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  1. #1
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    YORK AIR SCREW CHILLER...ALL COMPRESSORS OUT ON LOW SUCTION

    Hey All,

    Need quick info. York Air-Cooled Screw Latitude 500ton Chiller

    I've never actually worked on a York Lat before so I'm looking for someone who's had to deal with these. Back story, These units sat crated for year+ due to construction delays and then sat additional year+ after installation prior to commissioning because of more delays. A chiller ran for 3 days before all four compressors failed on Low Suction. We test ran it again until compressors alarmed out on Low Suction to see if we good determine anything. I either have a leak (all four) or a blockage (on all four). I do not have the equipment on hand to deal with 400 lbs of R134 so I will check anything before tearing into the evap.

    Anyways, before I tell them how F'd they are on a brand new (5 year old) chiller. I want to make sure I'm not missing something that ISN'T in the troubleshooting procedures. My recommendation was to bring in a York guy to re-commission these units so they have documentation for the inevitable lawsuits.

    FYI_NO OIL SIGNS.

    Suggestions?

  2. #2
    Join Date
    Sep 2002
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    What is the flow rate through the chiller?

    PHM
    ------


    Quote Originally Posted by HDog View Post
    Hey All,

    Need quick info. York Air-Cooled Screw Latitude 500ton Chiller

    I've never actually worked on a York Lat before so I'm looking for someone who's had to deal with these. Back story, These units sat crated for year+ due to construction delays and then sat additional year+ after installation prior to commissioning because of more delays. A chiller ran for 3 days before all four compressors failed on Low Suction. We test ran it again until compressors alarmed out on Low Suction to see if we good determine anything. I either have a leak (all four) or a blockage (on all four). I do not have the equipment on hand to deal with 400 lbs of R134 so I will check anything before tearing into the evap.

    Anyways, before I tell them how F'd they are on a brand new (5 year old) chiller. I want to make sure I'm not missing something that ISN'T in the troubleshooting procedures. My recommendation was to bring in a York guy to re-commission these units so they have documentation for the inevitable lawsuits.

    FYI_NO OIL SIGNS.

    Suggestions?
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  3. #3
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    Thread Starter
    Pump under VFD but never deviates from 30% so it appears that the VFD is locked at 30%.

  4. #4
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    Thread Starter
    300GPM per pump

  5. #5
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    Aug 2002
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    Southold, NY
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    Are you a Tech or Maintenance Man on Site?

    You need 1500 GPM

  6. #6
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    Thread Starter
    Where did you come up with 1500 GPM? Do you have a link to the table that states the values? The manual I have merely states cooler GPM is MIN-400 GPM and MAX-1400 GPM.

  7. #7
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    3GPM per Ton on average.

    Your manual stated 1400. I'd say i was close

  8. #8
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    I would unlock the VFD.

    "locked at 30%" being correct for the chillers would mean that the pumps are 300% larger than they have to be - which seems very unlikely to have been specified.

    PHM
    -------


    Quote Originally Posted by HDog View Post
    Pump under VFD but never deviates from 30% so it appears that the VFD is locked at 30%.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  9. #9
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    I want to re-ask that one germaine question.... are you an HVAC technician, or are you an on-site maintenance man?
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

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  10. #10
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    Quote Originally Posted by timebuilder View Post
    I want to re-ask that one germaine question.... are you an HVAC technician, or are you an on-site maintenance man?
    Now that’s a tough one to answer.

  11. #11
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    Thread Starter
    Rule of thumb. Doesn't work correctly with VSD compressors and pumps on VFD because demand and GPMs are supposed to fluctuate.

  12. #12
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    Thread Starter
    I agree with the assumption. After I brought up the concern regarding pumps "seem to be locked at 30%" amazingly they are now fluctuating. Yes, others have access to DDC. I'm caught in the middle of a bunch of egos and insecurities.

  13. #13
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    Quote Originally Posted by pecmsg View Post
    3GPM per Ton on average.

    Your manual stated 1400. I'd say i was close
    3 GPM per ton is average for water cooled condenser. 2.4 GPM per ton is nominal for chilled water which will give you a 10 delta T At full load. Many new sites have lower flow rates and higher delta T but I agree 30% on VFD is way too low.

    Quote Originally Posted by Poodle Head Mikey View Post
    I would unlock the VFD.

    "locked at 30%" being correct for the chillers would mean that the pumps are 300% larger than they have to be - which seems very unlikely to have been specified.

    PHM
    -------
    The flow rate is not linier to speed, it’s squared so 30% = 18 HZ which means there is about 5% flow going through the chiller if the pump was sized correctly.

    Quote Originally Posted by timebuilder View Post
    I want to re-ask that one germaine question.... are you an HVAC technician, or are you an on-site maintenance man?
    You’ve been asked this question twice and seem to be dodging it. Are you a chiller tech or maintenance?
    The 2nd most important amendment is to protect the 1st...

    Free Air Conditioner Sizing Chart

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