Results 1 to 6 of 6
  1. #1
    Join Date
    Feb 2007
    Posts
    29

    85 Carrier Split System - Minimum Cooling

    I am working on a 1985 model Carrier 3.5ton split system that is giving me a very hard time. System supply air temp is at about 72 degrees and I cannot get it to reduce. Gauges show low side = 90 psi and high side = 318. Ambient outdoor temp 99. Low side line temp about 67 - 72 and high side 130. Superheat around 14 and subcool 5. I have tried reducing pressure by introducing water to the condensor coils during operation. This presented no change in supply air. Check ducts for leaks and all are in tact. One thought that has come to mind is that the condensor fan may not be seated on the shaft in the proper position to the venturi. I am about at the point of recovering the entire system, flushing, pulling vaccum, and recharging to ensure there are no non-condensables and weigh in charge to ensure proper 22 starting point for proper charge. Any advice would be appreciated.

  2. #2
    Join Date
    Feb 2007
    Posts
    29

    Smile Fixed

    Adjusting fan on motor shaft dropped pressures some and decreased supply air temp but not enough. Decided to go ahead and evacuate system and weigh in charge. System is operating efficiently again.

  3. #3
    Join Date
    Aug 2011
    Posts
    568

    Hmm

    Quote Originally Posted by dhagar View Post
    I am working on a 1985 model Carrier 3.5ton split system that is giving me a very hard time. System supply air temp is at about 72 degrees and I cannot get it to reduce. Gauges show low side = 90 psi and high side = 318. Ambient outdoor temp 99. Low side line temp about 67 - 72 and high side 130. Superheat around 14 and subcool 5. I have tried reducing pressure by introducing water to the condensor coils during operation. This presented no change in supply air. Check ducts for leaks and all are in tact. One thought that has come to mind is that the condensor fan may not be seated on the shaft in the proper position to the venturi. I am about at the point of recovering the entire system, flushing, pulling vaccum, and recharging to ensure there are no non-condensables and weigh in charge to ensure proper 22 starting point for proper charge. Any advice would be appreciated.
    the unit is 27 years old, kick it to the curb!

  4. #4
    Join Date
    Feb 2007
    Posts
    29

    Wink Replacement is next...

    If i can pull this one through one more season then I will have the go for the replacement. System runs very well. Would not even know the age if just went by efficiency and cooling ability. Combustion chamber is worn though so I am sure to see the swap out before winter. :-)

  5. #5
    Join Date
    Apr 2011
    Posts
    53
    would never have wasted the time to do what you did. throw it in the trash!!! curious, whats the electric bill like?

  6. #6
    Join Date
    Feb 2007
    Posts
    29

    Lost some time now for the new install later...

    I am not sure electric bills as it is not my equipment. She mentioned one of the last bills was around $215. I gave up some of my time but in the end get the replacement job. She just needed to get through the rest of the summer. So win-win in the end.

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