Page 1 of 3 123 LastLast
Results 1 to 13 of 29
  1. #1
    Join Date
    Jan 2012
    Location
    Oregon
    Posts
    101

    Reachin produce cooler problems

    Hi,

    I have a reachin produce cooler that is shutting down. The high pressure control is shutting the compressor down. Here are the symptoms. The cooler is a r404 unit. It was 95 dg. Ambient.

    High head pressure, should be 330 but was reading 380
    High low pressure, should be 50 but was reading 68
    High superheat, it was 20 dg to high
    Low sub cooling, about 2 dg low.

    The cooler should be around 38 dg but it keeps shutting down and warming up.

    I'm thinking that there is air or non condensables in the system. I'm thinking I should recover the refrigerant, evacuate and change change the filter drier. Then recharge with virgin refrigerant.

    Any opinions would help.

  2. #2
    Join Date
    Oct 2012
    Location
    Wisconsin
    Posts
    4,259
    I hate to ask, but have you cleaned the condenser. Even if it looks ok from the outside, it still may be dirty. Also, what kind of expansion devise, tev or cap tube?

  3. #3
    Join Date
    Jan 2012
    Location
    Oregon
    Posts
    101
    It has a tev valve. And yes iv cleaned the condenser. It's a older unit. It's been retrofitted to r404. And I forgot to mention it has a lot of bubbles in the sight glass. Almost looks like the refrigerant is boiling. There that much bubbles. Thanks for your reply.

  4. #4
    Join Date
    Mar 2013
    Location
    swan valley idaho
    Posts
    732
    You need more 404a. Add until u have no more bubbles.

  5. #5
    Join Date
    Oct 2012
    Location
    Wisconsin
    Posts
    4,259
    Where is your high side gauge manifold hose connected, liquid line, discharge line?

    If you have a restriction upstream from the sight glass, it will flash.

    Possible you have a restriction - plugged drier or other restriction. If it was retrofitted to 404a, the oil may have been changed to polyol ester. Polyol ester oil acts like a detergent, so if there was any crap in the system it will loosen it up and plug driers and cause other problems. Could be non-condensables as well.

    Is there a noticeable temperature drop across the drier right now?


    I think you're on par, pull charge, change drier, blow out system with nitrogen to ensure no other restrictions. Pull a good vacuum and weigh in the correct charge (if applicable).

  6. #6
    Join Date
    Oct 2012
    Location
    Wisconsin
    Posts
    4,259
    Another thing too, I see your post count is 49. If you haven't already, apply for pro membership. We can get into a better technical discussion in the pro forum.

  7. #7
    Join Date
    Jan 2012
    Location
    Oregon
    Posts
    101
    My high side is connected to the receiver. If its low on refrigerant the pressures should be low, right? So I don't think it's low. I really think its a restriction of sorts. Thanks for the help.

  8. #8
    Join Date
    Oct 2011
    Location
    Chicagoland Area
    Posts
    4,760
    What is the control set for? If it's set for 380, it's set too low. I'm also not understanding how you are determining what the pressures "should" be, unless you are familiar with this unit and if that's the case, how did the non condensables get inside? Also, the SH being 20* too high. Where are you checking your SH at? If it's not at the coil, it doesn't really matter as there are a number of other reasons the SH at the pump could be high. Does the unit have a headmaster?
    Officially, Down for the count

    YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

    I know enough to know, I don't know enough
    Liberalism-Ideas so good they mandate them

  9. #9
    Join Date
    Aug 2004
    Posts
    20
    Quote Originally Posted by bigbucks View Post
    Hi,

    I have a reachin produce cooler that is shutting down. The high pressure control is shutting the compressor down. Here are the symptoms. The cooler is a r404 unit. It was 95 dg. Ambient.

    High head pressure, should be 330 but was reading 380
    High low pressure, should be 50 but was reading 68
    High superheat, it was 20 dg to high
    Low sub cooling, about 2 dg low.
    You aren't getting rid of the heat. Airflow, dirty coil. No restriction since the subcooling isn't high. No air in the system for the same reason.
    Post actual temps. Gives a better picture.
    Out of curiosity. What are you looking for, for subcooling and superheat? Where are you measuring both?

  10. #10
    Join Date
    Jun 2008
    Posts
    73
    If you suspect non condensables, pump the unit down......if you can....if you can't pump down then shut the king valve and then shut off the unit. Disconnect the compressor and allow the condenser fan to run for half an hour. Measure your ambient temp and check it against your hi side pressure. If they don't match you have crap gas.

  11. #11
    Join Date
    Sep 2002
    Location
    Virginia
    Posts
    3,304
    is there a shroud on the fan ?? I bet not

    I've made my own shrouds from those cheap alum foil pans they have in most kitchens .... with layers of foil tape and zip ties

    Or plexi glass if you really want to get fancy

    Or you can be a sissy and order one from manufacturer

    If it does have a shroud already , might need a bigger pitch blade

  12. #12
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,867
    Low subcooling almost rules out non condensibles.

    You'll tend to see higher subcooling with non condensibles in the system.

    Clean the condenser, check the condenser fans, etc.

  13. #13
    Join Date
    Sep 2002
    Location
    Virginia
    Posts
    3,304
    with this being a retro fit ..... he may need to retro some other stuff , like a fan blade that pulls little more air , possibly motor too

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event