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[Dolle]

When do the setting AT function, the device contineously keep flashing "AT-actual temperature".
It never stops flashing.
What to do?
Best regards, John Steffensen, Denmark

[Sharron]

Thanks for posting your question here. Flashing "AT" means the controller is running auto-tuning. The controller will bring temperature to its set value (SV, target temperature) in on on/off mode, i.e., raise the temperature above SV, and let it drop below SV, and repeat this a few times to figure out a set of suitable PID settings for your system.

So when you see AT flashing, and the probe reading is below your set value, then you should be able see OUT light on, and your cooker should be heating at this moment. If somehow the probe reading never reaches your set value, the auto-tune will never end. Please make sure you plug the cooker to the controller, and put the probe in the cooker with some water. And let us know how it goes.

[Dolle]

Hi. Thanks for assisting me.
I am running PID control.
Have a pot with 8 liters of water, heating plate 1500W, setpoint 30 degree Celsius.
Running Auto tune function, is running now for approx 20 hours, and still flashing.

Now the problem is, that the temperature in the water goes up to 36 Celsius, after switch off (Output OFF)
How to prevent it happening?
Maybe, I should have more patience, as long Auto tune still running/flashing?
Best regards, John from Denmark (The last Viking!)

[Dolle]

Hi.
Just needed some more patience.
Controller is running perfect and keep the temperature on 30 C.
Great.
John Steffensen

[Dolle]

I would like to learn about the temperature control for this device.
I managed to have the controller run perfect with setpoint 30 degree Celsius.
Later, I changed the setpoint to 32 degree Celsius, and then it was not able to control the perfect way, as when the setpoint was 30 degree celsius.

Should I run a Auto tune test every time I change the setpoint? I am a hobbyist , making cheese. For this purpose, I have to heat up milk with different temperatures. (Hest up slowly is mandatory)

Or should I skip PID control, and use the Heating mode?
If Heating mode is to be used , then please advise all Parameter settings for Heating mode, to get the best control.
Thanks for assisting me.
Best regards, John Steffensen, Denmark

[Sharron]

Sorry for the delay in getting back to you on this thread.

Regarding the auto-tune. When running the auto-tune at 30 degree C in water, the controller will be working in on/off mode. When temperature is less then 30 C, the controller will send power, and OUT indicator should be on; when temperature is greater than 30 C, no output and OUT indicator should be off; and when the temperature drops below 29 C (there is 1 degree hysteresis), controller will send output again and the OUT indicator will be on. The controller will do this three times during auto-tuning. Heating the water above 30 C is relatively fast, but wait the temperature drop back below 29 C could take a long time since it is a passive cooling process. It depends on the heat insulation of your cooker and the ambient temperature.  

Usually you will need to run auto-tune again if you have two very different set values (SV). But between 30 C and 32 C, I don't think you need to run auto-tune again.

By the way, if the set point is very close to the ambient or the room temperature, it can be difficult for the controller to stabilize the temperature. Maybe after powering on the cooker for one control cycle, 20 seconds, the temperature was already above your set point.

Auto-tune may not necessarily give you a good P, I, and D setting. Sometimes user have to manually tune these parameters. You can try using "heating" mode, maybe it can give you a good enough result.

[Sharron]

Now the problem is, that the temperature in the water goes up to 36 Celsius, after switch off (Output OFF)

First thing to check is the synchronization between the OUT indicator, the relay action (you can hear clicks) and the actual power output to the cooker. If the OUT light is off, but the heating element can still get power, probably the relay is stuck due to overheat. If they are all synchronized, its not an hardware issue. If at 36 C the OUT light is still on, it is a PID parameter tuning issue.  

Could you check our P, I, and D values and post them here?

[Dolle]

Hi.
I think, I will only use the unit as a PID controller. There the controller is working perfect. (For example SV 32 deg. celsius)
Using it for either cooling control, or cooking control, I find the controller to be of low/no use.

Because:
Using it  as a cooker control, the temperature (in the water) will continue to rise/go up  after setpoint has been reached due to the cooking plate is still heating up the water.
I am not able to find out, how to set the controller to avoid this.

Using it as a cooling control. the temperature ( in the refrigerator) will continue to drop down after the setpoint has been reached, due to the evaporater will still cool down the air in the refrigerator.
I am not able to find out, how to set the controller to avoid this.

Further, I am not able to understand in details the meaning of all the parametersettings, and how to do those settings. It is too complex for me to understand.
What to do?
Best regards, John Steffensen, Denmark

[Sharron]

Using it  as a cooker control, the temperature (in the water) will continue to rise/go up  after setpoint has been reached due to the cooking plate is still heating up the water.
I am not able to find out, how to set the controller to avoid this.

Using it as a cooling control. the temperature ( in the refrigerator) will continue to drop down after the setpoint has been reached, due to the evaporater will still cool down the air in the refrigerator.
I am not able to find out, how to set the controller to avoid this.

Is the OUT indicator still on when temperature reaches your set temperature? If so, the controller is working correctly as it is supposed to. Try to place the sensor a little closer to the heat source or try to circulate the water/air may help.  

But in "heating" or "cooling" mode, the controller is working in on/off control mode, which is known to have some fluctuations.  

Further, I am not able to understand in details the meaning of all the parametersettings, and how to do those settings. It is too complex for me to understand.

Which parameter(s)? We can try explaining it here. Thank you.