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[ATR621] PID regulation

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user7736
Posts: 19
Joined: 25/02/2014, 13:37

[ATR621] PID regulation

Post by user7736 »

Hello,

Client has ATR621 and water container (50 litres) with ~3kW heaters.

systems has to be warmed up to 65C and maintained for 60min.
After PID manual tuning- system got overshoot up to 4-5 C, and the controller very slowly let water cool back to 65C, and this is too slow for process. Heaters power is not very big compared to systems water volume.

Can you suggest any PID parameter to change?
Pixsys tecnico 1
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Re: [ATR624] PID regulation

Post by Pixsys tecnico 1 »

Hi,
can you please write the PID parameters that the autotuning process has calculated?
(turn autotuning OFF before) p11[TunE] to "diS"
We need parameters P19, P20, P21, P22

Do you use SSR output with a solid state relay or relay output with contactor?
user7736
Posts: 19
Joined: 25/02/2014, 13:37

Re: [ATR624] PID regulation

Post by user7736 »

Hi.

Now we have this device here in our office.
And we are testing it with some other heater, that has also big inertia.
19. = 0,0
20. = 10,0
21. = 25,4
22. = 98,2

But still, its doing some overshoot, if the first setpoint is 65 degree, it goes up till 68 or 70 degree.
Which parameters and how do we need to chenge them, to make it slower, but more accurate?
Pixsys tecnico 6
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Re: [ATR621] PID regulation

Post by Pixsys tecnico 6 »

Hi,
What type of ATR621 are you using? Which relay are you using for heating?
You can try to decrease the parameter number 23.[Tc], but it necessary use a SSR output if you want more accuracy.

Best Regards.
user7736
Posts: 19
Joined: 25/02/2014, 13:37

Re: [ATR624] PID regulation

Post by user7736 »

We are using ATR621-12ABC
Sorry, i forgot to answer this: We are using already SSR output.
23. = t.c. = 1
Pixsys tecnico 6
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Joined: 12/09/2016, 14:49

Re: [ATR624] PID regulation

Post by Pixsys tecnico 6 »

Hi,
did you try to enable the Autotuning? 11.[tune] = "Auto".

If Autotuning does not fully meet your setting, the PID parameters must be set manually, but the PID parameters depend on the composition and structure of the oven.

Best Regards.
user7736
Posts: 19
Joined: 25/02/2014, 13:37

Re: [ATR621] PID regulation

Post by user7736 »

Hi.

yes, after Auto TUNE, its not satisfying our process, so we started to change PID parameters manually.
And when we increased tD parameter, overshoot was already gone, of course its now slower, but more accurate.
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