Results 1 to 8 of 8
  1. #1
    Join Date
    Aug 2014
    Posts
    154
    Post Likes

    need to correct temp on meat display

    hello I will be replacing deforst timer on a meat display refrigerator R134A,the case doesnt have fans only 2 evap coils top & bottom, i have set the pressure control to 40psi & differatial to 27psi,going off by pressure temp this the correct range for meat display for the product,but the customer says that the temp in the case reads 54°,any suggestion would help to maintain correct temp in the case, am new to refrigeration I mainly do hvac but to learn I have to work on them, so please dont criticize me for sounding rockie.

  2. #2
    Join Date
    Oct 2011
    Location
    Chicagoland Area
    Posts
    6,656
    Post Likes
    Don't measure the air temp. Put a thermometer in a cup of water inside the case. Return the next morning and check the water temp. Adjust you control based on the water temperature.
    Officially, Down for the count

    YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

    I know enough to know, I don't know enough
    Liberalism-Ideas so good they mandate them

  3. Likes crazzycajun liked this post
  4. #3
    Join Date
    Dec 2014
    Posts
    2,119
    Post Likes
    I'm thinking that it's more like 10, 11, or 12 , cut-out and high twenties for cut in. (PSI) And then you'll have one long defrost , say 1.5 hours, if it's the deli type case I'm thinking of.

    Sent from my SM-G930V using Tapatalk

  5. #4
    Join Date
    Aug 2014
    Posts
    154
    Post Likes
    Thread Starter
    will follow your instructions thanks

  6. #5
    Join Date
    Oct 2011
    Location
    Chicagoland Area
    Posts
    6,656
    Post Likes
    Quote Originally Posted by nytech28 View Post
    will follow your instructions thanks
    Do you understand why? Following instructions for the sake of following instructions will not make you a better tech.
    Officially, Down for the count

    YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

    I know enough to know, I don't know enough
    Liberalism-Ideas so good they mandate them

  7. Likes icemeister liked this post
  8. #6
    Join Date
    Dec 2014
    Posts
    2,119
    Post Likes
    Also, is it self-contained or remoted? If remoted its nice to have a suction stop solenoid rather than pumpdown. Pumpdown will freeze the frost hard on the coil, and its tough to thaw that on gravity coils.
    Mine build some ice during the day, but at night, when the product is covered, it has its long defrost. Then if there's any dripping, it doesn't land on the product.
    Sometimes they have to get used to seeing the ice, but it'll work.
    I generally have the stat sensor in the coil but you're using p-switch so no biggy there.
    As 2sac said. They should temp the product. Or water, glycerin, something like that. At least a large mass thermometer.

    Sent from my SM-G930V using Tapatalk

  9. #7
    Join Date
    Aug 2002
    Location
    Southold, NY
    Posts
    17,634
    Post Likes
    We need make and model #’s

    Depending on the case store humidity must be below 75% and 75*F

    Most cases look for 28* discharge air but that’s a general #

    16 CI
    11-14 CO

  10. #8
    Join Date
    Aug 2014
    Posts
    154
    Post Likes
    Thread Starter
    your rite, but working first time on refrigeration system isn't bad idea to learn from other techs.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.