Air Curtain
Results 1 to 8 of 8

Thread: Air Curtain

  1. #1
    Join Date
    May 2002
    Location
    NJ
    Posts
    8

    Confused Air Curtain

    I am an AC guy trying to help out a customer...
    TX valve frosting up right after system is turned on. I was told the tx valve was replaced. I did not check superheat or sub cooling. The sight glass is clear. The temp in the box is high and it will freeze up the coil after running for a few days. blockage in valve?? It is freezeing from valve back to evaporator coil...moisture??

  2. #2
    Join Date
    Apr 2002
    Location
    most of the time in the Philippines
    Posts
    1,211
    Go back to square one and get a full set of diagnostic numbers [refrigerant type, type of temperature control, evaporating temp, condensing temp, superheat, subcooling, ambient temp, box temp, TXV part number, compressor model number and so on]. Would you want your doctor to feel your pulse then diagnos cancer?

  3. #3
    Join Date
    May 2002
    Location
    NJ
    Posts
    8
    I am going in tomorrow...I will get the info

  4. #4
    Join Date
    Sep 2007
    Location
    State College, PA
    Posts
    986
    Quote Originally Posted by gus6863 View Post
    I am an AC guy trying to help out a customer...
    TX valve frosting up right after system is turned on. I was told the tx valve was replaced. I did not check superheat or sub cooling. The sight glass is clear. The temp in the box is high and it will freeze up the coil after running for a few days. blockage in valve?? It is freezeing from valve back to evaporator coil...moisture??
    Clear sight glass or empty sight glass? No liquid to TXV?
    Can someone please explain to me -
    Why is there never enough time to do it right the first time, but plenty of time to do it twice?


    Please view site rules: http://hvac-talk.com/vbb/showthread.php?t=1241

    Apply for Pro Membership: http://hvac-talk.com/vbb/showthread.php?t=116113

    Find your local HVAC-Talk Contractor: http://icemeister.net/aop_map.html

  5. #5
    Join Date
    May 2002
    Location
    NJ
    Posts
    8
    full site glass

  6. #6
    Join Date
    Jul 2000
    Location
    Guayaquil EC
    Posts
    10,247
    It would be helpful to have the model number of the case...or whatever it is...you're looking at. The term "Air Curtain" doesn't do much to describe it.

    Is it an open case, glass door reach-in case, a walk-in box...?

    Regardless of what it is however, you still need to determine if the TXV is doing what it's designed to do...control the superheat leaving the evaporator. Get the info you need to diagnose that first.

  7. #7
    Join Date
    May 2002
    Location
    NJ
    Posts
    8
    ok I have more info;

    Air screen made by Regal Pinnacle
    M#SCAS48R Remote
    S#06051774
    R 404A
    Condenser
    Omni temp (Multi-unit)
    M# WD4-AC-V-10-3
    S#4930-D05
    Copeland compressor
    M#RS55C1E-CAV-201
    S#04H19358D
    uses a thermostat to close a solenoid valve and pump down
    SC was 6 then up to 10 and back to 6
    SH was 10 at condensing unit
    13# suction
    224# Discharge (taken at reciever)
    Ambient temp around condenser was 80
    box temp around 53
    unit frost up at discharge of expansion valve as soon as it turns on. It freezes to coil and the external equalizing line freezes also.
    Box was holding about 43 when I got there this am, but the coil had the back row frozzen. I defrosted it and these are the numbers

  8. #8
    Join Date
    Jul 2000
    Location
    Guayaquil EC
    Posts
    10,247
    Quote Originally Posted by gus6863 View Post
    ok I have more info;

    Air screen made by Regal Pinnacle
    M#SCAS48R Remote
    S#06051774
    R 404A
    Condenser
    Omni temp (Multi-unit)
    M# WD4-AC-V-10-3
    S#4930-D05
    Copeland compressor
    M#RS55C1E-CAV-201
    S#04H19358D
    uses a thermostat to close a solenoid valve and pump down
    SC was 6 then up to 10 and back to 6
    SH was 10 at condensing unit
    13# suction

    224# Discharge (taken at reciever)
    Ambient temp around condenser was 80
    box temp around 53
    unit frost up at discharge of expansion valve as soon as it turns on. It freezes to coil and the external equalizing line freezes also.
    Box was holding about 43 when I got there this am, but the coil had the back row frozzen. I defrosted it and these are the numbers
    The expansion valve should never have frost on the external equalizer line. That valve is toast and needs to be replaced.

    The low superheat you got at the compressor was mostly due to the flooding from the equalizer, not from the evaporator...which isn't doing anything because it's starved. This case should be running at about a 20 Deg F evap or around 55 psig.

    Here the manual for this case:
    http://50.22.131.158/~rpi/home/wp-co...II-Manual1.pdf

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event