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  1. #1
    Join Date
    Apr 2018
    Posts
    2
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    McQuay Centrifugal

    Hey looking for some help here, I recently started to work on a McQuay PFH126 with two CE126 compressors on it. I found out that a complete rebuild of one on these compressors was done about a year ago and since then when the machine is running I am experiencing oil loss in that compressors oil sump and the other compressors sump becomes full. I have to then transfer oil from one sump to the other. This seems to be occurring more in low load situations. I was at the McQuay factory for another training and asked one of their engineers about this and he said that it sounded like a venting issue in the gear housing. He would not elaborate more on this only that I would need to run a line from the condenser to the gear housing with a ball valve to balance the pressure. I have been looking at this and really am confused, because the way I see it if the gear housing is not returning the oil to the sump then how is it getting back into the charge for the other compressor to pickup. My thoughts is this could be a problem on the front side or high speed side with the compressor not picking up enough oil.
    Any thoughts on this would be greatly appreciated?

  2. Likes polarman360 liked this post
  3. #2
    Join Date
    Dec 2015
    Location
    Washington, DC
    Posts
    201
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    Is one compressor running more loaded than the other? If you spend too much time running at low loads oil can be lost to the evaporator. If one compressor is running at a higher load than the other more oil will return to the more loaded compressor.

  4. #3
    Join Date
    Apr 2016
    Location
    Maryland
    Posts
    238
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    May I ask where the " Training " was and do you recall if the engineer was a person with many years of field service ?

  5. #4
    Join Date
    Jun 2014
    Posts
    25
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    Am having same problem with McQuay, peh048, R12, ce048 dual compressor system. One compressor was losing oil,now can't build up oil pressure. Maybe bad o ring. Any help apreciated

  6. #5
    Join Date
    Nov 2004
    Location
    up in the hizzy
    Posts
    2,816
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    Start by measuring the oil sump pressure (top middle vent port), use a single gauge, then measure the evaporator pressure, the sump pressure should be lower than evap.
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  7. Likes polarman360, CHILLERSVCMAN liked this post
  8. #6
    Join Date
    Jun 2014
    Posts
    25
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    CE 048

    Quote Originally Posted by valdelocc View Post
    Start by measuring the oil sump pressure (top middle vent port), use a single gauge, then measure the evaporator pressure, the sump pressure should be lower than evap.
    Thanks, will ck, oil pump was only building 5# pressure on start up before dropping out. Had changed oil pressure regulator. No difference. Hate to change oil pump without knowing for sure. Thoughts?

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