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  1. #1
    Join Date
    Jun 2007
    Location
    Tennessee
    Posts
    26

    Modulating pressures

    I have a York Comm. package unit, 4Tons, that has a scroll and the pressures range from 64 to 72 on low side, 240 to 275 on high side. I have no condensation to speak of. I have removed the compressor and recovered approx. 20 oz. of oil. I can say that the oil was not discolored. I then remove the orafice and purged the system with nitro. I didn't get very much oil. I even cut a hole in the lowest point of the common return of evap to find only a few more drops of oil. I changed out the filter drier and weighed in the charge. Now I have a swing of 70 to 72 and 260 to 275.
    Still sounds like I have oil in the evap. ???? Is there a better way to remove this oil??? If I am thinking right or wrong someone tell me so. And the 100.00 question for me is why did it migrate. I did notice a new blower motor. Did the oil find its way there when it went down and froze the coil?

  2. #2
    Join Date
    Sep 2002
    Location
    Hampton Roads, Virginia
    Posts
    1,626
    Quote Originally Posted by Icecreamman View Post
    I have a York Comm. package unit, 4Tons, that has a scroll and the pressures range from 64 to 72 on low side, 240 to 275 on high side. I have no condensation to speak of. I have removed the compressor and recovered approx. 20 oz. of oil. I can say that the oil was not discolored. I then remove the orafice and purged the system with nitro. I didn't get very much oil. I even cut a hole in the lowest point of the common return of evap to find only a few more drops of oil. I changed out the filter drier and weighed in the charge. Now I have a swing of 70 to 72 and 260 to 275.
    Still sounds like I have oil in the evap. ???? Is there a better way to remove this oil??? If I am thinking right or wrong someone tell me so. And the 100.00 question for me is why did it migrate. I did notice a new blower motor. Did the oil find its way there when it went down and froze the coil?
    I don't think oil is the problem, give us more information, superheat, sub cooling delta T across the coil, from take a better diagnosis can be make.

    Kevin
    "Profit is not the legitimate purpose of business. The legitimate purpose of business is to provide a product or service that people need and do it so well that it's profitable."

    James Rouse

  3. #3
    Join Date
    Apr 2007
    Location
    Rossland, B.C.
    Posts
    95

    Angry

    I'll bet that pesky oil n' condensate eater visited that unit. Then it plugged it up.

  4. #4
    Join Date
    Dec 2006
    Location
    Middle Tennessee
    Posts
    11,347

    *

    how many mics did you evacuate it to

    you might possibly have moisture in the system!



    .

  5. #5
    Join Date
    Apr 2007
    Location
    Philadelphia
    Posts
    2,192
    i agree you need a micron gauge

  6. #6
    Join Date
    Aug 2002
    Location
    Southern NJ
    Posts
    962
    Just a question, so dont get mad. Why did you pull the compressor? What were the space conditions like? Was the evap coil wet? What kind of space is this unit controlling? Did you clean the condensor coil if the pressure was out of whack with the ambient temp? Has someone worked on this system prior to you being there? I know that's more then one question!

  7. #7
    Join Date
    Jun 2007
    Location
    RI
    Posts
    121

    Why?

    Why are you doing so much to this unit?

    If your pressures were 325 and 45 then do some work. But don't go reclaim crazy on the poor little guy.

    What is your outside temp? Did you clean the condenser?

    With a unit running unloaded and no condensate comming out I had 240/70 psi....seems ok?? It wasn't. Discharge was about 60 degrees. I washed the condenser and my pressures went to 170/55. THEN I had real numbers to work with.

    On average when I walk up to a condenser that hasn't been cleaned in a couple of years I chop 50-90 psi off the headpressure. Once I know I have a clean and sound running AC unit then I look at pressures and superheats.

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