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  1. #1
    Join Date
    Jun 2005
    Posts
    5

    Question

    2 ton Copeland scroll compressor, 7 years old. Runs only 20 sec in hot day and the overload cuts off. Low pressure stay about 100 high 160. Colder day or night time runs continiosly but the lo and high are still 100/160. Both coils are clean, condenser fan runs good. The return pipe never gets cold. Is the compressor dead??

  2. #2
    Join Date
    Sep 2002
    Posts
    510
    It's dead.

  3. #3
    Join Date
    Jun 2005
    Posts
    5
    Thanks. I just bought a new one.

  4. #4
    Join Date
    Apr 2004
    Location
    Midwest
    Posts
    2,682
    The question I always ask my guys is "why did it die?"

    Make no mistake a 7 year old compressor just didnt die, it was murdered!

    Dont let anybody kid you, there is a reason that compressor failed and it's not becuase it was defective, old age, a lemon, hit by lightning, voltage spiking...

    You know all the popular answers techs give when they really dont know.

    Without knowing why the first compressor failed, stands to reason the second compressor will also have the same fate.

    Ask yourself,
    How much oil is left in the old compressor?
    Is the unit mis applied?
    Long line not done correctly?
    Low ambient not done right?
    Wrong metering device?
    Bad airflow?
    How much refrigerant did you take out, was it overcharged?

    You get the idea...the answer is out there!
    Live each day like it is your last, for one day you will be right!

  5. #5
    Join Date
    Jun 2005
    Posts
    5
    I'll pull the refrigerant Modnday probably has been overcharged. I found a old braizing job on the condenser coil probably the unit leaked out and has been repaired but not in the last 3 years. How long it takes to "die" overcharged compressor? Everything else looks good.

  6. #6
    Join Date
    Sep 2004
    Posts
    3,157
    How long it takes to "die" overcharged compressor? Everything else looks good.
    >--------------------------< usually about this long

  7. #7
    Join Date
    Jul 2000
    Location
    Columbia, SC. USA
    Posts
    1,143
    Is this a heatpump? If so, you could have a stuck reversing valve letting hot gas bypass back to the compressor and overheating it...your pump might be OK, but I would suggest further diagnostics..Good-Luck.

  8. #8
    Join Date
    Jun 2003
    Location
    Hell Hole Swamp
    Posts
    4,180
    Check the oil for a green color to it, you might have a mess in there

  9. #9
    Join Date
    Jun 2005
    Posts
    5

    Question

    not a heat pump. If the oil is green what does that mean?

  10. #10
    Join Date
    Jul 2000
    Location
    Columbia, SC. USA
    Posts
    1,143
    The green Slime has been Known to infect systems that have gotten moisture in them for one reason or annother...A hole in the condenser coil is one reason why I can think of, also not properly evacuating a system before charging, repairs made in the rain....various reasons. If you do find the slime, it's best to replace the entire system(including the lineset) this will assure you you aren't contaminating the rest of the system with it. I have tried several ways of cleaning this mess up before, and I can assure you from personal experience, It's not worth trying. I hope the green slime has not infected your system. Good-Luck. PS: since you have a straight cooling unit, and your pressure readings indicate your compressor isn't pumping, it's a good bet it's bad. Cheers.

  11. #11
    Join Date
    Apr 2005
    Location
    Richmond, Virginia
    Posts
    365
    How can you condem a compressor based on one pressure reading? If the compressor where not functioning both hi and low sides would be the same.

    Did you ohm out the compressor leads? A high resistance would indicate a compressor going bad.

    What were the running amps as compared to nameplate data?

    Jump out the low and high pressure switches and see what the pressures do that will tell you if there is a restriction in the line or it's overcharged.

    Find out why this one has gone bad, it worked for 7 years, don't throw good money after bad.
    Sean Cantrell

  12. #12
    Join Date
    Mar 2005
    Location
    Suppy NC
    Posts
    4,513
    have to go along with sean88. 100/160 no valves in a scrole to go bad. something else is happening in this system. even if the check valve goes it will still pump just have a loud swriling rattle when it shuts down. what type of metering devise is in the system. i think when you change the compressor you may have the same problem. if the senser is shutting down the compressor it may be defective and not the compressor. recheck the system before you replace it

  13. #13
    Join Date
    Jul 2000
    Location
    Columbia, SC. USA
    Posts
    1,143
    Originally posted by krasi_k
    2 ton Copeland scroll compressor, 7 years old. Runs only 20 sec in hot day and the overload cuts off. Low pressure stay about 100 high 160. Colder day or night time runs continiosly but the lo and high are still 100/160. Both coils are clean, condenser fan runs good. The return pipe never gets cold. Is the compressor dead??
    Gentlemen: How in the F*&^ is this guy going to have a compressor there in a straight cooling system and it be good?
    On a hot day the compressor runs for a while and overheats this is a fact we know...if the suction pressure was 100 on a hot day even it would most likely be flooding refrigeant back unless it was 100 degrees inside.(assuming the compressor was pumping) and the suction line would be quite cold right? Not to mention the fact that if the compressor was pumping on a hot day the head pressure would be a hell of a lot higher than 160psig. The only way I could see him reading these pressures on a condensing unit that had a functional compressor is if he had his guage manifold cracked and was allowing refrigerant to bypass through his manifold.I may be missing something here, but I think he's got a piece of trash in the pressure relief, or there is junk in the scroll itself. Not trying to slam anyone here, just putting out an educated guess. Good-Luck.

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