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  1. #14
    Join Date
    Apr 2009
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    Deerfield Beach, FL, which is a northern suburb of Fort Lauderdale.
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    22
    Thank you, sir, you've saved Algernon a bunch of time.

  2. #15
    Join Date
    Sep 2008
    Location
    Western PA
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    25,682
    Quote Originally Posted by guilbertj2006 View Post
    The dispatcher, she asked for receiver liquid-levels on the racks both with and without Heat Reclaim. The dispatcher likes to give scolding lectures, too, so since all I've seen in the stores is hot water reclaim off the racks, I'll just keep an eye peeled on the blueprints HVAC/Refrigeration mechanical plans pages, whenever I'm not performing my normal duties of 'covering all the bases' (and selling popcorn in the stands). But any insight you have is always welcome.
    Your dispatcher is right.

    With water reclaim, this isn't typically a big issue.

    If, however, the store has air heat reclaim coils, it can require a bit of additional refrigerant to fill that coil.

    While water reclaim is a desuperheating process, air reclaim tends to both desuperheat and partially saturate the refrigerant.

    I have one store in particular that requires almost 200# to fill the reclaim coil.

    When we log refrigerant levels, we log the level, ambient temperature, split condenser and heat reclaim status. With stores that have EMS systems, we take an average reading from the EMS system in addition to a spot reading.

  3. #16
    Join Date
    Dec 2004
    Posts
    509
    Quote Originally Posted by guilbertj2006 View Post
    I'm looking to understand better South Florida Supermarket (Publix) Heat Reclaim. There are valves in the drop leg, of course, but we don't have the low ambient issues. I see the water tanks run 120F on 90-95F OAT. Are the water tanks supposed to only de-superheat the refrigerant? or do they saturate the refrigerant, too; and is there liquid/vapor feeding back into the condenser. Also, what other, alternately, heat sinks are there for Publix Heat Reclaim. Any link on their protocol, how the system is set up, or just firsthand information, would be helpful. Thankyou in advance.
    Trying to understand your question here, I use to service publix a few years back. Yes they use a reheat coil to control store humidity. Unless they have changed their design.

    They generally like hill racks and break it up into multiple racks in multiple houses although they did have a few stores with just 2 racks. Either case typically they use the med temp rack 4 water reclaim and subcooling on low temp rack, low temp rack 4 air reheat.

    Typically what I seen them using is a 3way valve off the discharge line that diverts the discharge gas to the reclaim coil then dumps back into to inlet side of the condenser. It is piped in series not in parallel as you are describing.

    What I think you may be looking at is a schooling bypass that is designed to bypass the receiver during low ambient conditions. I could be wrong on this point because it's been awhile that I have serviced a public and don't recall if they utilize that bypass technology. But I digress

    The 3way valve I spoke of earlier is energized by the a.c. controller not the racks and it's typically controlled off of dew point.

    That is the basic concept of publix engineering. What they do works don't try to out think them. Follow their lead and everyone will be for the better. I hope that basic overview helped you comprehend what your dealing with.


    Also your dispatcher is half right labour noting if your in or out of reclaim. Pump your rack down before recording levels. It will still fluctuate but will give you a moreaaccurate and more stable recording of refrigerant levels.

  4. #17
    Join Date
    Apr 2009
    Location
    Deerfield Beach, FL, which is a northern suburb of Fort Lauderdale.
    Posts
    22
    Quote Originally Posted by gas_n_go View Post
    Trying to understand your question here, I use to service publix a few years back. Yes they use a reheat coil to control store humidity. Unless they have changed their design.

    They generally like hill racks and break it up into multiple racks in multiple houses although they did have a few stores with just 2 racks. Either case typically they use the med temp rack 4 water reclaim and subcooling on low temp rack, low temp rack 4 air reheat.

    Typically what I seen them using is a 3way valve off the discharge line that diverts the discharge gas to the reclaim coil then dumps back into to inlet side of the condenser. It is piped in series not in parallel as you are describing.

    What I think you may be looking at is a schooling bypass that is designed to bypass the receiver during low ambient conditions. I could be wrong on this point because it's been awhile that I have serviced a public and don't recall if they utilize that bypass technology. But I digress

    The 3way valve I spoke of earlier is energized by the a.c. controller not the racks and it's typically controlled off of dew point.

    That is the basic concept of publix engineering. What they do works don't try to out think them. Follow their lead and everyone will be for the better. I hope that basic overview helped you comprehend what your dealing with.


    Also your dispatcher is half right labour noting if your in or out of reclaim. Pump your rack down before recording levels. It will still fluctuate but will give you a moreaaccurate and more stable recording of refrigerant levels.
    Very imformative, thanks for the response and the details on the Publix engineering.

  5. #18
    Join Date
    Apr 2009
    Location
    Deerfield Beach, FL, which is a northern suburb of Fort Lauderdale.
    Posts
    22
    The receivers have an analog gauge with a needle on the tank, and many of the Einstein-2 controllers give a liquid level. But I've taken readings as diparate as 50% on the E2, while the needle is pointing to 8%. So I just enter the analog reading into the Log. The routine I worked out so far, subject to change, is: liquid-level on the receiver; oil level in the individual levellers and in the separator; if the liquid-level is zero see if the sight-glass is flashing; if it is, scroll through the circuits to see if any are in HG defrost; and also the status of the lineup, if any, particularly those at the end, are in alarm. Then Heat Reclaim: I started at first by valving off the 'From HR" ball-valve, feeding back into the condenser, and then retook the level. On two racks the liquid-level dipped to zero and the compressors cycled off (at midday in S. Florida). I opened the valve back up and heard a surge, and turned a little whiter. I thought, 'jeepers, be careful.' That's a lot of power. Now I've taken to closing the 'To HR' valve, thinking that at least its 100% vapor and I won't be hammering the lines and connections with liquid. (mr. Popsicle.) A lot, I mean like at least a score, of the 22 receivers are at zero. Is that normal? while a lot of them also have 10 - 20% in them. On the racks with Hot Water Reclaim I haven't seen the needle move.

  6. #19
    Join Date
    Sep 2008
    Location
    Western PA
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    25,682
    Quote Originally Posted by guilbertj2006 View Post
    The receivers have an analog gauge with a needle on the tank, and many of the Einstein-2 controllers give a liquid level. But I've taken readings as diparate as 50% on the E2, while the needle is pointing to 8%. So I just enter the analog reading into the Log. The routine I worked out so far, subject to change, is: liquid-level on the receiver; oil level in the individual levellers and in the separator; if the liquid-level is zero see if the sight-glass is flashing; if it is, scroll through the circuits to see if any are in HG defrost; and also the status of the lineup, if any, particularly those at the end, are in alarm. Then Heat Reclaim: I started at first by valving off the 'From HR" ball-valve, feeding back into the condenser, and then retook the level. On two racks the liquid-level dipped to zero and the compressors cycled off (at midday in S. Florida). I opened the valve back up and heard a surge, and turned a little whiter. I thought, 'jeepers, be careful.' That's a lot of power. Now I've taken to closing the 'To HR' valve, thinking that at least its 100% vapor and I won't be hammering the lines and connections with liquid. (mr. Popsicle.) A lot, I mean like at least a score, of the 22 receivers are at zero. Is that normal? while a lot of them also have 10 - 20% in them. On the racks with Hot Water Reclaim I haven't seen the needle move.
    Seriously.

    stop with the valves already.

    You're going to damage something.

  7. #20
    Join Date
    Apr 2009
    Location
    Deerfield Beach, FL, which is a northern suburb of Fort Lauderdale.
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    Quote Originally Posted by jpsmith1cm View Post
    Seriously.

    stop with the valves already.

    You're going to damage something.
    A word on time-line: Dispatch told me not (in a more elevated tone than needed) to pump-down for levels a week or so before your (helpful) post, which does describe a method using pump-down to obtain accurate liquid-levels. I'm posting so that I at least know the right way to do things, even if I am directed to do them another way in order to hold onto this position. I am a professional, and aspire to remain one; I only want to increase in skill. I wasn't sold on a pump-down to begin with, because, and this is a question, Will the receiver hold the liquid? That's why I'm asking if it is normal for the (no names) R22 receivers to be at a zero liquid level, deliberately, in order to hold the gas? or this just another hot potatoe item.

  8. #21
    Join Date
    Sep 2008
    Location
    Western PA
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    25,682
    Quote Originally Posted by guilbertj2006 View Post
    A word on time-line: Dispatch told me not (in a more elevated tone than needed) to pump-down for levels a week or so before your (helpful) post, which does describe a method using pump-down to obtain accurate liquid-levels. I'm posting so that I at least know the right way to do things, even if I am directed to do them another way in order to hold onto this position. I am a professional, and aspire to remain one; I only want to increase in skill. I wasn't sold on a pump-down to begin with, because, and this is a question, Will the receiver hold the liquid? That's why I'm asking if it is normal for the (no names) R22 receivers to be at a zero liquid level, deliberately, in order to hold the gas? or this just another hot potatoe item.
    I didn't tell you to pump anything down. I told you to log the level as it was.

    Someone else told you to do that.

    The receiver should hold a minimum charge. I like to see 20-30% at all times. 0% is a red flag.

  9. #22
    Join Date
    Feb 2008
    Location
    California
    Posts
    2,066
    Quote Originally Posted by guilbertj2006 View Post
    I started at first by valving off the 'From HR" ball-valve, feeding back into the condenser, and then retook the level. On two racks the liquid-level dipped to zero and the compressors cycled off (at midday in S. Florida). I opened the valve back up and heard a surge, and turned a little whiter. I thought, 'jeepers, be careful.' That's a lot of power. Now I've taken to closing the 'To HR' valve, thinking that at least its 100% vapor and I won't be hammering the lines and connections with liquid. (mr. Popsicle.) A lot, I mean like at least a score, of the 22 receivers are at zero. Is that normal? while a lot of them also have 10 - 20% in them. On the racks with Hot Water Reclaim I haven't seen the needle move.
    In either case, you are essentially closing the discharge line off on a running rack in heat reclaim mode...VERY dangerous!

    When checking receiver levels...

    Heat Reclaim ON
    No systems in defrost
    Note head pressure
    Note ambient temperature
    Note receiver level

    10% level is sufficient
    If you have a receiver alarm, 10% above alarm is sufficient
    If you have condenser flooding valves, possibly 40%-50% is sufficient.

    These are good points for mild climates...if your ambient gets much below 40 (I don't know how chilly Florida gets), you'll wanna see more towards 20%


  10. #23
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    Sep 2008
    Location
    Western PA
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    Quote Originally Posted by Phase Loss View Post

    In either case, you are essentially closing the discharge line off on a running rack in heat reclaim mode...VERY dangerous!
    Bringing us back to one of my earlier posts.

    Friend, if you're closing valves without an understanding of the consequences of doing so, you probably need to stay out of the mechanical room.

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