Page 1 of 6 123456 LastLast
Results 1 to 13 of 71
  1. #1
    Join Date
    Aug 2013
    Location
    Omaha
    Posts
    640

    Caravell Freezer giving us hell

    Whats up everyone I'm new on this forum. I'm about 8 months fresh into my new refrigeration job and I absolutely love it.
    I have this freezer that seems to have literally stopped me and my coworkers in our tracks

    Its a caravell 1 door reach in ice cream freezer with hot gas defrost. This thing has had so much work done to it and its just kicking our asses...New compressor, 3 different cap tubes, new crankcase regulator twice...and the darn thing still wont go below 4 degrees. The refrigerant is 404a and my pressures look absolutely perfect. at 5 degrees I have a 10psi suction and 250 head. just no matter what we do we can't get it to go lower than 4 degrees...

    I was starting to think that the hot gas solenoid might be leaking by a little bit but my coworkers don't think so cuz the hot gas line isn't really warm at any degree.
    Any advice guys? Caravell is based out of denmark and they won't release any oem details about the cooler. We installed a .036 cap tube by comparing it to the original but something is still not right here i believe

  2. #2
    Join Date
    Jun 2009
    Location
    DFW, TX
    Posts
    674
    What is your evaporator superheat? That will tell you whether your pressures are right or not. Hot gas line may not be warm if it is leaking by just a little. A destructive test if you are out of options is to use a pinch off tool to pinch the line off. If suction pressure drops, then it was leaking by. If not, try to re-round it, then cut out the spot the next time the system is opened.

  3. #3
    Join Date
    Aug 2013
    Location
    Omaha
    Posts
    640
    superheat...exactly...let me tell you guys something...I'm not going to be the one to tell my coworkers that they're doing their job wrong...but they all tell me that superheat and subcooling is a waste of time...
    Quite frankly I'm glad u asked me to check that cuz everyone else thinks that won't tell me anything.
    So my next question...what superheat value should I be looking for?

  4. #4
    Join Date
    Aug 2013
    Location
    Omaha
    Posts
    640
    only other thing I've noticed is that when it comes out of defrost the head pressure skyrockets up to like 350 for a few minutes until the suction comes back down is this normal?

  5. #5
    Join Date
    Jan 2013
    Location
    florida
    Posts
    717
    try turning down the thermostat ?

  6. #6
    Join Date
    Oct 2009
    Location
    Raleigh, NC
    Posts
    799
    You're pressures aren't perfect. 10psig is far too low with the box at 5 degrees. You need more refrigerant in the evaporator, or you need to make sure you have load on the evaporator (fans running, all plenums in place, evap fan(s) rotating in the proper direction, etc.).

    The CPR valve should be adjusted to limit suction pressure after defrost. This will keep your head from going too high after defrost.

  7. #7
    Join Date
    Feb 2006
    Location
    Phoenix,AZ
    Posts
    2,894
    Suction Pressure seems low. What is the design TD? What cap tube does the manufacturer recommend? Are you taking suction psi ahead of the CPR or after? Is the charge weighed in?

  8. #8
    Join Date
    Jan 2010
    Location
    Toronto,Ontario Canada
    Posts
    356
    i would start off at the pressure switch and or the thermostat. cpr valve should be adjusted. thats my 2 cents. its most likely something easy and right in front of u. have fun and hope u fix it
    Get er Done!

    Do what has to be done
    when it has to be done
    as well as it has to be done
    And doing it all the time.

  9. #9
    Join Date
    Oct 2011
    Location
    Chicagoland Area
    Posts
    4,690
    Quote Originally Posted by UmmScott View Post
    superheat...exactly...let me tell you guys something...I'm not going to be the one to tell my coworkers that they're doing their job wrong...but they all tell me that superheat and subcooling is a waste of time...
    Quite frankly I'm glad u asked me to check that cuz everyone else thinks that won't tell me anything.
    So my next question...what superheat value should I be looking for?
    This is an odd answer if you ask me. What SH reading do you think you should be looking for?
    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

  10. #10
    Join Date
    Jan 2010
    Location
    Toronto,Ontario Canada
    Posts
    356
    isnt usually sh on a freezer 6-8 coolers 8-12 and ac's 12-15 depending on the orfice. but thats just what i was taught in school
    Get er Done!

    Do what has to be done
    when it has to be done
    as well as it has to be done
    And doing it all the time.

  11. #11
    Join Date
    Aug 2013
    Location
    Omaha
    Posts
    640
    Thanks for the input guys...I've set the cpr valve to around 35psi....as far as the pressure before the cpr valve my boss just told me to open it all the way and that will tell me my evap pressure. Thermostat is set for neg 10. The charge was weighed in, it holds 10.9 oz. The original cap tube I BELIEVE is .036 that we measured...but like i said the oem won't release any parts info about the cooler

  12. #12
    Join Date
    Aug 2013
    Location
    Omaha
    Posts
    640
    for superheat i was thinking around 8...but everyone at work tells me to "screw that" and just go by pressures...I think they're wrong about that tho. superheat and subcooling tell u so much more ****

  13. #13
    Join Date
    Feb 2006
    Location
    Phoenix,AZ
    Posts
    2,894
    Are you serious! The oem won't tell you the size of the cap tube?

Page 1 of 6 123456 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