Auber PID Temp Swing

[Otdrzman]

Yesterday was the first smoke attempt since the 900 watt element and auber pid upgrade. I smoked a 9 lb pork butt. I experienced around a 10 degree swing in both directions. I ran the auto tune about a half dozen times and also moved the probe around in the cabinet to various places. I placed the probe to the side just under the butt, a couple inches over the butt, to the front, to the rear, etc. I was using the center rack in my 4 rack smoker.  Never could get it to settle down. Its almost like the element is not responsive enough to maintain temp. Anyway, the pork butt turned out awesome so that's a plus but I have to admit I was a little disappointed in the performance. I was hoping to eliminate the temp swing with the upgrade. Pics coming soon. Thanks for any info you can offer.

[TedEbear]

Did you let the auto tune complete the cycle on its own?  It initially will ramp up and down way beyond what the setpoint is at and eventually calm down as it establishes its parameters.  It can take an hour or more and it will do this several times.

[pensrock]

Also it is important to simulate a load in the smoker when running an autotune. You can use bricks or whatever you want but the smoker will react different with and without a load.
I use autotume quite a bit on industrial controllers and every now and then it takes more than once to get it tuned in right. I now normally run two complete autotunes to get me close and manually fine tune it. After you run an autotune let it settle down for 10-15 minutes, then raise the temp some a see how well it controls. if not good then run autotune again and see what happens.

[Otdrzman]

Yeah, I let it complete the auto tune cycle several times. It just wouldn't settle down. The entire smoke it would fluctuate around +10 or -10 degrees of the setpoint. A couple days ago I ran a test with 4 foil covered bricks and had them in the same location as the pork butt. Had the same fluctuation then but I kind of ruled it out thinking that maybe the bricks weren't absorbing the heat like a similar weight butt would. I don't know. Maybe I have something not set exactly right. I thought that the auto tune would settle it out.

[TedEbear]

With the autotune you can run it while smoking the actual meat.  You don't have to simulate a load with something else.  Try running it with whatever you're cooking and see if it adjusts any better.