Page 1 of 2 12 LastLast
Results 1 to 13 of 23
  1. #1
    Join Date
    Jul 2004
    Location
    Bennettsville, SC
    Posts
    248
    sorry to post another walk-in cooler problem here,but hoping for some help here...
    keep in mind i mostly do residential work

    outdoor condensing unit:copeland model#F3AH-A100-CAV-001
    indoor evap. unit:BOHN model#adt070ak
    indoor txv:Sporlan KT 43 VC
    76.4 F outdoor temp
    38 F inside cooler temp
    suction pressure:49 psi head pressure:200 psi
    suction saturation temp:25 head saturation temp:100
    suction line temp:47.3 head line temp:91.4
    **unit uses a thermostat set at 36 F**
    problem is, as you can tell the superheat is way high and over a period of a week the indoor coil is frozen up solid. I've tried adjusting the txv in both directions from factory settings and the best I can achieve is 20-22 superheat. Tried to adjust it by adding and taking away freon (oh yea i forgot to mention it's a R-22 system), finaly got frustrated and recovered all freon from system and recharged until site glass just was clear and then tried to adjust the superheat yet again by the txv with the same results. Any help with this situation would be greatly appreciated. If I have left out any needed info. please let me know.

  2. #2
    Join Date
    Jan 2004
    Location
    Earth
    Posts
    4,879
    You gave us the powerhead of the valve but not the size. Sounds like it may be to small, or your strainer is clogging. Is the valve body icing?
    A Diamond is just a piece of coal, that made good under pressure!

  3. #3
    Join Date
    Jul 2004
    Location
    Bennettsville, SC
    Posts
    248
    srry...should have wrote it like this
    BOHN (heatcraft) model #ADT070AK

  4. #4
    Join Date
    Jul 2004
    Location
    Bennettsville, SC
    Posts
    248
    no the valve body is not icing. i start seeing frost at the distributer and the first 2 loops of the evaporator.

    it doesnt seem to go any further while im there, but if i come back in a few days its frosted at least the whole coil and frozen up solid within a week

  5. #5
    Join Date
    Jan 2004
    Location
    Earth
    Posts
    4,879
    That’s the coil size, what’s the valve size (Tonnage).
    A Diamond is just a piece of coal, that made good under pressure!

  6. #6
    Join Date
    Jul 2004
    Location
    Bennettsville, SC
    Posts
    248
    not sure...we didnt install the unit and the #'s i gave are the only ones i could find on the valve...is there another way to tell?¿?¿

  7. #7
    Join Date
    Jan 2004
    Location
    Earth
    Posts
    4,879
    If its not on the powerhead, it should be stamped on the valve body. If it's a Q body there may be a silver tag on the cap tube.
    A Diamond is just a piece of coal, that made good under pressure!

  8. #8
    Join Date
    Jul 2004
    Location
    Bennettsville, SC
    Posts
    248
    the valve is in a position that is very easy to see all sides of it and there are no other visible #'s on it or around it and there is no trace of any silver tags

  9. #9
    Join Date
    Oct 2002
    Location
    Hamden Ohio
    Posts
    249
    Where are you reading your suction line temperature and your pressure reading. You should have 6°to 10°superheat at the expansion valve bulb but if you are reading the suction line temp at the compressor copelands recommendation is 20° at the compressor

  10. #10
    Join Date
    Jul 2004
    Location
    Bennettsville, SC
    Posts
    248
    i was told 12 degrees at the compressor by our supplier, but i suppose they may be wrong...were did you find ur info at¿

  11. #11
    Join Date
    Aug 2004
    Location
    Des Moines, IA
    Posts
    76

    R-22 Walk in

    40 degree suction line temop at compressor, or max of 240 degree? within 6 inches of discharge. Hermetic or semi? 12degree superheat at txv, possibly down to 4 degree depending on line length. add for pressure drop. Sporlan and alco will be stamped with tonage. Recommend, Depending on location of stat bulb, running box too cold. Insall a stat that read evap temp,say 37 degree constant cut in with specific differincial or install a time clock to shut down system for 1 to 11/2 hour each night.

  12. #12
    Join Date
    Aug 2004
    Location
    Des Moines, IA
    Posts
    76

    Hmm

    I'm new so a response would be appreciated

  13. #13
    Join Date
    Jul 2002
    Location
    hamilton ont can
    Posts
    109
    take out tstat and replace with lo press control. set it at 37#to 40# cut in and about 61# cut outto start. then measure box temp to fine tune press control. be sure to set cut in high enough to defrost coil. this takes some time but it works. i have done this many times with great sucess

    good luck

Page 1 of 2 12 LastLast

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