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  1. #1
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    York 350 ton chiller

    New to the commercial side but need some info, Company I work for just had a compressor replaced on a York screw drive chiller. The york controller has a 2 minute delay after metasys commands start but after the compressor starts there is a 30 minute count down if the compressor should shut down for any reason it will not try a restart until the countdown ends. After the 30 minute delay it reverts back to the 2 minute delay if it shuts down WHY? If its for anti short cycling I would think it would have a longer delay then 2 minutes between off command and restart what difference would a 30 minute run time do

  2. #2
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    Mixing oil and fire with a big spoon.
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    What model?

  3. #3
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    Dec 2014
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    That is part of prestart , waiting for flow , time for slide valve to zero out . If unit had a oil pump this would be prelube.

  4. #4
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    Yep, 30 minutes (usually from start to start) is to limit short cycling and two minutes is for pre-start sequence.

  5. #5
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    Quote Originally Posted by Nuclrchiller View Post
    Yep, 30 minutes (usually from start to start) is to limit short cycling and two minutes is for pre-start sequence.
    x2

    2 mins is for presetting the variable orifice.

    30 mins is anti-recycle

  6. #6
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    Quote Originally Posted by Sicofthis View Post
    x2

    2 mins is for presetting the variable orifice.

    30 mins is anti-recycle
    Really? A variable orifice valve on a screw chiller? I don't think so.

    The 2 minute lock-out is post shutdown, not pre-start. The pre-start is 30 seconds.

    To the original poster...it would behoove you to get a copy of York Form 160.47-O1 and read it. The question you asked is explained on page 7. The manual is available on JCI's website. Do a little digging you'll find it.

  7. #7
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    Quote Originally Posted by KnewYork View Post

    ...The 2 minute lock-out is post shutdown, not pre-start. The pre-start is 30 seconds...
    I stand corrected.
    Thanks, KnewYork.

    I think the conversation about two timers (and not a third), and how they relate to starting, is what threw me off. Not trying to make excuses, just trying to.... Aw heck! who am I trying to kid? Dang it. What I get for trying to jump in before Jay.

  8. #8
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    The 30 minute post-start interval is to prevent the drive motor from overheating / allow the refrigeration system's operation to dissipate the heat in the windings after a start. Many motors are only rated for a certain number of starts per hour. Usually 2 or 3 in my experience.

    PHM
    ------


    Quote Originally Posted by jnaas2 View Post
    New to the commercial side but need some info, Company I work for just had a compressor replaced on a York screw drive chiller. The york controller has a 2 minute delay after metasys commands start but after the compressor starts there is a 30 minute count down if the compressor should shut down for any reason it will not try a restart until the countdown ends. After the 30 minute delay it reverts back to the 2 minute delay if it shuts down WHY? If its for anti short cycling I would think it would have a longer delay then 2 minutes between off command and restart what difference would a 30 minute run time do
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  9. #9
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    Quote Originally Posted by KnewYork View Post
    Really? A variable orifice valve on a screw chiller? I don't think so.

    The 2 minute lock-out is post shutdown, not pre-start. The pre-start is 30 seconds.

    To the original poster...it would behoove you to get a copy of York Form 160.47-O1 and read it. The question you asked is explained on page 7. The manual is available on JCI's website. Do a little digging you'll find it.









    Start sequence is 30 secs to 2 mins depending on variable orifice actuator speed.

  10. #10
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    Apr 2014
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    Thanks for the info gentleman and knewyork ill look that up, Going to Johnson control next week for a little training, cant wait

  11. #11
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    Sicofthis...you are correct if the chiller is a style E. I made the asumption that it was an older style. However, the 2 min. lockout is still a shutdown function not a pre start function.

  12. #12
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    Quote Originally Posted by KnewYork View Post
    Sicofthis...you are correct if the chiller is a style E. I made the asumption that it was an older style. However, the 2 min. lockout is still a shutdown function not a pre start function.
    agree to disagree


    1) start command sent
    2) preparing to start in *** secs displayed (or something similar)

    *** secs is valve preset time 30 to 120 secs


    too low a preset time will nuisance trip on low oil differential 3 mins after startup expecially with cold condenser water. Too long can trip low evap.

  13. #13
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    Dec 2014
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    If you go back to single line micro panel of the late 1990 on a YS chiller a two minute timer starts , press stau


    Sent from my iPhone using Tapatalk

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