Results 1 to 6 of 6
  1. #1
    Join Date
    Sep 2003
    Location
    ISRAEL
    Age
    72
    Posts
    4,266
    Rep Power
    46

    A defrost controller thoughts.....



    It is a well known fact that all freezers controllers switch from colling to defrost at once.

    In case of hot gas defrost (HGD), this accrue when the evaporator is usually full of refrigerant.
    The liquid refrigerant is being pushed by the hot gas to the compressor head via a liquid separator that can not cope and the unfortunate result is damage to the suction valves and the pistons.

    To overcome this problem, I have connected an in line timer between the controller and the defrost solenoid, setting it for 4 min.
    This is enough time for the compressor to preform a pump down and get a smooth useful and quick defrost.

    Before any silly question, of course there is a KVC ahead of the liquid separator.

    Chemi
    Last edited by chemi-cool; 14-05-2008 at 08:20 PM.



  2. #2
    Join Date
    Jan 2006
    Location
    Valrico, Florida
    Posts
    517
    Rep Power
    19

    Re: A defrost controller thoughts.....

    Minus the 4 mins your using for pump down, is it still a sufficient defrost?

  3. #3
    Join Date
    Sep 2003
    Location
    ISRAEL
    Age
    72
    Posts
    4,266
    Rep Power
    46

    Re: A defrost controller thoughts.....

    Yes.

    The total defrost time is 30 min, every 3 hours at -20°C room temp.

    There are two evaporarors in the freezer.

    When I return from beatiful southern Italy at the end of may, I will post a few pictures {of the freezer....}

    Chemi

  4. #4
    Join Date
    Jul 2001
    Location
    Sydney, Australia
    Posts
    764
    Rep Power
    25

    Re: A defrost controller thoughts.....

    the controllers we normally use in supermarkets integrate an adjustable pump down time to allow for this phenomena
    ...and she said "give it to me you big fridgie"

  5. #5
    Join Date
    Sep 2003
    Location
    ISRAEL
    Age
    72
    Posts
    4,266
    Rep Power
    46

    Re: A defrost controller thoughts.....

    I was talking abot Dixell XR06CX which is commonly used or eliwell 974.

    Supermarket controlls are much more inteligent and vesatail.

    Chemi

  6. #6
    Join Date
    Jul 2001
    Location
    Sydney, Australia
    Posts
    764
    Rep Power
    25

    Re: A defrost controller thoughts.....

    ah I see, yes the little ones can be pretty basic thats for sure
    ...and she said "give it to me you big fridgie"

Similar Threads

  1. Carrier Transicold Container Problem
    By Shamel in forum Transport
    Replies: 39
    Last Post: 24-01-2012, 12:23 AM
  2. Replies: 12
    Last Post: 27-03-2011, 04:12 AM
  3. Toshiba RAV SM/SP1400 defrost problem
    By SteinarN in forum Heat Pumps
    Replies: 11
    Last Post: 20-02-2008, 05:25 PM
  4. No Power for Defrost Timer Motor
    By kln in forum Domestic
    Replies: 6
    Last Post: 21-01-2008, 09:22 AM
  5. Hot gas defrost vs Electric defrost
    By herdian in forum Industrial
    Replies: 19
    Last Post: 13-08-2007, 11:25 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
  •