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  1. #14
    Join Date
    Sep 2002
    Posts
    12,280

    I guess I have to go there back now <g>

    I have been puzzling over my notes - scribbled from memory after the fact as the job was a rain-out at the end - and now I'm not even sure whether they came from this 407 job or not! <g> The more I think about it the more confused I get. So I guess I have to run back over there - I'll explain it a a gesture of good will: just want to make sure everything is perfect for you. <g>

    I won't bother mentioning the real reasons. <g>

    PHM
    ---------




    Quote Originally Posted by Poodle Head Mikey View Post
    Customer had/has a leaking evap - would not replace a month ago.
    Customer had a compressor fail - would not replace evap now.
    I installed an R407 condenser and a huge LL drier

    This is the result:

    Outdoor Ambient 82
    Indoor Ambient 82
    Head press 180 lbs = bubble point 85
    Suction press 75 lbs - dew point 38
    LL temp 72
    Subcooling = 13
    Suc temp 66
    SSH = 28
    Evap air TD - 82-65 = 17

    How does it look to you?
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  2. #15
    Join Date
    Sep 2002
    Location
    Virginia
    Posts
    3,163
    I still have not frankensteined my 5 ton unit from couple weeks ago .... i might do what you did depending on your outcome.

    Did you choose a chinese cond ?

    ps .... my evap has no leaks

  3. #16
    Join Date
    Sep 2002
    Posts
    12,280
    I used a Thermal Zone - made by Rheem they tell me. And after seeing the unit inside and out - if Rheem didn't build it; whoever did made a perfectly replicated job out of it. <g>

    I have forgotten already - what was the frankenstein-ing of your five ton to consist of?

    I must have goofed up the start-up numbers in some way as the extremely-picky engineer customer seems thrilled with the system's performance and called me to say so.

    PHM
    -------




    Quote Originally Posted by Snapperhead View Post
    I still have not frankensteined my 5 ton unit from couple weeks ago .... i might do what you did depending on your outcome.

    Did you choose a chinese cond ?

    ps .... my evap has no leaks
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  4. #17
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,907
    Quote Originally Posted by Poodle Head Mikey View Post
    Apparently so. My test gear is accurate.

    Why do you ask?

    PHM
    -------
    Cause generally that would indicate a restriction before the schrader valve, or where you have your temp probe.

    Same thing if you had an R22 system, you wouldn't want or expect your LL temp to be below outdoor temp.
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  5. #18
    Join Date
    Sep 2002
    Posts
    12,280

    Oh! I forgot the best part !

    During the project the engineer customer is with me constantly and endlessly either asking questions or telling me things. Plus; we are trading engineering stories of all kinds, discussing higher education, philosophy, and various languages.

    At some point I get it all together and looking nice so I dump in some refrigerant and fire it up. I notice immediately that the condenser fan is making a sort of clicking noise. So I look at that and ponder/project just what the problem might be. Immediately the guy starts:

    What's the matter? Is something wrong? What could it be? Why would there be a problem? (and on and on until I want to bellow Shut The Fuk Up! - but don't because I am too gracious)

    I'm tired, it's hot, he has managed to stand in front of my fan all day, and the yammering is bugging the hell out of me. So I listen and realize that it's the compressor - not the fan making the noise. It sort of sounds somewhat like a scroll running backwards - but this is single phase so it's not that.

    So then I get him to be quiet and I am frenziedly scanning through the data banks: How can this be? What is that noise? What can cause this?

    About then I notice that the gauge pressures are almost exactly the same. What??? A brand new compressor isn't pumping? How the hell can that be?

    So I shut it off again and pause and ponder and go over the details of the install again in my head: running the mental video.

    It was just about then that I realized that I had neglected to open the service valves on the unit. <g>

    I laughed and leaped to do that - of course immediately contaminating the R407 with whatever non-condensible the dry pressure charge is. <g>

    In the end I did manage to get away without drowning - but just Barely. <g>
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  6. #19
    Join Date
    Sep 2010
    Location
    Lake Ronkonkoma, New York
    Posts
    535
    Quote Originally Posted by MontanaJon View Post
    According to my 407c pt chart your vapor pressure temp should be 48 instead of 38. Either yor sh math is wrong or mistype for sp/temp. 3 over ambient with 13 sc. That's got to be the best refrigerant for heat exchange ever...lol
    Just did a quick calculation I learned in diagnostics class which is 82 degree return temp - 35 which equals 47 degree evaporator saturation temp. Very close to your number MontanaJon.
    If the women don't find you handsome, they should at least find you handy.

  7. #20
    Join Date
    Jun 2009
    Location
    Ontario, Canada
    Posts
    1,029
    Quote Originally Posted by Poodle Head Mikey View Post
    During the project the engineer customer is with me constantly and endlessly either asking questions or telling me things. Plus; we are trading engineering stories of all kinds, discussing higher education, philosophy, and various languages.

    At some point I get it all together and looking nice so I dump in some refrigerant and fire it up. I notice immediately that the condenser fan is making a sort of clicking noise. So I look at that and ponder/project just what the problem might be. Immediately the guy starts:

    What's the matter? Is something wrong? What could it be? Why would there be a problem? (and on and on until I want to bellow Shut The Fuk Up! - but don't because I am too gracious)

    I'm tired, it's hot, he has managed to stand in front of my fan all day, and the yammering is bugging the hell out of me. So I listen and realize that it's the compressor - not the fan making the noise. It sort of sounds somewhat like a scroll running backwards - but this is single phase so it's not that.

    So then I get him to be quiet and I am frenziedly scanning through the data banks: How can this be? What is that noise? What can cause this?

    About then I notice that the gauge pressures are almost exactly the same. What??? A brand new compressor isn't pumping? How the hell can that be?

    So I shut it off again and pause and ponder and go over the details of the install again in my head: running the mental video.

    It was just about then that I realized that I had neglected to open the service valves on the unit. <g>

    I laughed and leaped to do that - of course immediately contaminating the R407 with whatever non-condensible the dry pressure charge is. <g>

    In the end I did manage to get away without drowning - but just Barely. <g>
    I have seen scroll compressor on single phase running backward. I put it in last week. no pressure difference, but have amp draw and new hard start + cap. ran normally when I switch the common and run lead.

    speaking of 407: I have several liebert on it, and two split system feeding an HRV on it. don't have the experience to tell what's the advantage from one refrigerant to the other... but I could fix it when it's not working.
    Parts Changer Extraordinaire
    ------------------------------------------------------
    Have tools and gauges, will travel.

    RIDGID|YELLOW JACKET|UEI|TESTO|STANLEY|CPS|VETO| KLEIN|MILWAUKEE|MASTERCRAFT|

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