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Here's one for you to gobble up

No physical blockages in the system.

Low side gauge reading at the SLSV is in a vacuum.

Both service valves are cracked off the backseat.


  • Eugene SilbersteinEugene Silberstein Member Posts: 1,380
    Here's one to gobble up

    You are called to a restaurant where the walk-in refrigerator is not operating. The system is operating with a capillary tube metering device. You arrive on the job and find that the suction line is damaged/broken/cracked, the system charge has been lost, the pressure control has been jumped out, and the compressor is still operating (in a vacuum).

    Since you do not know how long the system has been running like this, you decide to replace the condensing unit, as the oil in the compressor is likely acidic and compressor damage may have occured.

    You obtain a replacement condensing unit that is equipped with the compressor, condenser coil, receiver and fan motor...

    You replace the condensing unit, install new filter driers,
    thoroughly clean the system with dry nitrogen, perform a triple evacuation, recharge the system and start it up.

    The low pressure gauge immediately pulls into a vacuum and you continue to add refrigerant to the system.

    You add refrigerant and the low side reading remains in a vacuum.

    You add more refrigerant... low side still in a vacuum.

    You add more refrigerant... low side still in a vacuum.

    You add more refrigerant... low side still in a vacuum.

    You add more refrigerant... low side still in a vacuum.

    You add more refrigerant... low side still in a vacuum.

    You add more refrigerant... low side still in a vacuum.

    You add more refrigerant... low side still in a vacuum.

    Your high side pressure starts to climb and climb and climb and climb.

    What did you do wrong?

  • SteverinoSteverino Member Posts: 140
    I'll shoot....:-)

    #1.) Either the tec. didn't crack the LLSV on the receiver of it's front seat, but I doubt it.....OR

    #2 There is so much crap in the cap tube, there is a solid plug.

    That's my story and I'm sticking to it.:-) I hope there wasn't any turkey in there.

    Mike T.
  • Eugene SilbersteinEugene Silberstein Member Posts: 1,380
    Are you changing....

    Are you changing your identity, Mike?
  • Eugene SilbersteinEugene Silberstein Member Posts: 1,380
    A dirty Cap Tube

    A dirty capillary tube would definitely cause this problem, but let's assume that the technician did a very thorough job of cleaning out the system and the capillary tube is perfectly clean and free from any debris.

    Also, when the system was started up, both service valves were cracked off the backseat, so the gauge readings are accurate.

    The main reason for me posting this scenario is that it happened to a friend not very long ago.

    Back to basics....
  • SteverinoSteverino Member Posts: 140

    I dont know what's going on......
  • SteverinoSteverino Member Posts: 140
  • SteverinoSteverino Member Posts: 140
    How do I get rid of Steverino, whoever that is.??

  • SteverinoSteverino Member Posts: 140

  • SteverinoSteverino Member Posts: 140
    Sorry about that...

    I had to search and destroy steverino.......Now I can contunue with thought.

    Mike T.
  • SteverinoSteverino Member Posts: 140

    Possible copper flare plug on the suction SV was not removed when flared into it??? OR>..............

    Something is blocking the reading at the slsv. Can readings be obtained at the SL filter dryer? If so what are they? Also 1 more thing,...if taken at the SL filter dryer, is the gauge schrader core depressor engaging the schrader core?

    Mike T.
  • TechmanTechman Member Posts: 2,144

    The BEST holiday spirit to everyone!From my experience,cap tubes and recievers do not mix so well together! At startup there is no liquid flow into the liquid line so the suction press stays low for awhile.Then the reciever starts filling up! And after that they still do not work well together.May all have room for desert!
  • Eugene SilbersteinEugene Silberstein Member Posts: 1,380
    Ding Ding

    You are indeed correct Terry!

    A friend did this the other day. He was scratching his head and finally had to call for help.

  • TechmanTechman Member Posts: 2,144

    Hi Professor! Also, I do not mix L.P. controls and cap tubes, except when the L.P.C. is acting as a loss of charge control .The pressurers equalize rapidly on the off cycle.!
  • SteverinoSteverino Member Posts: 140
    wow....My Bad...:-)

    Like you said Gene,..Back to basics. I will be the first to tell you that I sometimes jump into step 6 overlooking the basics. Nice call Terry!!!:-) I have seen that before, but its been a while. Usually if we do replace an older unit we purchase the evap. w/ TXV and go new. I have seen though,... plugged cap tubes that will free up during clean up procedures and if you don't get the crud out, guess where it ends up, right at the first part of the cap tube. You will get that frost line after the plug thinking there is insufficient charge...

    Mike T.
  • MartyMarty Member Posts: 109
    traulsen does it

    According to traulsen it will work :) OEM reciever and cap tube and tech support swore it was supposed to be like that.
  • don_182don_182 Member Posts: 69

    it only a one time mistakes.I too strach my head on that very same thing one time.

    How about this one.A cap tube system with no receiver?

  • Eugene SilbersteinEugene Silberstein Member Posts: 1,380
    Have a great day

    All the best to you and yours.
  • Eugene SilbersteinEugene Silberstein Member Posts: 1,380

    Is that (your) post correct Don?
  • don_156don_156 Member Posts: 87

    Are you talking about how I mis-spelled scratch

    Sometime the finger is faster then the mind.

    Happy Thanksgiving!!
  • Eugene SilbersteinEugene Silberstein Member Posts: 1,380

    Not at all, Don.

    You mentioned "How about a cap tube without a receiver" and cap tube systems are intended to operate without them.

    I was just checking to make certain you said what you wanted to say.

    You have mail.
  • don_182don_182 Member Posts: 69

    Thanks Professor..I can see it more clearly now.

    Yes the question should have been pumpdown without a receiver.Not a problem in most cases however,I have seen a need for them on system with very long linesets.

    Yes, I'm in on the the other issue as well.
This discussion has been closed.


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