I set the element to PID and used a digital only pin (not a PWM) per the suggestion for SSRs. I was under the assumption it would vary the power by turning it on or off but at a slower rate then the PWM. It only is going to 0 or 100 percent and I am over shooting by a little over a degree. If I set the max power level to 50% it cycles as expected.
Thank you
Patrick
Are you saying it never reports a power percentage between 0 and 100?
Can you provide more specific details? Kettle confit, probe type, and the parameters you have set up in the PID?
Yes, I only see 0 and 100 nothing between.
PID Control Properties attached, I also tried the suggested values of 30,1, and 5. I am using a one wire in both a 30 and 50 gallon pot. Our system is a HERMS.
Thank you
Patrick
Ok thanks. 70/140/1 would be way too aggressive. The kI of 140 alone will immediately cause the integral component to pin the needle to either peg quickly. This is why the 50% cap is helping. If you are seeing too high a responsiveness, try reducing the kI further, including setting it to 0. 0 will cause the system to settle on a temp that is less than your target, but should be stable and without overshoot. Also, FYI kD doesn’t mean much in these slow moving systems.
The empiric values 30/1/5 are for roughly 7.5 gallons with a 5500W element. If your system’s liquid:power ratio is smaller, you will need lower coefficients... try 10/.5/5 etc.
