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  1. #1
    Join Date
    Aug 2009
    Location
    Manchester
    Posts
    178
    Rep Power
    15

    Airedale chiller fault



    Hi all

    called to a Airedale compact chiller (air cooled) KKCS9-K66/S model working as part of a close control system via a indoor AHU. The room temp had gone 2 deg above setpoint and was struggling to get it down. Indoor coil was warm so went to check chiller. Compressor was running but was encased in 3 inches of ice. Bottom of txv iced and all uninsulated sections after txv iced back to compressor. Stopped unit allowed to thaw. On restart suction 1.5 bar discharge 18 bar. Reftigerant R407C unit evaporating at -15 superheat high 33.8degC Subcooling low 4.5 DegC. Liquid line sight glass foaming then clear for a second and starts to foam again. Compressor oil level low also foaming. Compressor starts to freeze almost immediately following startup. Checked system charge 2.84Kg short. Notice oil seeping from access port at evaporator inlet engaged schrader and oil pissed out. Initially thought it was oil/ water mixture and that the evaporator had failed. Put system on pressure test left overnight pressure held at 21 bar. Customer tells me the unit has been maintained but refrigerant charge been untouched since first install. Since we don't have a leak I'm thinking faulty TXV and will replace that. Do people agree or should I be looking else where maybe blow through with OFN evacuate and recharge with correct factory charge first could a 1/3 reduction in refrigerant charge simply be the cause. Plus stupidly I didn't have a fiddle around with the txv prior to recovering the gas was late in the day and just wanted to get home so went with the obvious. What you think any advise gratefully received



  2. #2
    Join Date
    Dec 2008
    Location
    UK
    Posts
    568
    Rep Power
    24

    Re: Airedale chiller fault

    R3407C when it losses part of its charge performs quite strangely. it could just be short of gas along with your original thoughts and you could have excess oil entrainment in the evaporator. Hopefully when you get the full gas charge in and the TXV changed, the oil should eventually return to the compressor.
    Mobile A/C at its best, see avatar.
    Bedford. Now retired and trying to relax.

  3. #3
    Join Date
    Oct 2001
    Location
    Nottingham UK
    Posts
    5,733
    Rep Power
    51

    Re: Airedale chiller fault

    It's impossible to diagnose other operating problems until you are sure that the gas charge is correct.

  4. #4
    Join Date
    Aug 2009
    Location
    Manchester
    Posts
    178
    Rep Power
    15

    Re: Airedale chiller fault

    Replaced TXV and recharged all is well chiller running ok

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