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  1. #1
    Join Date
    Oct 2002
    Location
    Plano, TX
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    Carrier VRF- heat recovery fail

    I attended a well taught class on Carrier VRF technology and Carrier's system.

    We were told that refrigerant can only be weighed in, if you experience a leak. No gages are to be used.
    Wow, system is sold as a replacement option for Chillers in 11 story building holding upwards of 100 lbs. of refrigerant. System uses 50% more piping then conventional.

    So to repair a leak, you need to recover and weigh back in. Come on Carrier, there got to be a better way.

    My customers would not be happy with AC or heating would be off all day in a high rise building so I can repair a refrigerant leak.

  2. #2
    Join Date
    Jul 2011
    Location
    DFW, TX.
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    1,445
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    I did an install where we put King valves on the inlet and Outlet of the EVAP coil line set. So that in the event of a leak we could Bshut off that coil and not lose system charge. That being said we had leaks and I never weighed in just did it off of pressure ratings and Supply air temp

    Sent from my LG-G710 using Tapatalk
    Text to speech does not work for me currently

  3. #3
    Join Date
    Aug 2002
    Location
    Southold, NY
    Posts
    25,622
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    Like Minis you can add gas and get close enough but eventually the charge has to be pulled and weighed. With 100#'s that's shutting them down for at least a day!

  4. #4
    Join Date
    Jun 2014
    Location
    Dover, DE
    Posts
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    This isn’t isolated to Carrier.
    All VRF are critically charged. A scale must be used. If there’s a leak the charge should be pulled and weighed back in.
    I’m actually getting ready for a weekend job to do just that, for my 10 story tall Samsung DVM building. The fifth floor had a very easily repaired leak and I got the charge close by using compressor temps, discharge temps and such.
    During startups after I get the full charge in, I take my gauges off and put them in the truck. As they are pointless in the grand scheme of things.
    I havent failed. Ive just found 10,000 ways that wont work. - Thomas Edison

    Its not whether you get knocked down, its whether you get up. - Vince Lombardi

    "In this house we obey the laws of thermodynamics" - Homer Simpson

    Local 486 Instructor & Service Technician

  5. #5
    Join Date
    Jul 2019
    Location
    Oklahoma home its in the name
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    It seems like they could offer a solenoid valve that plugs into a board somewhere and allows the unit to charge itself. It really seems like those units have enough sensors to be able to do that.

    Sent from mars using Tapatalk

  6. #6
    Join Date
    Jun 2014
    Location
    Dover, DE
    Posts
    11,668
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    The unit would still have a hard time determining correct charge or not.
    Initial charging is easy. The hard part is post leak when you’ve only lost a portion of the charge and you don’t have to reclaim to fix the leak.
    I havent failed. Ive just found 10,000 ways that wont work. - Thomas Edison

    Its not whether you get knocked down, its whether you get up. - Vince Lombardi

    "In this house we obey the laws of thermodynamics" - Homer Simpson

    Local 486 Instructor & Service Technician

  7. #7
    Join Date
    Jul 2019
    Location
    Oklahoma home its in the name
    Posts
    716
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    That's too bad. It would be nice if it was possible.
    Quote Originally Posted by rider77 View Post
    The unit would still have a hard time determining correct charge or not.
    Initial charging is easy. The hard part is post leak when youve only lost a portion of the charge and you dont have to reclaim to fix the leak.
    Sent from mars using Tapatalk

  8. #8
    Join Date
    Nov 2011
    Location
    East Side
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    7,048
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    I usually go by discharge temps if I have a leak. running everything 100% for about 15 minutes, I look for 170-190*.......but that's still just guessing.

  9. Likes CEAS-AC-TECH liked this post

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