By way of review, I have a 7CU chest type freezer I use for brewing and aging wine. I use a 125W heat lamp for warming and, obviously, the freezer for cooling. Colin Law graciously helped me tune his PID node for the cooling side last summer and it has been working flawlessly. (Thanks!) It's wint…

Inside one of the boxes. Sorry, that should have read two boxes of 12 bottles each with 6 loose bottles.

Here is the chart for the last 44 hours. [image]

Previously was it in the liquid in the bucket? If so that that is a vast change to the system.

It was inside a stainless steel tube about 12" into the liquid. This one was inside a cardboard box with the lid taped shut, no air flow. I think I would expect a little over shoot because of the insulation of the cardboard compared to a thin layer of food grade plastic. That's why I didn't give …

What you have now is measuring the temperature of the air inside the box, which will react completely differently to the temperature of gallons of liquid. In fact I am surprised it controls as well as it does. It just goes to show how tolerant PID is.

It's a temporary situation. As soon as I can free up some room in my aging freezer I'll move it over there. When I start a batch of black currant wine, 3 gallons, I'll update the chart.

Well looking at the time to the undershoot the Integral time is not too small (too small an integral time will give ringing). If you were measuring the temperature with a sensor with greater resolution then the first thing would be to put in some integral, but the trouble with a DS18B20 is that onl…

A type K thermocouple would give a linear temp reading but I don't see anyone on the forum interfacing one to nodered. Besides that, I'm not sure I want to start over. :wink: I have a can of puree black current I want to try...

I wasn't suggesting you did start over. You just have to accept the limitations of the 'cost effective' hardware you are using. I don't suppose it matters if you overshoot a couple of degrees on initial start anyway. If it did you could ramp the setpoint down (or up) in order to bring it down gen…

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DS18B20 PID Tuning on the warm side

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Backup 17 March 2019 14:25 40

Just for curiosity sake and for future reference, what would be the best practice for adjusting parameters to compensate for the over shoot?

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DS18B20 PID Tuning on the warm side

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