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  1. #1
    Join Date
    Nov 2019
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    52 pounds of refrigerant - LOST

    I'm the facilitates manager of a property in Chicago. We have a large space heated/cooled by a 48 ton system, (3 twinned 16 ton Y-series, Hyperheat Mitsubishi heat pumps).

    Last week 8 of the inside blower units were blowing cold air. Called our local service provider (who happens to be the company that installed the system.) Tech came out and contacted Mitsubishi. System was put on Maintenance Tool, and a Mitsubishi tier 2 (or tier 3?) tech determined loss of refrigerant.

    Now, this system is only 3 years old. No issues prior to last week. The tech and I both noticed this on the heat pump in question (see pics attached). Each heat pump has a pressure relief valve. Around the pressure relief valve of the heat pump in question, there are oily deposits. You can even see oil on the aluminum support frame. The other two twinned units are dry.

    We don't know for sure at this stage HOW the refrigerant was lost, but if I had to bet money, I think this is the culprit. Tech will be back next week to start some leak testing, and I suspect will find it here.

    What is everyone's thoughts? Do these valves typically fail? Can the valve be cut out and we have it tested somewhere?

    I've already called Mitsubishi about it, and the reps said, "this is not a Mitsubishi part. This is a third party part added by the installer."

    My guess is Mitsubishi will not be covering any of the work/cost since it was not a Mitsubishi part that failed. HOWEVER, I do hope we find out if the system had an over pressure incident that it caused this relief valve to open. Perhaps some other part in the system failed (thermistor? Pressure sensor?) Presumably, if the pressure reaches dangerous levels, the system would shut itself down.

    I'm not sure what these valves are rated at, but I found similar ones that are rated at 700 pounds.

    Other question, are these pressure relief valves required in Chicago? That's where I'm located.

    Thanks
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  2. #2
    Join Date
    Sep 2007
    Location
    edmonds wa
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    Does have oil staining on the piping end and under it. Get the electronic sniffer out.
    UA Local 32

  3. #3
    Join Date
    Oct 2012
    Location
    Los Angeles, CA, USA
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    Put a rubber, disposable style glove around it and tape tightly. If there is a leak the glove will inflate. Condoms also work, but the aesthetics are questionable according to some.

  4. #4
    Join Date
    Aug 2002
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    Southold, NY
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    Do components fail....Yes
    Blame Mitisubishi NO

    Something else happened.

    Do you have a start up and commissioning report?

  5. #5
    Join Date
    Jan 2010
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    Sea to Sky
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    Looks field installed and not Mitsubishi to me....apparently Chicago has some stringent regs..

    I am sure someone who works in the area will see this thread...

    @2sac

    Sent from my SM-G965W using Tapatalk

  6. #6
    Join Date
    Jan 2010
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    I was informed by a reliable source that in Chicago, any equipment with over 5lbs of refrigerant requires a pressure relief.

    Sent from my SM-G965W using Tapatalk

  7. #7
    Join Date
    Aug 2002
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    Southold, NY
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    The mechanical code requires pressure relief's piped to the outside of the building. What's the rating on those?

  8. #8
    Join Date
    Oct 2016
    Location
    Clearwater, Florida
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    What makes you think that's the culprit?

    Because it's visible?

  9. #9
    Join Date
    Sep 2007
    Location
    edmonds wa
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    Well if you look at the first pic you will see oil stain on the end of the copper, on the end of support leg and on the ground all in the vicinity of the discharge pipe. That is where i would start and take off the flare nut and inspect for oil, should be dry.
    UA Local 32

  10. #10
    Join Date
    Nov 2019
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    Thread Starter
    Sorry for the silence, long story short, the pressure relief valve was either faulty or tripped due to a high pressure incident.


  11. #11
    Join Date
    Aug 2002
    Location
    Southold, NY
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    Quote Originally Posted by gpier View Post
    Sorry for the silence, long story short, the pressure relief valve was either faulty or tripped due to a high pressure incident.

    Was that there explanation? I would want to know what one! If its faulty a simple pressure test will determine, if it did its job they had better find out why.

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