Page 1 of 2 12 LastLast
Results 1 to 13 of 19

Thread: novar sensors

  1. #1
    Join Date
    Jul 2006
    Location
    wv moumtaineer
    Posts
    15
    need some info on trouble shooting novar sensors. new to this job @ wal mart tech division. have a case {ice cream} going off on alarm temp sensor showing +9 and case temp showing -4.i think i am looking for some parameters on checking this sensor.i have got some helpfull web addresses on this site,any info would be helpfull.

  2. #2
    Join Date
    Nov 2005
    Location
    Laramie, Wy
    Posts
    709
    only one approved way to check that sensor. Get a cup of ice and smash the hell out of the ice. Fill with water and continue to add and mash ice. You want kinda of a slushie style mix. Put sensor in that mix for a couple of minutes and read that temp at the cim board. If it is an old cim board, the sensor must read within +/- 1 degree from 32. If new cim style cim board you can recalibrate up to a certain level for a sensor. I think you can recalibrate the new cim boards for up to 8 degrees. To tell the difference on the cim boards, if you have to read it at the top of the cim at an odd angle, it is an old cim board and you will need to just replace the sensor. If it is a new cim, it will usually be mounted in a flat position and can be easily read.

    [Edited by mtnwrench on 08-29-2006 at 12:31 AM]

  3. #3
    Join Date
    Dec 2005
    Posts
    1,823
    If I am not mistaken, Novar sensor is life time warranty.

  4. #4
    Join Date
    Nov 2005
    Location
    Laramie, Wy
    Posts
    709
    Originally posted by just_opinion
    If I am not mistaken, Novar sensor is life time warranty.
    nope, they die all the time on Wally's stuff...

  5. #5
    Join Date
    Jun 2001
    Location
    Michigan
    Posts
    12,077
    Originally posted by just_opinion
    If I am not mistaken, Novar sensor is life time warranty.
    Novar would be out of business if they did that.

  6. #6
    Join Date
    Dec 2004
    Location
    Sunny So Cal!
    Posts
    649
    Originally posted by mtnwrench
    Originally posted by just_opinion
    If I am not mistaken, Novar sensor is life time warranty.
    nope, they die all the time on Wally's stuff...
    sounds like a salesman has been through here- lifetime warranty, oops guess I was wrong.....


    They TELL you their stuff lasts forever, and thats usually all they are willing to tell you about their stuff too.

    trust your own thermometer- I think Wally can afford a probe here n there...
    Look, just do your job, stay outta my way and we'll get along fine.

    Teach your kids to respect themselves and others with your actions- these little baboons will imitate you like it or not.

  7. #7
    Join Date
    Oct 2006
    Posts
    9
    Some Novar sensors do have a life time warranty. The catch is when they were originally manufactured. Check the date code on the sensor. It does not hurt to ask about the warranty.

  8. #8
    Join Date
    Aug 2000
    Location
    USA
    Posts
    4,979
    Home Cheapo uses Novar too. I used to get a dozen of each sensor from them at a pop. Between the employees tearing them off the poles and the sensors crapping out, you never had enough replacements. The sensors are junk. JMHO

  9. #9
    Join Date
    Sep 2001
    Location
    East Stroudsburg, PA
    Posts
    13,215
    Originally posted by Dowadudda
    Originally posted by just_opinion
    If I am not mistaken, Novar sensor is life time warranty.
    Novar would be out of business if they did that.
    That would just break my heart!

  10. #10
    Join Date
    Feb 2010
    Posts
    5
    Newbie with a starter follow-up question to this-what is the typical output on a Novar case sensor in Walmarts?

  11. #11
    Join Date
    Jun 2001
    Location
    Michigan
    Posts
    12,077
    this is an old post. An output is not a sensor. Sensors are inputs.
    People who think they know everything are a great annoyance to those of us who do.

  12. #12
    Join Date
    Feb 2010
    Posts
    5
    Yes, but they output some type of signal for the input terminal to read-voltage range, 4-20ma, resistance if a thermistor, etc. which is what I was after. I was curious what that output was on the common Novar sensor Walmart uses in their cases?

  13. #13
    Join Date
    Jun 2001
    Location
    Michigan
    Posts
    12,077
    Quote Originally Posted by cb1hvac View Post
    Yes, but they output some type of signal for the input terminal to read-voltage range, 4-20ma, resistance if a thermistor, etc. which is what I was after. I was curious what that output was on the common Novar sensor Walmart uses in their cases?
    when your asking that question to a person like me, who does this kind of work everyday, your using terminology incorrectly. And I am not saying this to be arrogant. It's very important for you to understand how your question could yield the wrong answer. So your informed and on your way.

    Analog Inputs used on Novar Case Input Modules are 5 VDC signal with a Milllivolt Return. The "return" value is the representation of the Temperature which is electronically interpreted to the Rack Refrigeration Controller.

    Novar sensors used on these are manufactured with a glass diode, so don't "manhandle" the sensor or drop it. It's delicate kinda. They say it's a low temp sensor. Well in our world it is sort of. It has the capability to read anything from -40 degrees to 88 degrees. They say low temp because other temp sensors which can read higher temps above 88 degrees are an entirely different kind of a sensor. For every 100' of wire run, after the first 100' of run, the sensor via the CIM, (case Input Module) must be calibrated
    because there is a loss of 1 degree of accuracy.

    Your readings with a meter: unlike CPC and Danfoss, with the refrigeration temp sensors, Novar does not have a chart based on the "return" value. They don't publish it or offer a mathematical equation to arrive at it that I am aware of. Now give me a second to explain your Milliamp next. Right now were still on "glass diode". With the CIM, you go through a calibration procedure with 32 degrees as reference. A glass a of crushed ice with the sensor in it.

    The Milliamp sensors: These temp sensors are used on the HVAC side. Typically. The 4-20 Milliamp return can be measured and referenced on a chart with a mathematical equation. I don't have it in front of me.

    You asked about what is "common". That is kinda funny when talking about the Walmart Novar World. Because they don't have standard commonality through out their family of hardware. It's all a little different. Little nuances that don't hold true to each hardware in the novar EMS system. The new OPUS should be. Because it's basically the same as the new Danfoss 255 system. I have not seen OPUS yet.
    Last edited by Dowadudda; 02-27-2010 at 12:19 PM.
    People who think they know everything are a great annoyance to those of us who do.

Page 1 of 2 12 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