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  1. #1
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    Bitzer Compressor - Low oil pressure alarm.

    Hello Guys...


    Need some help here please:


    I have a 30 HP Bitzer screw compressor on a refrigeration rack system with an Emerson CPC 835-0400 controller.

    The problem is that the compressor keeps alarming and shuts down. The alarm says low oil pressure/low suction. When onsite, everything looks normal, good suction pressure, good oil pressure and the alarm doesn't come back for days. There's 4 compressor in the circuit and it only happens on this compressor (#2).

    Any ideas or suggestions ?


    Thank you so much for any input.


    Rudy

  2. #2
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    None of the Bitzer screws I've seen had oil pumps, they typically use optical sensor for oil safety, maybe you should start by posting the compressor model.
    There is not better place for the working men than the union! 100% UA the only HVAC union!

  3. #3
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    Is it on a pump down?

  4. #4
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    Thread Starter
    Hi guys,

    Yes its in a pump down... BSE170

    Alarm says very low oil pressure. It has a noisy start (as if it was liquid flooded ) and goes away after 30 seconds. Then I can hear the 75% unloaded engaging, right after that compressor gets alarmed and shuts down.

    Any ideas?

    Thanks

  5. #5
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    That number is for oil.




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  6. #6
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    Quote Originally Posted by jlunaCR View Post
    Hi guys,

    Yes its in a pump down... BSE170

    Alarm says very low oil pressure. It has a noisy start (as if it was liquid flooded ) and goes away after 30 seconds. Then I can hear the 75% unloaded engaging, right after that compressor gets alarmed and shuts down.

    Any ideas?

    Thanks
    Post the compressor model number or take a picture, I never seen a Bitzer screw equipped with oil pressure switches or transducers, if its 75% unloaded that means its 25% loaded, are you taking infinity capacity control or step load? either way I never been able to hear one "engaging" are sure its not a recip? cause I dont think Bitzer makes a 30hp screw they start at 50hp.
    There is not better place for the working men than the union! 100% UA the only HVAC union!

  7. #7
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    Thread Starter
    Model number is CSH9573-180Y

    Step load.

    * I mixed the other post with this one. Different compressor same type of issue.

  8. #8
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    Quote Originally Posted by heatingman View Post
    That number is for oil.




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    True .....it makes one wonder....
    There is not better place for the working men than the union! 100% UA the only HVAC union!

  9. #9
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    How many compressors on the rack?

    Is there a secondary oil separator for the common rack?


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  10. #10
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    Thread Starter
    There’s two circuits, no secondary oil separator.

  11. #11
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    Are the compressors piped in Tandem, or truly separate circuits?


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  12. #12
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    Thread Starter
    Hi Heatingman,

    They’re truly independent circuits not piped in Tandem.

    Thanks

  13. #13
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    You need to figure where is the alarm coming from, there is not oil pump in that compressor so is not an oil pressure related alarm, now when compressor starts and trips hows the oil level in the sigh-glass? assuming the rack ran fine for years and just recently started to have issues, tell us more about the time line.
    There is not better place for the working men than the union! 100% UA the only HVAC union!

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