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  1. #1
    Join Date
    Jan 2006
    Location
    DFW Metroplex
    Posts
    4,910

    R22 to R407A Rack Conversion

    I haven't worked with this refrigerant up until about 2 weeks ago.......just finished a store - converting MT and LT racks to R407A. So far, I like what I'm seeing.

    For those who've got racks running with this juice, what are your thoughts on it?
    "The problem is the average person isnt tuned in to lifelong learning, or going to seminars and so forth. If the information is not on television, and its not in the movies they watch, and its not in the few books that they buy, they dont get it" - Jack Canfield

  2. #2
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,950
    If the conversion is done correctly, then it's ok.

    The glide can be a bit tricky when setting EPRs.


    No complaints so far.


    If the conversion isn't done right

  3. #3
    Join Date
    Jul 2005
    Location
    Southern California
    Posts
    596
    It's OK. Lost two suction stops a week or two after the conversion I did. They stopped holding.
    Knowledge is knowing that a tomato is a fruit. Wisdom is knowing not to put it in a fruit salad.

  4. #4
    Join Date
    Oct 2011
    Location
    Indiana
    Posts
    33
    Am I correct in assuming that due to the high glide, pray to your chosen deity that there's never a leak. If you find a leak, you'll probably have to pull everything out and start with a fresh batch. Not nearly as bad in a smaller unit with lets say 10 pounds, but a heck of a lot worse when your talking upwards of 50 lbs.
    I'm a n00b, so if there's any flaw in that logic feel free to correct me.

  5. #5
    Join Date
    Feb 2008
    Location
    California
    Posts
    2,071
    your logic is flawed

  6. #6
    Join Date
    May 2008
    Location
    brooklyn ny
    Posts
    103
    those did work with 407 in bj but i heard the shop i work with were having problems with the converting of r22 to 407 dont rember the latter but there are having a lot of leaks in gastets on compressors valves with orings and solonids did work on any converting but spoke to senior guys said it was a headbuster. let me know what yo think

  7. #7
    Join Date
    Oct 2011
    Location
    East Charlotte Area of NC
    Posts
    486
    The biggest thing with ANY conversion is changing EVERY rubber gasket/seal on the high side of the system. EPR's, DDR's, Heat Reclaim Valves, Split condenser Valves, Liquid Line solenoids, Hot gas solenoids, changing all the schrader cores and caps, receiver gaskets, tightening the packing on TXV's and access valves, CHANGING any of the older ball master valves... there is a method to the conversions... but as said before, if it is done right, it works well.

    I can't fix it if it won't stay broke..

  8. #8
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,950

  9. #9
    Join Date
    Oct 2011
    Location
    East Charlotte Area of NC
    Posts
    486
    I agree, but most of the customers we are doing only spec the high side. Nice thing is we would get paid to fix the low side leaks when they appear. So far, I have not seen any. We shall see.

    I did some re-commissioning of a couple of used racks that were R22 racks converted to R404 when installed. By converted in this respect I mean taking the 22 and MO out and putting 404 and POE back in. I didn't think I would ever fix all the leaks on those.

    And FYI - Our company didn't do the install

    I can't fix it if it won't stay broke..

  10. #10
    Join Date
    Feb 2011
    Location
    OH
    Posts
    149
    wondering why not use mo 99 .in place of r22.you dont have to change oil .

  11. #11
    Join Date
    Sep 2001
    Location
    East Stroudsburg, PA
    Posts
    13,215
    I've done a few.

    It's no big deal. I was in on around 120 502-404a conversions a few years ago, and they were a bigger pain.

    Haven't had any significant leaks to know if fractionation is a real issue. On the surface, based on the glide, it appears to be as bad as HP80, but having said that, I only ever saw one HP80 rack fractionated to the point that it needed to be pulled, and that was after three consecutive relief valve blasts, over the period of a week.

    So far I am happy with it.

  12. #12
    Join Date
    Mar 2012
    Location
    North Carolina
    Posts
    3
    Have been working with 407A for over 2 years, its good stuff.

  13. #13
    Join Date
    Feb 2009
    Location
    Wisconsin
    Posts
    313
    One issue we have seen is cracks on the discharge header developing. It is always the center compressor(5 comp. Hill racks) Have had 3 racks flat on gas just a few weeks after conversion. Engineers said add baffles at the compressor discharge. Since those were added, no other failures.
    You have to fight through some bad days to earn the best days of your life.

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