how do i use a PID?

This is an extremely noob question and I'm almost embarrassed to post it.

I'm basically trying to copy the countertop brutus using the exact same components (auber syl 2362). I'm pretty sure I have everything wired up correctly as everything is working, except maybe the PID.

I did a test run last night. I had it set up to heat and hold at 130F but the PID won't turn off the water element heater. It stayed on.

What am I doing wrong? Do I need to program the PID? How do I set the target temp?

How do you have the PID-SSR-Element wired up?

What am I doing wrong? Do I need to program the PID? How do I set the target temp?

Click to expand...

yes you do need to program it. you need to set the PID values in order for the controller to be able to function. otherwise its just an expensive, hard to use, switch.

i dont have that particular PID, but these settings should help a little (these are just an example, the thermodynamic properties of my system are most likely different from yours and you should tweak them as necessary)...

p= 1 to 5 (%), depends on the temp sensor type / range of the sensor
i= 20 to 40 (seconds)
d=0 (disabled; with a large stable thermal mass, overshoot compensation is unnecessary)
ot=2 (seconds; use '2' for SSR, longer for mechanical contactor/relay to prevent short cycling)
filt= try 1, if you want faster response, change to zero

Don't forget you also need to set the PID for the temp probe you're using and it could also be set by default for *C instead of *F.

Thanks everyone.

The problem was actually in my wiring. I connected an extra hot wire where I shouldn't have and so the power was always on.

It's working now but I still need program the PID.

Thanks again.

before you start playing with the actual P, I & D gain terms, most controllers have an autotune mode.

This should give you a good inital starting point, and for the average joe this should be sufficient. Then u can cycle thru the autotune P,I and D values and make tweaks if you are interested in it.

PID Tutorial

Yeah just run the autotune with the usual amount of water you have in a batch, it'll get it close, tweak it from there if you need to. Make sure you set the temperature probe properly though, that's a big one, but I think the default is a thermcouple. So only needed if you have an RTD.