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42815Re: [new_distillers] PID Controller

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  • Bob Glicksman
    Nov 22, 2012
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      The PID setup is intended to smooth this out somewhat.  The data sheet specifies 1 deg F, but I don't know under what conditions they test this under.  You have to follow the auto-tune procedure in the manual in order for its "fuzzy logic" to learn the time constants of your specific system and figure out when to cycle the heater power on and off so that it doesn't overshoot or undershoot as much as a simple thermostat would.  There is also a thermostat "on/off" mode, but configuring the controller for this mode will probably result in the same amount of overshoot that you experienced previously.  So use the PID mode with auto-tune and let us know who well this controller did for you.
       
      I personally much prefer controllers for SSRs, since SSRs can switch very fast and the PID controller can then use a one second cycle or less vs 100 second cycle for a contactor.  This has a much greater potential to keep a very even flow of heat and thus much tighter temperature control.  This PID controller does have an SSR output, but it is only for 3 amps - too little for your 2KW heater.  It is designed for use with an external contactor and you already have the contactor, so hook it up and see how well it works. 
       
      If you are trying to control heat to control proof in a still, you might be better off to try some sort of automatic reflux control vs trying to keep the heat input controlled very tightly.  The book:  http://www.amphora-society.com/Designing-and-Building-Automatic-Stills-2nd-Edition--by-Riku_p_3.html has a lot of good information about this. 
      -----Original Message-----
      From: Gavin Flett <gavin_flett@...>
      To: new_distillers <new_distillers@yahoogroups.com>
      Sent: Thu, Nov 22, 2012 10:36 am
      Subject: RE: [new_distillers] PID Controller

       
      Ok, so it sounds like a similar method of operation to my Johnston A-419 temperature controller which basically turned it on full blast for a bit, then turned it off. I saw temperature variances of up to 5 degrees. For instance I wanted to achieve a temperature of 64C, and it would end up all the way at 69C. Does the PID setup smooth out the heat fluctuations at all, a little bit or a lot?


      To: new_distillers@yahoogroups.com
      From: bobg542492@...
      Date: Thu, 22 Nov 2012 13:17:21 -0500
      Subject: Re: [new_distillers] PID Controller

       

      Gavin,
       
      I searched out the manual and you should wire it as Jeri suggests.  If you use an external contactor to control power to your heater, the PID controller will cycle it slowly -- turn it on for some number of seconds, then off and repeat every 100 seconds or so.  The heat output from the 2KW heater will vary as this happens, but the PID controller will attempt to hold the temperature as closely as possible.
       
      Bob
      -----Original Message-----
      From: Gavin Flett <gavin_flett@...>
      To: new_distillers <new_distillers@yahoogroups.com>
      Sent: Wed, Nov 21, 2012 11:03 pm
      Subject: RE: [new_distillers] PID Controller

       
      Guys, I don't know the first thing about PID's. The terms used are mostly foreign to me, hence my trouble so far. If this is the wrong setup, then someone please tell me what I need to run a 2000W heating element for a RIMS.


      To: new_distillers@yahoogroups.com
      From: bobg542492@...
      Date: Thu, 22 Nov 2012 00:21:45 -0500
      Subject: Re: [new_distillers] PID Controller

       

      Hi Jeri,
       
      As I said, no I do not have the technical manual.  I was just pointing out that proportional control of the heating element is not possible with an electromechnaical relay.  The heater is either on or off, and the relay cannot be cycled fast enough to make it pseudo-analog.  If a thermostate-like mode is supported by the PID controller, that is fine, as long as this type of operation is acceptable to Gavin.
       
      Bob
      -----Original Message-----
      From: laxt57 <laxt57@...>
      To: new_distillers <new_distillers@yahoogroups.com>
      Sent: Wed, Nov 21, 2012 8:54 pm
      Subject: Re: [new_distillers] PID Controller

       
      Hi Bob
      Did you read the technical publication  for this controller?
      SYL-2372
      I did
      Jeri



      -----Original Message-----
      From: Bob Glicksman <bobg542492@...>
      To: new_distillers <new_distillers@yahoogroups.com>
      Sent: Sun, Nov 18, 2012 9:42 pm
      Subject: Re: [new_distillers] PID Controller

       
      I don't know this particular PID controller, but if it is going to use a PID algorithm (proportional-integral-differential control), then it needs to adjust the heater output, not just turn it on and off.  Some PIDs can rapidly switch an SSR in order to adjust the heat output.  They do this for turning on the relay for some number of AC half-cycles (about 16 ms each half cycle for 60 Hz AC), since the heater's response time is much slower and will average out the electric power being modulated in this way.  But this type of operation requires a fast electric power switching device (an SSR).  A contactor or other electromechanical relay is too slow to do this (and rapidly switching one on and off all of the time will wear it out in notime flat). 

      The only thing that you can realistically do with an electromechanical relay switching power to an electric heater is implement a "deadzone" type of control -- like an ordinary thermostat.  I'm not sure that this PID controller can do this.  Most PID controllers are far more expensive than a simple thermostat and there would be no reason to support this mode of operation.


      -----Original Message-----
      From: laxt57 <laxt57@...>
      To: new_distillers <new_distillers@yahoogroups.com>
      Sent: Sun, Nov 18, 2012 1:03 pm
      Subject: Re: [new_distillers] PID Controller

       
      Hi
      Sure, simple as piece of cake.
      The number 9 and 10 terminals provide power to the PID
      (only for the PID not the heating element)
      The 6 and 7 terminals control a relay for some sort of device
      The 4 and 5 terminals are input from a thermocouple

      So, I assume you are using this to control a heating element?
      To make it work, you will need contactor(relay) big enough to run
      your heating element.
      Also you will need a thermocouple  and a heating element of course
      The thermocouple is polarity sensitive, so you need to connect it
      the right way round, that is if you are asking form hot and you get cold
      swap 4 and 5

      ----------------
      |               |   4---------------- Thermocouple +
      |     PID     |   5---------------  Thermocouple -
      |               |   6---------------  Contactor------------------- coil RELAY--------- heater
      |               |   7---------------- Contactor------------------- coil RELAY--------- heater
      ----------------                                                        AC   AC
        9      10                                                            IN    IN
       AC    AC
        IN    IN

      Hope this helps
      Jeri



      -----Original Message-----
      From: grainbrewer <gavin_flett@...>
      To: new_distillers <new_distillers@yahoogroups.com>
      Sent: Sat, Nov 17, 2012 11:42 am
      Subject: [new_distillers] PID Controller

       
      I recently purchased a PID Controller. Not being at all familiar with electronics, I am having a very difficult time understanding the instructions. Is it possible for someone to read the instructions and translate them into lamens terms for me? Mostly I am unfamiliar with the wiring diagram and symbols.

      The PID is an Auberins SYL-2372 and I have a contacter to go with it model # CN-PBC302-120V.



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