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  1. #1
    Join Date
    Aug 2016
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    Arlington, VA
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    Old Carrier Semi-Hermetic Compressor is locked up.

    Hello gang,

    I'm working on the air handler at my church, but I am a controls technician and I have very little experience with semi-hermetics.

    When I un-bolt the coupler, the motor shaft turns freely, but the compressor shaft is entirely locked up. This seems strange since it has been working up until recently. I honestly don't know if the compressor shaft is supposed to turn freely when it is powered down.

    But is there something I can do to free it up and get it working again? Or is it more likely that it finally locked up for good and it will need to be replaced? It is a very old unit. I wasn't able to find a nameplate on the compressor itself, but in the control cabinet is a Carrier nameplate with serial number 5786733.

  2. #2
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    Aug 2016
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    Arlington, VA
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    Thread Starter
    Actually, I should clarify. I'm not even sure I am calling the compressor by the correct name. The motor and the compressor are entirely separate, and I'm not sure I'm calling that the right thing. It is a reciprocating compressor.

  3. #3
    Join Date
    May 2004
    Location
    Salt Lake City/Tooele
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    Hard to say exactly why the compressor is seized and the cause. Would need to tear down the compressor to see what happened. Could have been oil related, refrigerant issues leading to liquid slugging or high head temps, or mechanical failure.
    Would probably need to call someone more experienced to investigatell and implement a plan of attack.

  4. #4
    Join Date
    Aug 2002
    Location
    Southold, NY
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    Where is this?

    You really need someone more knowledgeable on site to assist.

  5. #5
    Join Date
    Jun 2012
    Location
    Northern NV
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    We talking BELT or open SHAFT driven compressor here?

  6. #6
    Join Date
    Jul 2012
    Location
    WA
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    An open drive compressor shaft can sometimes be a little hard to get started turning by hand. What made you try to turn it by hand, is the motor drawing LRA?

  7. #7
    Join Date
    May 2004
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    Salt Lake City/Tooele
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    Quote Originally Posted by Juan Madera View Post
    We talking BELT or open SHAFT driven compressor here?
    I assume a direct coupled open drive set-up, since he states he removed the coupler and the motor side is spinning freely however the compressor side is possibly seized. Probably a Carlyle 5F or 5H series compressor.

  8. #8
    Join Date
    Jul 2005
    Location
    Tulsa
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    The Election History Engine
    Search a database of counting... Reddit posts from two top political subreddits starting from Nov 2, 2016.
    http://adestefa.com/HE/

  9. Likes YingGiang liked this post
  10. #9
    Join Date
    Feb 2004
    Location
    New Mexico
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    If the shaft won't turn with a pipe wrench (or equal) valve it off and recover the refrigerant. Pull the end bell. If it looks ok pull the heads. This effort is just so your report shows due
    diligence. I doubt anyone will want to overhaul it.I've seen open drives replaced with semi-hermetic. 06D etc.
    I should have played the g'tar on the MTV. MK

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

    SMW Lu49

  11. Likes lynn comstock liked this post
  12. #10
    Join Date
    Aug 2016
    Location
    Arlington, VA
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    Thread Starter
    This is fantastic. Thanks so much, gang. Yes, I am going to have to get someone more experienced involved with this. I wasn't able to get the coupler entirely removed because the shaft stopped with the set screw in the least accessible place (of course). And I didn't have a pipe wrench with me, so I kind of gave up. But I do think the compressor is locked up. It is quite old, so maybe time to replace it. The only thing is that it is so large and heavy, that it may be easier to repair in place. But I'll let the service company decide on that.

  13. Likes heatingman liked this post
  14. #11
    Join Date
    Jan 2003
    Location
    Kansas City
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    Maybe this

    Sent from my SM-G900V using Tapatalk

  15. #12
    Join Date
    Aug 2010
    Location
    Dearborn MI
    Posts
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    Rebuild it in place. The alignment of the motor and compressor shafts is CRITICAL and must be done by someone with experience. If the alignment is out by more then a few thousandths the new compressor will fail. Fixing it in place means no re-alignment because the casting didn't move to begin with. All of the Carrier 5F and 5H compressors are designed to be field serviced and all parts are still available. Find someone in your area to do it on sight. Did you change refrigerants and / or oil recently? That may have caused the failure. Whatever you do, DON'T PUT A PIPE WRENCH ON THE CRANKSHAFT TO TURN IT!!! If you can't turn it with a wrench using the bolt that holds the compressor hub on, the compressor is seized! Don't make it worse by ruining the taper of the shaft with a pipe wrench.

  16. #13
    Join Date
    Aug 2016
    Location
    Arlington, VA
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    Thread Starter
    Yes, that picture looks like the one I have been working with. Thank you so much Remanworld, that makes a critical difference. I have since passed the job back to the company that does their regular service, so hopefully they are able to fix it in place or find someone who can.

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