Results 1 to 6 of 6
  1. #1
    Join Date
    Nov 2008
    Location
    NELSON BAY AUST
    Age
    43
    Posts
    48
    Rep Power
    0

    high liquid line pressure?



    hi all,
    just wanna ask some opinions if poss, as some of you may know im new to commercial, i changed a small condensor unit today, it was a heatcraft kirby ba9 unit, i changed the dryer as well and was advised by our supplier to remove liquid reciever as it is a capillary system, i tripple evaced system and charged r22 (original used) i started up and system was slightly short soi added some more, i finished up with suct 47psi, -5°c sst, and 9°c on suct line exit cabinet (cabinet was not down to temp was at 12°c) that was 14k super heat, liq line worried me though it was up 380psi, 67°c sct, but the liquidline temp was perfect at 34°c, the system is approx 5 ft wide and has a coil built in storage area floor, it also has a static coil at top which is a horizontal 3 turn evap, no s/air or r/air readings avail but unit took 15 mins (once pressures wer ok) to cool from 27°c to 15°c and dropped fast, air on cond was 29°c air off was 39°c, after a while longer i began to get some flood back so i recoverd a small amount taking frost bak to around 25 cms from evap exit, my new suct pressure was 41 psi, -8°c sst, and still about 9°c on suct line, liquid line was still high at 335 psi, 60°c sct, and still about 34°c on liquid line, is it normal for a capillary controlled unit to have a higher liquid line pressure?? sorry for beating around the bush and sorry if i just confused yas with my dribble but any q's or input will be appreciated take it easy guys. oh, by the time i left it was 6°c and no more flood backs im confident its working ok but just not sure if liquid line pressure too high



  2. #2
    Join Date
    Dec 2004
    Location
    Australia
    Age
    52
    Posts
    519
    Rep Power
    20

    Re: high liquid line pressure?

    Quote Originally Posted by TECH TIM View Post
    the system is approx 5 ft wide and has a coil built in storage area floor, it also has a static coil at top
    Neither coil has fans?

    Coils without fans will run lower suction pressure sounds like it is over charged and thats why you have the high side pressure you have.

    Let is get close to temp and check then.

  3. #3
    Brian_UK's Avatar
    Brian_UK is offline Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
    Join Date
    Mar 2001
    Location
    Dorset
    Age
    76
    Posts
    11,192
    Rep Power
    60

    Re: high liquid line pressure?

    As Temprite says, check at design cabinet temperature.

    You action of 'adding a bit more' before the case temperature had stabilised at design gave you additional problems.
    Brian - Newton Abbot, Devon, UK
    Retired March 2015

  4. #4
    Join Date
    Oct 2008
    Location
    New Zealand
    Age
    46
    Posts
    33
    Rep Power
    0

    Re: high liquid line pressure?

    aim for a minus 20c sst at temp when charging a static coil. whatever the gas. some slight adjustment may be required but you'll be pretty close.

  5. #5
    Join Date
    Feb 2009
    Location
    telford
    Posts
    2,097
    Rep Power
    33

    Re: high liquid line pressure?

    was the condensor the same size as the original and what was the reason for replacement

  6. #6
    Join Date
    Aug 2008
    Location
    Baltics
    Age
    62
    Posts
    786
    Rep Power
    16

    Re: high liquid line pressure?

    I hope that Tech Tim himself, at least, stays safe and sound after the repair. I wish we were more often providing follow-ups on our problems, no matter what the issue was.

Similar Threads

  1. Superheat and Subcooling
    By Chunk in forum Fundamentals
    Replies: 42
    Last Post: 15-01-2011, 02:24 AM
  2. Suction gas <-> liquid line heat exchange and performance gains
    By DaBit in forum Technical Speculations
    Replies: 30
    Last Post: 18-05-2010, 01:52 PM
  3. need help! compressor kicking out on high pressure
    By SloFuse in forum Trouble Shooting
    Replies: 16
    Last Post: 19-08-2009, 04:46 PM
  4. About liuid line pressure drop.
    By wilsoncheung in forum Technical Speculations
    Replies: 15
    Last Post: 16-03-2009, 12:34 PM
  5. Building a wine cabinet
    By Rory in forum Technical Discussions
    Replies: 38
    Last Post: 13-07-2004, 08:28 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •