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[TheStand]

If set for 225 it will deliver pellet for a set time with no consequence to temp.

This is not true for my non-PID Traeger controller except when set to smoke. Any setting other than smoke, the auger runs full time until the set temperature is reached and then it reverts to the smoke mode until the temperature goes below the set temperature. The auger then starts continuous as the cycle repeats. In the smoke mode, it is a predetermined on-off cycle controlled by the P setting with no regard to temperature.   

I'm sure Non Pid controllers use a home grown Algorithm to run the auger. I assume this is how my Yoder and Cookshack's controllers work. Just a different method to get the desired result.

Most work on an "AND Gate or NAND gate" logic. What is the desired temp? Is it at or above desired temp? If "NO" then run raise temp cycle. If "YES" then run selected "P" cycle.


Most standard controllers only see "above", "equal to" or "below" and have preprogrammed cycles for each.

[GatorDave]

Thanks for all of this great info.  It is exactly what I was looking for.

[slaga]

I've never seen a pellet grill that keeps temps within 0.5 * of the set temperature, PID or no PID. The fact the pellets are not uniform in size, specifically the length, prevents any controller from being that precise. So that is this manufacturer's hyperbole.

I do not subscribe to the idea that a PID is the best controller. I would rather have a controller that allows the user the ability to pick the minimum flow rate and the maximum flow rate and it just oscillates between the 2 as it passes the set temperature. Then the user has the ability to program the amount of temp swing on a cook by cook basis.

You just described the Savannah Stoker Controller.

I set my Minimum (outL) and my maximum (outH). The difference is that it doesn't just go between the two. It uses the "autotune" feature to determine how your grill responds to temp changes and then uses that info to control the temps. It determines the percentage of pellet drop in a 20 second cycle time to reach the desired temp. Bump it a few degrees and you only need maybe 15% of that time (or 3 secs auger time every 20secs). jump from 200 to 350 and it says you'll need 80% (or 16 secs every 20 sec cycle) and then it will decrease that number as you get closer so you won't overshoot but a few degrees.

Actually I described the controller on the PG500 / PG1000. I am very familiar with the Savannah Stoker as I bought 3 of them over the years. It is my favorite controller that I have used.

If set for 225 it will deliver pellet for a set time with no consequence to temp.

This is not true for my non-PID Traeger controller except when set to smoke. Any setting other than smoke, the auger runs full time until the set temperature is reached and then it reverts to the smoke mode until the temperature goes below the set temperature. The auger then starts continuous as the cycle repeats. In the smoke mode, it is a predetermined on-off cycle controlled by the P setting with no regard to temperature.   

Unless your Traeger is different than the others I've worked on.. The only time the auger is "full time" is at start up and even that is for a set time. Then after startup if the temp is below the set temp it has a programmed cycle time to raise the temp to the desired temp. And then after that... Yes, if it is at or above set temp it runs on a "Pause" timing depending on the 'P" setting. With a standard "non pid" controller the auger is controlled by 2 factors. Is the actual temp below set temp? If yes then run the raise temp cycle... Or is the actual temp equal to or above the set temp? If yes then run the selected Pause "P' cycle.


If your grill was 15° below the desired set temp and the auger ran full time until it reached the set temp... Think about how long it takes a grill to respond. To increase 15° on the RTD might take 5 or more minutes. Now run the auger full time for 5 minutes and the grill temp would probably rise about 100°+ instead of the 15° needed.

The stock 180 controller on my Lil Tex (BBQ07E) ran exactly as hughver stated. At any setting other than smoke, when above the set temperature it ran at the P-setting. When below the set temperature the auger ran 100% of the time until the set temperature was reached. It ran at the P-setting or 100% depending on whether it was above or below the set temperature. Nothing in between, ever.

[slaga]

A PID controller looks at the set temperature, how far the actual temp is from the set temperature and how fast the actual temperature is approaching (or heading away from) the set temperature and calculates what it thinks should be the proper amount of fuel to bring it to the set temperature. It makes these calculations hundreds, if not thousands, of times per second and when the the cycle time is up, it goes with the latest calculation to pick a percentage of time to run the auger for the next cycle time. It does this over and over and over. It does not look at the previous auger times at all. It just looks what it thinks is the correct amount of fuel to bring the grill to the set temperature and does it.

There are many types of digital controllers. The PG500 / PG1000, Yoder, GMG and others I am sure do not have a PID, but their digital controllers work fine. The PG500 / PG1000 lets you pick the maximum and minimum fuel rates and just oscillates between the 2 as it passes the set temperature. The user can adjust the temp swing on a cook by cook basis. The others have a more calculated operation where they look at the current temp and the target temp and calculate the amount of fuel needed to bring it to the target temp. At the end of the cycle time it looks at what it did last time and how much closer it got to the target temperature and adds or subtracts a little auger time to bring it to the set temperature. They are mathematical but not PID.

The Traeger / Ortech digital controllers more or less run at their minimum / maximum fuel rate when above or below the set temperature. It is a very basic digital controller.

Here is my opinion: PID controllers are better than the basic Traeger / Ortech controllers. I do not feel PID is necessarily better than the digital controllers in the PG500/PG1000, Yoders, GMGs, etc. So to answer the OP's question, no you should not make a PID controller a requirement in your grill selection. You will be taking a lot of very good grills out of your pool of choices.