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low suction pressure

Trying to treat a problem AC two air handlers set to one condensor with tees.

That when left on overnight, trips the breaker. when running in the day pressure reads 162/58. Cleaned coils no airflow obstructions. cools the space fine. The condensor may be oversize. I would suspect that the breaker trips when ther is some return liquid due to cooler nights.

two quick fix solutions? Add a condersor fan control to keep pressure higher. or Add a bypass to the compressor and set it to raise the pressure enough or is there a self regulating valve that can do this with prescision. Whats your take on this??


  • Empire_2Empire_2 Posts: 2,343Member
    edited June 2012

    Need some more info.  Describe the system, include temps in and out, and what application is it being used in?  Check the size of cond. and evap because you said it might be over sized.  All vital info required to help you out.  Also, the breaker tripping has nothing to do with slugging liquid.  If so your valves would be gone.  Give some amp draw readings and equipment ratings. 

    Mike T.
  • mormor Posts: 42Member
    edited June 2012
    More info

    Thanks. The comp is rated at 25a draw I usually get 24 start going down to 20. seems to be a 5 or 6ton [based on size and a 60 model number] used for AC feeding two air handlers 2 & 3 ton no txv  which both are always on. The first time I touched the cond I tripped the breaker by twice actuating the contactor. I added a delay to prevent the Tstat from doing that.

     At some point in testing I did get 125a draw on start. The customer says this was always a problem job with the breaker tripping after two or three days on, now it's gotten worse that you can't have the unit on overnight. ???? Thank you
  • TechmanTechman Posts: 2,144Member
    Tripping breaker

    Does the comp have "hard start components"? With 162/58 psig what was the in/out temps?What size and type of C.B. is there?
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