Results 1 to 9 of 9
  1. #1
    Join Date
    Feb 2006
    Location
    SouthEastern Virginia
    Posts
    1,075

    York Chiller Program changed by itself

    I have a YSCABBS1-CGA with a soft starter and Eeprom chip S.01F.21. For some strange reason the chiller was capacity limited because the FLA setting changed from 421 to 288. This has happened a couple of times in the last week and I'm concerned that the micro is on it's way to the grave. Any thoughts or shared experience will be very much appreciated.
    It might get loud!

  2. #2
    Join Date
    Mar 2008
    Posts
    103

    York Chiller Program changed by itself

    duke of earl
    Have had the same thing. All data being sent from SSS goes back to default settings. Had chillers start tripping on High Motor Current, go in and find FLA setting changed. Make sure you have good grounding between the SSS, Micropanel and chiller shell. Scrape away paint at points of contact with the panels to the support brackets, "external" star washers on bolts, ferrite beads (doughnuts) around comm wire between panels. The communications between the two boards (Microboard and SSS Logic board) is susceptible to "noise" , voltage spikes.

  3. #3
    Join Date
    Feb 2006
    Location
    SouthEastern Virginia
    Posts
    1,075
    b-man,

    Thanks for the reply. What is strange is that the factory FLA setpoint was 421. At some point someone lowered the FLA because of reasons unknown. We took over the contract less than 2 years ago and found it set up this way. We made many corrections to the system and it has run real good for the exception of this problem and the lack of a tower bypass(coming soon).I will check what you said and hopefully your advice will aid in resolving the issue. Thanks again.
    It might get loud!

  4. #4
    Join Date
    Mar 2008
    Posts
    103

    York Chiller Program changed by itself

    duke of earl
    Default setpoint is not what is the factory FLA setpoint, if I understand your comment. Default is what is in before a board has ever been set up for a particular chiller. Just want to make sure we are both on the same page.
    b-man

  5. #5
    Join Date
    Mar 2007
    Location
    Melbourne,Aus
    Posts
    346
    Had Carrier high levels on 19XRV (VSD) chillers and the high level side (BACnet/Modbus&LON) have noise/no comms only when the chiller is running.....must be a bad earthing issue or some thing!!!!!!! remove the HLI from the chiller & all is Ok. Put the HLI in your cabinet and run comms out to the chiller....VSD's can cause heeps of crap.....durty voltage.....anyway..my experience !!!!!!! There has got to be noise on the comms or a bad power supply !!!! VSD's have bad power!!!!

  6. #6
    Join Date
    Feb 2006
    Location
    SouthEastern Virginia
    Posts
    1,075
    b-man,
    I smell what your'e stepping in. I wasn't aware of that. Thanks.

    Ausccn,

    I'm with you on the poor grounding. Next time I get a chance to go back I will check it out. Thanks fellas for the info.Much abliged.
    It might get loud!

  7. #7
    Join Date
    Aug 2002
    Location
    Southold.calm
    Posts
    4,856
    Duke

    One thing I’ve been taught is to ground / earth only one side of com wires, not both.

  8. #8
    Join Date
    Oct 2006
    Location
    Hampton roads VA
    Posts
    51

    York gone LOCO

    Had this happen to a york screw we had, Set FLA to 421 and chiller would allow slide valve to load chiller 100% ran chiller through it paces no problems got a call several weeks later that loop temp would olny pull down to 75Deg arrived on site on found it back at 288 Fla and not allowing chiller to load over 20% Changed main board and problem went away.

  9. #9
    Join Date
    Feb 2006
    Location
    SouthEastern Virginia
    Posts
    1,075
    thanks for the replies.
    It might get loud!

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