Defrost Timer - Stop Compressor or Not ?
Results 1 to 7 of 7
  1. #1

    Defrost Timer - Stop Compressor or Not ?

    My question pretains to a walk in freezer with a Copeland compressor (exterior of bldg.) 40ft. from walk in cooler (inside bldg). Evaporator is higher then compressor.
    I'm new to refrigeration and have seen defrost timers wired to shutoff the compressor and liquid solenoid valves and some that only shut off liquid solenoid valve and let the compressor cycle on pressure. Some defrost timer installation instructions actually show shutting off the compressor and using the temperature switch to shutoff the liquid solenoid but not the compressor. My question is what method is best? I'm leaning to using the defrost timer in series witht the temperature switch and just letting the compressor run on pressure control. From everything I gather in studies that would allow the liquid to stay out of the EVAPs during off cycling (both temperature and defrost). But is this as safe as also turing off compressor?

  2. #2
    Join Date
    May 2011
    Location
    New York
    Posts
    307
    IMHO, use the timer to cut off the liquid solenoid.
    Extended dehydration is the key

  3. #3
    Join Date
    Sep 2010
    Location
    Florida
    Posts
    88
    Quote Originally Posted by Moparmyway View Post
    IMHO, use the timer to cut off the liquid solenoid.
    I agree, use a timer.

  4. #4
    Join Date
    Aug 2006
    Location
    st.petersburg,fl
    Posts
    800

    Lightbulb

    Systems should be on a pump down, Timer controls the solenoid...
    Isn't sanity just a one-trick pony anyway? I mean, all you get is that one trick, rational thinking, but when you're good and crazy, well, the sky's the limit!

  5. #5
    Thanks for the advice. I'll wire the valve in series with the thermostat and defrost timer. Is there any real concern about only having pressure for the compressor controls...i mean the failure of one pressure switch could cause compressor problems?

  6. #6
    Thanks for the advice............I'll wire the thermostat in series with the defrost timer and close the liquid valve. So no real concern about running the compressor with just the pressure switches for control?

  7. #7
    Join Date
    Aug 2006
    Location
    st.petersburg,fl
    Posts
    800

    Lightbulb

    If you lose your charge low pressure switch will catch... I like to use the dual pressure controls that have a manual reset on high pressure switch if system does not have one I will usually install a screw on manual reset high pressure cut out... other than that you should be fine...

    Hope this Helps...
    Isn't sanity just a one-trick pony anyway? I mean, all you get is that one trick, rational thinking, but when you're good and crazy, well, the sky's the limit!

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