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A/c troubles

Pretty new to working on big commercial equipment most worked on residential equipment.Have a 20 ton 2 stage condensing unit with two 10 ton evaporators. It has a common circuit branching into the two evaporators two txv and one liquid line solenoid valve. First stage compressor is coming on and pumping into the two evaporators at once.

Not 100% sure but shouldn't the evaporators be stage with compressors? If one compressor is running should it only be feeding 1 evap?


  • Techman
    Techman Member Posts: 2,144
    edited June 2010

    Could be, may be, might be, it kind of depends on the mfg's specs.What is this system cooling off ?Make ,model?Also,I think,that I think that both compressors might have to come on /off together to prevent on oil hogging issue.Is there an oil equilizer setup on the comps?Just like on a refrigeration rack!
  • Empire_2
    Empire_2 Member Posts: 2,343
    Your used to do this.

    York used this set up a while back.  The idea is the common suction is designed to bring on 50% of the total capacity under, usually non peak loads.  Kind of like an unloader.  Oil migration was never a problem as far as I could see. 

    Mike T.

    Hey Terry?
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