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  1. #1
    Join Date
    Sep 2002
    Posts
    12,280

    Use a constant cut-in on a Norlake walkin ?

    Somebody on here gave me the idea a few days ago and an opportunity presented itself today to maybe try it.

    The subject is Norlake 40 walk-in. About 6' by 6' with what looks like a 1/3HP tin can compressor on it. OK; so maybe it's a 1/2 HP. <g>

    The same sized freezer actually does have a 1/2 HP on it - but at least the freezer has an iron body compressor on it.

    So anyway; on the 40 walk-in the defrost timer is defective - so the evap was frozen. Temp control is with a standard Penn remote bulb. I can't get enough differential to get away with just sticking that bulb into the fins - so how about a Ranco constant-cut-in stat? They are rated for 16 amps so the compressor load is OK for it.

    Can anybody see a reason why I Can't just resolve this coil freezing issue with a constant-cut-in control stat? And not bother replacing the timer.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  2. #2
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    4,397
    I work on a few of those little norlakes and they have factory installed constant cut ins. Every one works great.

  3. #3
    Join Date
    Apr 2010
    Location
    working overtime
    Posts
    844
    Personally i like the use of an ETC with the sensor mounted in the fins. I like the johnson A419 because i can set it up with a time delay to protect compressor from short cycling. I usually set my temps at 22 and with 15 differential. I have used this setup hundreds of times and it works like a charm consistently giving me 35 degree box temp. If you wanted to get fancy i saw a new ke2 etc that has the ability to program defrost into it. Have not use d one yet nor do i know the cost.

  4. #4
    Join Date
    Mar 2013
    Location
    swan valley idaho
    Posts
    727
    So when replacing something like his penn or a constant cut in with an a419 you would need to add some wiring? Those stats only have a wire in and out breaking a circuit. Looks like a419 needs a circuit with neutral also. How are u modifying wiring to install these? I do like the anti short cycle feature

  5. #5
    Join Date
    Apr 2010
    Location
    working overtime
    Posts
    844
    I pull my old stat wires back into control section. i mount the etc in desired place. my old stat wired are my no contact and common. and then i use a piece of sj cord and feed my power to my etc from my line voltage connection. I run my sensor to my evap and mount inside the coil and program and test. works great and is super easy.

  6. #6
    Join Date
    Mar 2013
    Location
    swan valley idaho
    Posts
    727
    So you are saying just run your hot/neutral or hot/hot for 208 from incoming power source to condensing unit, then take the two connections currently on a cold control/pressure control and use those to wire to the n.o. Relay points if i am understanding right?

  7. #7
    Join Date
    Apr 2010
    Location
    working overtime
    Posts
    844
    yup

  8. #8
    Join Date
    Mar 2013
    Location
    swan valley idaho
    Posts
    727
    Sounds like a good set up. The a 419 does have alot of features a cold control don't . Is reliability good. I just don't trust the electronic as much as a good ol ranco a12-1506. It is 2013 though, so probably time to start trusting them!

  9. #9
    Join Date
    Mar 2013
    Location
    swan valley idaho
    Posts
    727
    What about when you need a longer wire run- can you add a say 20 foot length of wire to temp sensor without reading getting messed up?

  10. #10
    Join Date
    Apr 2010
    Location
    working overtime
    Posts
    844
    they are pretty reliable. in regards to adding wire to extend your sensor you should be able to but i dont understand why you would need to add 20 ft

  11. #11
    Join Date
    Mar 2013
    Location
    swan valley idaho
    Posts
    727
    I worked on a walk in the other day that had one mounted at remote condensing unit next to time clock. Evap was about 30 feet away inside. I noticed sensor wiring had been lengthened

  12. #12
    Join Date
    Jul 2011
    Location
    Lehigh Valley, PA
    Posts
    427
    Hey PHM, with all of the talk of the Ranco constant cut-in this week, I decided to give it a try on an older R12 walk-in I service. An icing evap was a common problem likely due to heat leak and employee improper use. I am running R409 in it now.

    I installed the A12-701 on Weds morning. Cut in at 41F, min cut out at 15F. I have it holding at 37F as of this morning. I decided against the A12-700, felt that it would run too cold. (range 37F-11F) I only need below 37F--39F in my units. I'll know more next week.

  13. #13
    Join Date
    Jul 2011
    Location
    Lehigh Valley, PA
    Posts
    427
    Quote Originally Posted by cavalieri85 View Post
    Personally i like the use of an ETC with the sensor mounted in the fins. I like the johnson A419 because i can set it up with a time delay to protect compressor from short cycling. I usually set my temps at 22 and with 15 differential. I have used this setup hundreds of times and it works like a charm consistently giving me 35 degree box temp. If you wanted to get fancy i saw a new ke2 etc that has the ability to program defrost into it. Have not use d one yet nor do i know the cost.
    The A419 is a really nice temp controller. I also like the Ranco ETC111-000. Not as nice a display but does all else well without all of the jumpers. I use this unit for most of my repairs. But this week, wanted to try a Ranco constant cut in more or less as a test. In my job, I can get away with this as an in-house guy.

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