PID Overshooting

Started by Majes, July 02, 2012, 10:47:47 AM

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Majes

Anyone have experience with PID overshooting?   Set temp = 225 and it overshoots to about 240, gradually drops to 219 then back up to 240.   This was over the weekend during record highs of 109 deg but I kept smoker in the shade.    Ran auto tune 3 times and still overshoots.

Auber says to set power at 50% (this is outH in the setup menu) so I will try that tonight.

Just wondering if others have had this problem.

mikecorn.1

I had a bad probe that was causing me get weird readings. I called auberins and spoke to Suyi. I was sent an email showing me how to test the probe. Long story short, they sent me a me a new one and mine was out of warranty. Good customer service. :)


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Mike

beefmann

was thinking it also might be a auto tune situation

TedEbear

Quote from: Majes on July 02, 2012, 10:47:47 AMRan auto tune 3 times and still overshoots.

When you run the autotune do you have something on the racks to simulate a load of meat, water in the bowl and the smoke generator heating element turned on?  If not, try wrapping a couple of bricks with foil and place them on the racks and fill the water bowl just like you'd do during a smoking session.  The autotune works best when it is done during conditions that simulate how you'll be using your smoker.

Majes

Yep Ted.   I had a foil wrapped brick and a bowl of water in there.   I ran more Auto Tunes tonight and it keeps doing the same thing:   does 2 overshoot cycles then Auto Tune stops (after almost exactly 30 minutes) and it hovers around 225 for 5 minutes, then goes up to 235, then back down to 225 for a few minutes then dips on down to 216.  Then another trip to 225 to say hello, then on its way up to 235.  And repeats the up and down for as long as you're willing to watch it.

I recorded all kinds of data and will try to email Auber tomorrow.  I don't know what else to do.

Can you tell me your cycle rate?  The PID was turning the elements on and off in about 2 second intervals.

pensrock

I'm not sure one brick is enough weight to simulate a real load. its important to tune near a real load condition. I think I would put in a good ten pounds. You should also check the thermocouple placement in the smoker. Do not let the tip of the T/C touch anything or it will get a false reading. I'm not sure where Auber suggests placing it but in mine I have it located just under the second shelf. I can control my temps +-1 degree. I do not think you should have to limit the output to 50% but I guess if they suggested trying it, why not? I work with industrial temp controllers at work all the time and never had to limit the output to tune an instrument. I use a Honeywell controller for my smoker and my cycles are set to 32. I do not know the setting for an Auber but I'm sure they can tell you.