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  1. #14
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    so what do they use ball valves for isolation?
    Sig removed by mod. G-Rated site

  2. #15
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    Jun 2006
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    Quote Originally Posted by MikeySq View Post
    so what do they use ball valves for isolation?

    The only one I've worked on had standard service valves at each compressor.

  3. #16
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    I'm confused now... haha I've only seen scroll compressors with braze ends with no valves or with roto-lock connected service valves. Just curious what would those standard valves be like??
    Sig removed by mod. G-Rated site

  4. #17
    I have been using this system for a while. If the system is installed correctly the system will save money over normal system, it uses less freon than most units. It cost less to operate. We use them in Aldi and they love the systems

  5. #18
    Join Date
    Nov 2009
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    386
    Quote Originally Posted by MikeySq View Post
    do you mean there's protocols with braze in compressors? that's dumb

    Got one out there now with 2 suction groups, the #1 comp on the MT side is way too much for low load situation and bangs on and off like crazy, It runs all the time now so the problem is not really fixed, but the suction pressure is a bit lower than it's design

    Mike
    I have many of these with the same low load issue. Would you elaborate on what you have done to shorten the cycles and smooth out the suction? I would appriciate any successes that any of you have had on this issue.

    We have a lot of customers installing protocols with the fixtures all being controlled by suction stop. The load varies greatly all the time and the suction and compressor cycles are all over the road. I have been raising the suction target and insuring that all the fixtures are set at spec for longer system run times and to reduce the suction stop cycles. I have also been playing with the suction setpoint differential, etc (Enhanced suction).
    Some success but still looking for input from anyone.

    I also have many that are using Comtrol. This is proving to be even more of a challenge as the 4k/4k2 is not as flexible as the E2

    I thought if installing a digital scroll but the customer is opposed to using them..... UGH!
    "Don't wish it were easier, wish you were better"

  6. #19
    Join Date
    Jun 2006
    Location
    Omaha, Nebraska
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    869
    ^ The 4K is now obsolete. Maybe a good time to upgrade to E2. As far as improving control, it's best to have a good range of sizes, such as a small 5 HP compressor, a 10, and several larger ones so that there can always be a combination of pumps running that come close to matching your load. I also find it helpful to stagger defrosts so that you don't have a bunch of cases with no load all at the same time.

    Finally, you might consider using SORIT valves instead of suction stops. That way the case is always "on" except in defrost. It evens out the load considerably. I've also had issues with floodback after defrost with the suction stops. Not sure why.

  7. #20
    Join Date
    Nov 2009
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    386
    Quote Originally Posted by man from trane View Post
    ^ The 4K is now obsolete. Maybe a good time to upgrade to E2. As far as improving control, it's best to have a good range of sizes, such as a small 5 HP compressor, a 10, and several larger ones so that there can always be a combination of pumps running that come close to matching your load. I also find it helpful to stagger defrosts so that you don't have a bunch of cases with no load all at the same time.

    Finally, you might consider using SORIT valves instead of suction stops. That way the case is always "on" except in defrost. It evens out the load considerably. I've also had issues with floodback after defrost with the suction stops. Not sure why.
    Thanks for the comment!

    Our customer that uses Comtrol has chosen to use Danfoss when an overlay is needed. I was hoping they would choose E2.

    However, another one of our customers using protocol is using E2. But all systems are suction stop like I mentioned. This comes down from corporate engineering. Nothing I can do about that, they will not allow us to go in and use SORIT. I agree with you, that would make a big difference. To this customer, if it won't save energy, and a lot of it, they won't do it. They use this logic on being resistant to digital scroll.

    As far as compressor sizes, I am lucky if the lead compressor is smaller. Most times they are all the same.

    With all that, I am having to try to come to a adequate solution with what the customer has given me to work with. Double
    "Don't wish it were easier, wish you were better"

  8. #21
    Join Date
    Jun 2006
    Location
    Omaha, Nebraska
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    Then pretty much all you can do is change your sensitivity number to lengthen the compressor cycles.

  9. #22
    makes no sense

  10. #23
    Join Date
    Nov 2009
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    386
    Quote Originally Posted by Oasis Services View Post
    makes no sense
    What are you talking about???
    "Don't wish it were easier, wish you were better"

  11. #24
    Join Date
    Jun 2006
    Location
    Omaha, Nebraska
    Posts
    869
    I've only seen one digital scroll down here, on a Kyser-Warren rack. But the controller for it was defective at startup so I never got to see it in action. It will be months before they get a new controller here. I can't wait to get back to the states and civilization! (oh, I forgot. I changed my location on this site to Omaha but I've still got another 10 days to go here in the Caribbean.)

  12. #25
    Join Date
    Dec 2011
    Location
    USA
    Posts
    66
    We have quit a few protocols with electronic controls they are very reliable. The short cycling normally comes from being oversized. They are not too bad to work on if you can get around them, all the panels come off.

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