Results 1 to 7 of 7
  1. #1
    Join Date
    Jul 2011
    Location
    Minn
    Posts
    9

    Oil pressor switch

    Have a 5 hp Copeland from the1980s old but still working. The oil presser switch tips out. other tecs have worked on it over the years.The pump has been changed,valve plate replaced (not holding vac.),presser switch replaced.some oil was added. still tip out Now I am called. The unit first started with 502, about 95 they convert to mp 80. He put in a new 10 door and the tec converted to r408. Where do i start looking i normally work on small stuff.

  2. #2
    Join Date
    Dec 2012
    Location
    Lowell,MA
    Posts
    50
    if it is a 3 ph comp try to reverse phasing on it, had an old timer tell me to do that once and it worked, got better pressures, it did trip oil pressure switch a week later, and found there is apick up tube inside that has a screen on it that has to be cleaned once in awhile call manufactures rep and ask about screen, could be partly/ totally blocked

  3. #3
    Join Date
    Jan 2010
    Posts
    6,263
    Check your net oil pressure.

  4. #4
    Join Date
    Jul 2011
    Location
    Minn
    Posts
    9
    I reversed it forgot i did that. where is that pickup tube?

  5. #5
    Join Date
    Jul 2011
    Location
    Minn
    Posts
    9
    tomorrow i will get presser readings I know that would help i will post tomorrow night.

  6. #6
    Join Date
    Jul 2011
    Location
    Lehigh Valley, PA
    Posts
    436
    Could it be flooding back at all? Maybe on start up? And tripping?

  7. #7
    Join Date
    Aug 2010
    Location
    Dearborn MI
    Posts
    103
    There is no oil pick up tube in a Copeland compressor. Maybe you were thinking of a Carlyle. Underneath the oil pump and to the left is a small diamond shaped cap. Pump down the compressor and remove the cap. Be careful, there is a spring behind it! Drain the oil and inside the casting you will find the oil pick up screen. Remove it and clean it with whatever solvent is available. Put it all back together and try it. Honestly though, it sounds like a flooded start. The liquid in the crankcase floats the oil above it. On start up the oil pump cannot prime because it is sucking the too thin liquid refrigerant. Then it times out and you get called. Does it have a crankcase heater? Does it work? Can you add one? The early MR Copelands like you have require a strap on heater on the bottom plate. Its not hard to do and you might fix the problem.
    Ray

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