote Originally Posted by Saturatedpsi View Post
    For PSC condenser motors, ball bearing is all I buy...I haven't had any bearing failures with them. With sleeve bearing motors, the bearings were the first thing to go...
    The point I didn't quite make...the aftermarket, sleeve bearing, 1075 rpm, PSC condenser motors, running at 1075 rpm, were experiencing bearing failure within 2 or 3 years...sometimes, less than that.

    So, you conclude with the same old worn out expression...they don't make stuff like they used to.

  12. #12
    Join Date
    Mar 2015
    Location
    Medford, N.Y.
    Posts
    7,038
    Post Likes
    The better motor is the ball bearing motor. Way back in 72' my boss did lots of Carrier MotorMaster set up's. There was no choice about it. If you wanted a MotorMaster for head press control you put in the REQUIRED motor,a ball bearing motor.

  13. #13
    Join Date
    Feb 2004
    Location
    New Mexico
    Posts
    9,678
    Post Likes
    Quote Originally Posted by Saturatedpsi View Post
    The point I didn't quite make...the aftermarket, sleeve bearing, 1075 rpm, PSC condenser motors, running at 1075 rpm, were experiencing bearing failure within 2 or 3 years...sometimes, less than that.

    So, you conclude with the same old worn out expression...they don't make stuff like they used to.

    You haven't told why they failed. There are a lot more small motors running with sleeve bearings out there than ball. Both types of bearings can't be have lateral loading.
    Because so many sleeve bearings motors are successful there seems to need another explanation why you have failures.
    Give me a relay with big enough contacts, and I'll run the world!

    You can be anything you want......As long as you don't suck at it.

    If a person wants to create a machine that will be more likely to fail...Make it complicated.

    USAF 98 Bomb Wing 1960-66 SMW Lu49

  14. #14
    Join Date
    Jun 2012
    Location
    Northern NV
    Posts
    2,149
    Post Likes
    I honestly never knew that sleeve bearing were ever installed on a condensing unit for a/c... Always was ball bearings as they last longer and handle the thrust load better. Only real shortcoming is they are nosier which is why sleeve bearings are used in the indoor a/h.

    Fractional hp refrigeration condensers? They tend to go with unit (sleeve) bearing motors. Probably because they are located in the same equipment indoors.

    Some of the new R290 coolers I'v had are using box fans. Much nosier than the unit bearing ones..

    Sleeve bearing probably fails sooner with propeller type air mover as they have a high thrust load.

  15. #15
    Join Date
    Nov 2011
    Location
    USA
    Posts
    2,528
    Post Likes
    Quote Originally Posted by hvacker View Post
    You haven't told why they failed.
    Because so many sleeve bearings motors are successful there seems to need another explanation why you have failures.
    How the hell would I know? The bearings either seized or got sloppy (clearance). I remove a 20 year old, totally enclosed shaft down motor and replace with a similar design shaft down motor...the info on the box said "Condenser Motor". Motor guru's tell us to match the HP, FLA, voltage, frame etc when replacing motors. That's what I do.

    I don't remember the particular brand or motor specs, but I have always pretty much stuck with AO Smith or Emerson and kept up with the name changes...and learned (the hard way) to stay away from the cheap "store brand" motors.

    Maybe the faulty motors were spec'd in some way that didn't meet the 20 year old motor spec's...I don't know. The box said "Condenser Motor"...I installed it on a condenser and the bearings failed. If it ain't due to cheap s**t...you tell me.

  16. #16
    Join Date
    Dec 2005
    Location
    Cincinnati, Oh
    Posts
    7,550
    Post Likes
    How can i figure out how to know if an existing motors is ball or sleeve?

    Like if you walked up to an old unit, or couldn’t find a spec sheet

  17. #17
    Join Date
    Dec 2011
    Location
    Maryland
    Posts
    603
    Post Likes
    Quote Originally Posted by hvacvegas View Post
    How can i figure out how to know if an existing motors is ball or sleeve?

    Like if you walked up to an old unit, or couldn’t find a spec sheet
    Give the shaft a tug ...no, seriously...a sleeve bearing motor generally has some endplay and a ball bearing motor will not. I actually picked that up from someone here, might have been hvacker.

  18. #18
    Join Date
    Jun 2012
    Location
    Northern NV
    Posts
    2,149
    Post Likes
    Have replaced an Aaon 480V single phase condenser fan motor with a GE and had it fail in short order. Got an OEM from a rep and it continues to work years later. Not sure why as the specs looked to be the same...

  19. #19
    Join Date
    Sep 2002
    Posts
    27,737
    Post Likes
    Balls are better. Sleeves are quieter.

    Sleeves require some kind of axial / thrust 'bearing' arrangement as a sleeve bearing does not inherently provide it.

    PHM
    --------



    Quote Originally Posted by Snapperhead View Post
    Im always torn on which to buy

    Do you really think there is a difference in quality ?
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  20. #20
    Join Date
    Jan 2015
    Location
    Iowa
    Posts
    1,791
    Post Likes
    The sticker/name plate on the motor should tell what bearing are in the motor

    Ball bearings are better than sleeve for almost every situation

    Some need to be re-lubricated some do not

    Here I go thinking again, but I thought most of the multiple position fans had one ball bearing (fan side) and one sleeve bearing just because of the lateral movement. I know I have fought with several motors over the year with shaft up or shaft down position and wether the motor would start and run correctly or not. The fix was to make sure the motor had ball bearings

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •