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  1. #1
    Join Date
    Jul 2002
    Location
    NorthEast
    Posts
    811
    Traulsen 2 door reach in box

    Medium temp ,Using R-134-A
    Cap system no txv
    Condenser is clean, the room is about 75 Degrees

    Tech said he was getting
    Suction; 18 Inches vacuum
    Head pressure : 124 P.S.I.

    Tech Solution: He is going to charge it
    My solution: Low charge And a high side restriction


    What are average operating R 134-A pressures ?
    After we rplace the drier , is there a good way of cleaning out the cap tube

    THank you



  2. #2
    Join Date
    May 2004
    Posts
    12,027

    There is no "really good" way to clean out a cap tube. There are devices that will but... You can try to blow them out with dry nitrogen @ 200 or more lbs. Nip about 1/2 off of each end and reinstall. If your compressor has overheated with POE the restriction may not be debris but varnish. You will not get the varnish out. Look at the paper labels on the compressor, are they darkend?


    The pressures for 134 are close to 12. Check here for a PT chart. http://www.refrigerants.com/pics/ptchart.pdf


    Run your hand across the cap tube and see if you can feel a drop in temperature or do you see icing where the cap goes into the evap? If you do, you probably have a restriction. Be sure to size it properly with Traulsen and use a Sprolan 032-s CAPT drier.

    I know that Traulsen parts are slow but call them for cap size or you can size the cap tube with HP, temp and refrigerant using a cap calculator.






  3. #3
    Join Date
    Jul 2001
    Location
    Gold Coast of Connecticut
    Posts
    4,582
    usally about 12/120-140 PSIG at 75 degrees

  4. #4
    Join Date
    Sep 2004
    Posts
    8
    Remove refrigerant, replace filter drier and cap tube (properly sized) Pull vacuum on system and slowly charge to about 13-17 PSI on suction. R134 systems are notorius for having restricted cap tubes after a overheat condition (seized fan motor,dirty condenser)

  5. #5
    Join Date
    Jul 2002
    Location
    NorthEast
    Posts
    811
    This site was origionally serviced by another contractor
    The original estimate called for a new compressor.
    We were called in to see if the compressor was operating.
    Our tech feels it is since it is pulling a vacuum.

    The compressor was running very warm

  6. #6
    Cap tube systems should be charged by weight. Normally, this info is on the data tag, or you can call Traulson's technical support and ask them.

  7. #7
    Mostly good advice so far, save for that notion about charging by suction pressure.
    If you have a known good system, and you know that system inside and out ... sure you can charge it up like that.
    But not when you've obviously got a restriction!!!

    The factory tech can convey with you the ID size and length of the OEM captube. Take thos emeasurements to Johnstone ot wherever you buy your parts, and then replace the captude and drier.
    And then weigh in the factory charge. Standard operating proceedure. SOP.

    Charging by pressures is NOT S.O.P., not in my book.


    If you want a cheat, try cutting off six inches and recharging the system.
    I have heard that works, sometines.
    If your like most of us here, you dont like replacing cap tubes. And for good reasons.
    Cap tubes, for the most part, we never installed to be removed and replaced.
    Just like the oil in pot compressors.
    Never designed to be replaced, checked, drained, etc.

  8. #8
    Join Date
    Sep 2004
    Posts
    8
    Hmmm... mechanically remove refrigerant, remove 6 inches of cap tube, re-solder tube, pull deep vacuum on system, add nitrogen to verify leak-free and add refrigerant to system just to still have restriction - great advice R12!! The question asked was about "average" R134 operating pressures on a reach in box.

  9. #9
    Join Date
    Nov 2003
    Location
    Wisconsin
    Posts
    458
    Resticted and probably overheated on a 134 system. You'll be back once or twice a week till you condemn it even after changing cap tube. Cut your losses and do it sooner rather than later.

  10. #10
    Join Date
    Sep 2001
    Location
    East Stroudsburg, PA
    Posts
    13,215
    Originally posted by joe kool
    Hmmm... mechanically remove refrigerant, remove 6 inches of cap tube, re-solder tube, pull deep vacuum on system, add nitrogen to verify leak-free and add refrigerant to system just to still have restriction - great advice R12!! The question asked was about "average" R134 operating pressures on a reach in box.
    Which, in your second and third posts as a member here, you have failed to answer properly, obviously, to make room for your sarcasm in replying to another member who generally dispenses excellent advice.

    Granted, there is an important step missing from his advice in this thread, but I'm certain that was an oversight.

    You'd do well to keep your smartass remarks in check, at least until that "new member" title is gone, and you get to know who you're trying to put down.

  11. #11
    i always try shutting comp off -watch rate of equalization (hopefully its not thru the valves),that should give a good indication of blockage,also temp clamp on suction while running should tell you charge level.

  12. #12
    Join Date
    Sep 2004
    Posts
    8
    sorry for the sarcasm dave...but if you live in a glass house - you don't throw stones !

  13. #13
    Join Date
    Jun 2002
    Location
    St Louis MO
    Posts
    1,382
    Originally posted by joe kool
    sorry for the sarcasm dave...but if you live in a glass house - you don't throw stones !
    after 4 yrs and 8k in posts....hes allowed to throw stones in my house, but pls dave , not hard its a small house

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