Results 1 to 8 of 8

Thread: tyler case

  1. #1
    Join Date
    Sep 2016
    Location
    Saint Johnsville NY
    Posts
    11
    Post Likes

    tyler case

    So, I know this is an old topic but i have a new customer that has a tyler case, N6DL12. had another company install the unit, in 2012. compressor died in sometime 2017. cs18k6e-pfv-945.
    when the other company replaced the compressor in 2017ish never installed new filter also has the orignal from 2012. (my habit is to change when failures occur)
    So I go today for no cooling and unit trips breaker. massive electrical failure. hard short to ground all lines. 3.4ohms to case on R, S, C,.

    so the customer needed the case up asap so we get a new compressor another cs18, install, put filters on, purge evac make sure the system is good and clean as we can. all seems well for now.

    Then i start to look at the cycle times on the unit to found a root cause, and here comes my problem.

    since 2012(i assume that the counter didnt reset) i have 262961 cycles on the unit controller. seems a little high to me.

    the OEM cond unit is a FJAM-A300-CFV-020 ( Dawned on me that his unit seems littler over sized in my head)

    so i start to look at the ratings and found this post. so i do my calcs and this is what i came up with

    Case Requirements: Conv. 1,361 Btu/ft total 16,332 btu/hr

    Cond Unit caps: Ext med temp 20* coil: 21,600

    Ranco ETC controll set to 39 with 4* (I adjusted to 38* with 7* diff to allow longer off cycles)
    Case is storing produce also

    now the unit is in a nice cool basement, year round cool also

    also the upstairs is AC so it doesnt get to hot also

    Now working on our supermarket systems, i know an oversized unit can cause issues as i am thinking thats what is causing the failures on this case. this case also appears to been removed from a rack system due to the configuration of the pipe system


    My Diag is showing that
    1st: Oversized cond unit
    2nd: excess cycle events
    3rd: Lack of cooling coming back as runtime is short. Gas return is about 60 coming back


    I would like your thoughts on to as my best course of action for this customer

  2. #2
    Join Date
    Mar 2008
    Location
    kansas
    Posts
    411
    Post Likes
    What refrigerant, txv size, have you clocked cycle times. Did you check superheat Copeland claims when a unit shorts to ground 90% of the time it’s liquid washing the bearings out (not sure I buy those numbers). Where are you sensing case temp?
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  3. #3
    Join Date
    Sep 2016
    Location
    Saint Johnsville NY
    Posts
    11
    Post Likes
    Thread Starter
    R404a
    Txv seems to be a bfse 1 1/2 ton
    Superheat at compressor is 37

    Superheat after txv is 11

    Does have a suction heat exchanger so that screws my cooling going back.

    Yea that bearing is Bologna for ground shorts.
    Case temp is at discharge at top of case which is normal for rack system cases

  4. #4
    Join Date
    Oct 2011
    Location
    Chicagoland Area
    Posts
    6,088
    Post Likes
    Did you test the system for acid?
    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

  5. #5
    Join Date
    Sep 2016
    Location
    Saint Johnsville NY
    Posts
    11
    Post Likes
    Thread Starter
    Yes and checked clear I have an oil sample also oil is slight Amber so not horribly odd. I also want to know that the smell was not normal for an r404 gas too which was odd

  6. #6
    Join Date
    Oct 2011
    Location
    Chicagoland Area
    Posts
    6,088
    Post Likes
    Quote Originally Posted by dpercival4 View Post
    Yes and checked clear I have an oil sample also oil is slight Amber so not horribly odd. I also want to know that the smell was not normal for an r404 gas too which was odd
    Did you taste it? Bad oil has a funky taste to it.
    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. #7
    Join Date
    Mar 2008
    Location
    kansas
    Posts
    411
    Post Likes
    Yes sensor in discharge is common for racks but racks don’t start and stop which could be contributing to your short cycling. Guessing the heat exchanger was added to raise sh sounds like they have had compressor issues in the past. Maybe try throttling the suction valve see is it will calm down the stops maybe an epr might be in order.
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  8. #8
    Join Date
    Sep 2016
    Location
    Saint Johnsville NY
    Posts
    11
    Post Likes
    Thread Starter
    The heat exchanger is was part of a rack system so it doesn't appear to been added after the fact
    I increased cycle time by adjusting txv to 28 * coil. Getting cooling back prior company said cond unit is to small. All my numbers shows it way oversized for a open mechandizer

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.