Help please, PID Controller not displaying correct temp

Discussion in 'Slicers, Grinders, Tools, Equipment' started by howdydo, Sep 28, 2014.

  1. howdydo

    howdydo Newbie

    Hey guys,

    I have this "AGPtek K-Type SNR PID Temperature Controller"  [LINK]   and really have an issue, I cannot figure out.  The temperature is not reading as I would expect it to.  I followed all the steps from dward51 in a thread from about 18 months ago [HERE] and the wiring was super easy and straight forward.

    In a ice water bath I am getting a reading of around 210* F, I have confirmed I have the PID controller in F mode, and K type probe setting.  Although I cannot get a true temp reading.  I even tried to use the offset setting, to display a 180-ish offset on the display, so it would kind of work correctly, but after changing the offset in the PID< its still didn't display the right temp, still just the 210* in the ice water bath.

    I tried 2 different probes with this, same result, so I don't think it could be 2 bad probes.

    Even with the wrong temps, I can change the SET point to be higher, and the PID turns on the SSR, and below it the PID shuts it off.  So I know it is working otherwise.  Just getting a horribly off temp reading.

    I hope this doesn't mean its a bad unit, I suppose I can just send it back since I got it from Amazon and buy a new, better one.  I think I'll order the Auber anyway, even if this one can be remedied.

    Anyway, what do you guys think it could be?
     
  2. howdydo,

    Hop over this forum and post your question there. It's the electric brewing section of HBT. I have experience with posting tons of questions regarding wiring PID controllers and they are amazingly helpful. I've wired a 2 PID controller for my electric brewing system with their help.

    This forum is amazing for q, but I don't have experience using it as an electrical resource....not at all to say the folks here can't help.

    http://www.homebrewtalk.com/f170/

    Very sorry if I'm not supposed to be posting other forums. Just trying to help a fellow q-er out!
     
  3. howdydo

    howdydo Newbie

    Thank you so much. 

    Huh! Really strange, it appears I DO NOT need the jumper wires that are on the right side of the PID unit, only the TC should be connected there (apparently).  I'll try this tonight, when I get home.

    I know the write-up that dward51 made was based on a RTD thermocouple, but I didn't realize by me having a K-type thermocouple it would eliminate the need completely, for the jumpers on the right side.

    Again, I'll try tonight and report back with my results.  BTW, I found this out within about 5 minutes of reading on that beer brewing site you suggested.  Thank you so much.  I'm not sure if its against any rules here to suggest other sites, but it helped me for sure, quickly.
     
    Last edited: Sep 29, 2014
  4. Good to hear. Yeah there's tons of information on there regarding electric brewing and automation, especially since that's a bit more important on the brewing end than q-ing end. Good luck!
     
  5. howdydo

    howdydo Newbie

    Wow,

    Within about 5 minutes of being home from work I got the TA4-SNR-K type PID controller working just fine.  If anything its only off by about 6* in an ice bath and about 2* in boiling water.  Close enough for me!

    Here's what I did:

    Refer to this diagram in this post, as where I was starting, I was all wired like this, just to test that the temp probe and PID unit was working first.

    [HERE]

    I thought the unit was defective, probably because my controller and probe is for K type probes, as you read in the previous posts in this thread.
    • I removed the jumpers on the right side, from 7-10 and from 8-9, completely.  and only thing on the right side now is the probes connections, Blue on 7 and Red on 8.  Works like a charm.
    Cheers to anyone else who has this exact setup, you'll be fine!

    This is THE way I got it to work!!  No jumpers!!  :)


    Here is how NOT to do it...:

     
  6. dward51

    dward51 Master of the Pit OTBS Member

    Glad you figured it out.  I just saw your post and was about to answer. J & K type thermocouples *DO NOT* need the jumper. That is for the RTD type only.

    Also make sure you download the "better" programing manual which is in the original MYPIN TA4 thread.  I posted it once towards the start of the thread, and later in the thread there is an updated version.  They are much easier to follow than the stock Chinese MyPin manuals.

    Here is the MYPIN TA4 thread

    http://www.smokingmeatforums.com/t/...tructions-and-general-pid-ssr-info-by-request

    Updated manual is on page 2, but here is a direct link to the file in the SMF database

    http://www.smokingmeatforums.com/attachments/1131
     
    Last edited: Sep 29, 2014
    howdydo likes this.
  7. howdydo

    howdydo Newbie

    Yeah!  First of all, thank you for your patience and help with the person you helped out before.  I was thinking, that's exactly how I feel, no knowledge of PID's yet I can make stuff work if told how.

    I have it working, and thank to you I haven't fried anything in the process.  I hooked up the signal part first, to make sure it works, before proceeding to the power side of things.

    I look forward to many well controlled smokes on this cheapo smoker, but it'll meet my needs.  :)
     
  8. howdydo, it's sort of funny this problem you've had. It's the exact issue originally when I wired up my MYPINs for the brewery. I added the jumper when I was using a K-type probe and the readings were all over the board. Real happy you've got it wired in perfectly now. It's amazing how cheap you can get this sort of accuracy when smoking with electric.

    Be sure to post of final pictures of the setup please. Did you add this stuff onto an existing electric setup like an MES or did you build the smoker yourself?
     
  9. howdydo

    howdydo Newbie

    I was given a Brinkmann Gourmet Electric red smoker, and after reading up on it, I wanted to verify it could get hotter than I wanted, so I could control the temp with this controller.

    I'd rather have it hotter than not hot enough.

    Its definitely cheap, although I already ordered a Auber controller that's being shipped now.  Oh well, I'll have a backup I suppose.  :)

    I'll get the pictures tonight, I still need to put this controller into a project box to finish it up.

    Actually, here's everything I have so far.

    Some of these pics are the wrong way to wire up the PID controller, be warned.  :)

    In that pic showing the temperature, I had just plugged in the smoker not more than 20 minutes prior, so it was still heating up.  Totally empty, no meat, no water, nothing.

    I want to run a few tests to gauge what temps I'll see in different situations.







     
  10. I'm definitely curious what sort of high temps you'll be able to get out of this. A big issue with the digital electric models is the high end of the temps is usually kind of low for a hot and fast type cook. If a $40 upgrade and some wire could give it the ability to get up to 350-400 then it would be more than worth it!
     
  11. howdydo

    howdydo Newbie

    Yeah, that's what I'm going to be shooting for, because I want to do the Thanksgiving turkey in this, and other poultry, and I understand a higher temp is needed for crispy skin on those.

    Do you know of any upgrades that would do that?  Different heating element but still no more than 1500 Watts?  Other things?
     
  12. What size element does the smoker have? I wouldn't suggest any other modifications until you know what you're able to achieve with the new set up. I imagine your enemy is going to be loosing heat through the thin metal walls faster than the element can give it back. But again, a test will prove what you're able to sustain. 

    Typically higher temps are best for crispy skin on birds, but I know people do hot and fast briskets and pulled pork also. 

    Some tests will show any possible issues and then you can solve them from there.
     
  13. howdydo

    howdydo Newbie

    You know, other than 1500 Watts, I'm not sure of the element size.  I have seen some elements, shaped almost the same, on ebay, and other sites, that claim to have higher temps and still 1500 Watts.  I think, like you said, I'll run a few smokes on what I have now, and go from there.

    In Phoenix it doesn't get terribly cold, but it can certainly get to 30° around here, in winter.

    I already have fiberglass oven-door-seal rope, and am going to rtv-silicone that to seal up the small gap where the lid meets the body.  And I'll see what other seals I can make.  I think I'll keep it hot enough for the first few smoking runs.
     
  14. jckdanls 07

    jckdanls 07 Master of the Pit Group Lead OTBS Member

    If I'm not mistaking.. I think 1500w is highest you can go on 110v... have been known to be wrong before tho....
     
  15. Howdy, I meant the wattage not really the size so the 1500 watts is good. Jd is right and you won't be able to run any bigger on a 120v circuit. But you shouldn't need anything bigger really. If you can't get high enough try wrapping the outside of the smoker with a blanket of reflux. I know it's ghetto but it'll help trap the escaping heat for getting a higher temp.

    But I really think you'll be good to get to at least 350. A few tests will prove very useful. Hope it goes good.
     
  16. dward51

    dward51 Master of the Pit OTBS Member

    Let me interject this into the franken-smoker conversation.

    Just for the sake of trying, last week I was making 5 pounds of snack sticks.  Original plan was to hit them with smoke from a pellet tray in the WSM (no heat) and then move them to the dehydrator for final processing.  While they were in the initial smoking phase, I got to thinking......

    I wonder if that 1,100 watt el-cheapo heating element I picked up at Walmart for $14 would work for the heating phase if I put it in the bottom of the WSM?  Sticks had cure in them so time was not as much of an issue as it normally would be.  So I gave it a try.

    Nothing fancy, a stock heating element with the thermal limiter still installed (it will only get so hot and the limiter shuts power to the element off).  I used just the analog temp dial on the element for adjusting the heat.  I did use the DigiQ II to monitor the pit temps as it's more accurate than an analog thermometer (and I can see it from across the porch from inside the house).

    So here we go......

    Ran 4 hours of smoke at 125* no problem.  Then slowly bumped the heat up to 150* and final bump to wide open (remember still has the thermal limiter).  Achieved and held 185* which is plenty for snack sticks.  Took about 8 hours from start to finish (stuffed them the night before and let them rest in the fridge overnight).

    So to answer the question, can you use a PID on a heating element in a plain metal shell of a smoker - yes you can.    I'm thinking about getting the $39 1,500 watt Brinkmann electric conversion element and controlling it from a multi-stage PID like one of the Auber Instrument models.  I'm also confident that without a thermal limiter, a heating element will achieve much higher temps in this setting as well.







     
  17. Dave, great test. I'd be a bit concerned putting the plastic shell of one of those walmart single plate heaters through any higher heat than that, but the conversion kit you noted would be a great option for adding a bit of safety to the process. It's the same thing I was looking at when I was considering building an electric smoker. 

    I'm considering putting together a PID controller for my MES30 to be able to get higher temps than 275 even. I do have a question in that regard. Is the SSR and heat sink really needed? From my experience (limited), the SSR is used when the "on" and "off" switch is going to be needed ALOT.
     
  18. howdydo

    howdydo Newbie

    I was under the impression the PID controller is merely for maintaining the temperature you want to smoke at, without overshooting it.  I didn't think you could *raise* the heat on the existing element with one.  I figure when you plug the element straight into the wall, its on full bore, and whatever you get as a max temp, is the best it can do.

    From your post, it makes it sound like a person could get a higher temp out of an existing element.  Is this correct?  Or am I interpreting what you said, wrongly?
     
  19. If you plug a heating element directly into the PID and set a temp of say 300. The heating element will stay on until the thermo reads 300. The PID simply switches from supplying power to not supplying power. So with a simple smoker that only employs a heating element in a chamber, this would work well.

    With that said, my post about using it on an MES might be wrong now that I think about it because of the existing digital controller already attached to the unit. If I was to wire up a PID for the MES, I'd have to go into the electronics area of the smoker and find the wiring that feeds to the element itself and wire a plug to it to plug into the PID controller. I'm not sure that's a "mod" I'd be up for doing. I wonder.

    Edit: Howdy, I'll add that of course the heating element is going to have a max temp that it's even possible to reach. That'll depend on other factors like ambient temps and insulation and stuff. But the PID is there to control the element itself to maintain WHATEVER temp you set....as long as the element has enough BTU output to reach it that is.
     
    Last edited: Oct 1, 2014
  20. howdydo

    howdydo Newbie

    Ok, yeah, just as I was thinking.  My Brinkmann Gourmet Red Electric Smoker (why did I write that whole name out) doesn't have a regulator, that I know of, on the element, its just a plug in and go, and whatever temp you get, is it's max temp.  So it just goes ON for as long as its plugged in.

    I hoped I would get a higher temp out of it, that way, so the PID controller I wired up would maintain the exact temp I was looking for, generally 225°.  Although I also wanted to get it to achieve higher temps, for things like chicken and turkey and other smokes that I might want to do at higher temps.  I'll find out over time the high end of this smoker.

    I think I'll be doing a whole chicken or turkey this Sunday for a test.
     

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