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Thread: Trane chiller

  1. #1
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    Trane chiller

    I have a Trane model number cgacd106rknkk62k3g serial j91f63976. I am having trouble with one circuit freezing at the barrel sh 12 sc 25 nee expansion valve and power head new driers running at 40/240 with r422d in place of r22. The compressor is fully loaded. any suggestions?

  2. #2
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    What are your water temps and refrigerant temps? Does it start frosting when it runs by itself or with the other circuit running? Have you checked for correct water flow? Is it glycol or water?
    Need more info to help.
    -----Stop, step back, relax and have another go at it.-----

  3. #3
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    Water flow is not an issue I can run the r22 circuit with no issues at all the ref temps for the 422d are 19/110 r22 is 38/138 temps the loop system is water. It's freezes within five minutes either with one circuit running or both

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    138f SCT? 330 HP on the 22 side? High ambiant?

    Is the R422d side still iced up, resulting in the consistent 12f suction temp? Is there a way the flow may not be equal?



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  6. #5
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    R22 side psi is 65/275. I am wondering if the barrel plate gasket is blown causing the liquid to bypass tubes and cause this issue for the r422d side

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    You are running 1 Circuit R22 and the other Circuit R422d? That seems dumb and dangerous (not life safety dangerous...there are dumb techs running around dangerous...defective refrigerant divider plate mixing refrigerant dangerous).

    what expansion valve did you put in? It is also possible that your barrel is shot...the water barrel divider plates specifically.
    Don't step on my favorite part of the Constitution just to point out your favorite part.

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  9. #7
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    138f is 333 psi. Maybe that's your DP, and the LLP is 275? That would be 58 psi drop thru the condenser.

    Do the sensors work with r422d?
    I've read a Trane bulliten approving only M099, but that may have changed.
    At any rate, there's others with way more knowhow on this than me. Jayguy is one of them. And Bennyd



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    Last edited by icy78; 09-08-2017 at 05:28 PM.

  10. #8
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    I'm thinking the r422d has different properties. Good superheat, so the TXV is working correctly. Subcooling seems a little high to me.
    I would run each circuit individually and check approach and saturated refrigerant temp on the evaporator... with the same water flow.
    What is your chilled water setpoint?
    Crap, hit send too early! For argument sake, nothing against you, but are you using dew or bubble for your superheat calculation? R422d has a 6.5° glyde.
    I'm having a hard time with the 40psi/12° suction AND 12° superheat. Sounds like the expansion valve isn't opening enough or too small, but your superheat measurement suggests otherwise. Also, that's a HUGE approach, which would also suggest not enough refrigerant.
    And if the plates are stacked up, won't both circuits be doing the same thing?
    -----Stop, step back, relax and have another go at it.-----

  11. #9
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    I've compared the two cicuits to one another and 422d is almost like 22 . Also if the two circuits were crossing over then when I evacuated circuit to make repairs I would have psi rise after ten min or more. I am using bubble for reference and digital gauges.

  12. #10
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    You were using the DEW POINT scale (as you should be) for the Suction side. 40 psig is approximately 19.4F saturated temperature DEW POINT.

    240 psig is approximately 110F DEW POINT (Discharge/vapor) and 105.8F BUBBLE POINT (Liquid line). I am not sure which High side measurement you collected.

    it is true that you would have seen a rise in pressure when you evacuated if the refrigerant divider plate gasket was leaking. I am not talking about it leaking today. I am talking about it leaking EVER. Also, if the next tech comes along and thinks Circuit #1 is Circuit #2 then starts dumping refrigerant into the wrong side...that's all I was referencing.

    as for the barrel plates, the water comes into it from the side and also exits from the side of the barrel. When the plates stack up, they push all the way to one end of the barrel. The water is then no longer being forced over both refrigerant circuits. It enters the barrel, pretty much runs down the inside of the barrel (which is primarily 1 refrigerant circuit) and then exits. Very, very little water flows over the 2nd refrigerant circuit.

    I could be all wet here. I am not sure which circuit is closest to the water pipes on this barrel. An easy check is to accurately measure the water pressure drop across the barrel. A better log sheet and more information about the unit would be helpful.

    digital gauges won't mean that you are measuring accurately. It could also mean that you are more accurately wrong. With high glide refrigerants, you need to know what the software manufacturer is using. Like I posted, if you are on the High vapor side and the software guys think you would be using the High side on Liquid only, then there could be quite a difference. I once had an analog Yellow Jacket set of gauges that had the Liquid and vapor dials printed in reverse.
    Don't step on my favorite part of the Constitution just to point out your favorite part.

    Political Correctness is forced on you because you have forgotten decency.

  13. #11
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    The circuit I change over is closest to the water inlet and I have relabled the unit to prevent cross contamination. Thank you for the explanation of the plates that makes sense. I am having trouble getting and data from the Trane 360 site for more info but I did get barrel info from the maker. 100 ton barrel 54_44 water temp drop across barrel 239 gpm 6.1 pressure drop across circuit. I didn't get tech info till I left site but flow rate is fine and don't have taps for pressures for either water or refrigerant. If I could post a pic of what it's doing I would.

  14. #12
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    Did this run well before the conversion?
    -----Stop, step back, relax and have another go at it.-----

  15. #13
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    I just took over this property from a company that like to get they're fingers wet then walk I've had to do alot of repairs to get it to run again. Was told by owner that circuit one had been freezing for a few years. But I had found the bad power head only freezing just the inlet not the suction line as well. So to answer you question yes problem was there before conversion.

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