[ATR120] Temperature jumping

user9620 · Post by **user9620** » 17/03/2015, 16:04

hello.
My ATR120 temperature is jumping constantly with 10 degrees of difference every few seconds.
I would like to know if it is possible to solve the problem with the PID regulation or in other way or on the contrary the ATR120 is broken.

Thank you very much.

Post by **Pixsys tecnico 1** » 17/03/2015, 16:10

Hi,
if you are using a TC input, try to unplug the probe and shortcircuit the analog input. If the temperature is instable again, the regulator is broken.

user9620 · Post by **user9620** » 17/03/2015, 16:17

Hi.

I am using a Pt100... I have to shorcircuit the three inputs???

Regards.

Daniel.

Post by **Pixsys tecnico 1** » 17/03/2015, 16:37

No, in this case is difficult to understand what is wrong. Can you try to replace the PT100? The reading is always instable or only when output switches on and off?

user9620 · Post by **user9620** » 17/03/2015, 16:42

My ATR120 is controlled by a Pt100 probe.

The problem is that it has a big fluctuation of 10 degrees difference in few seconds. The Pt100 probe is ok.

I want to know if I can regulate this in some way or the ATR120 is broken.

Regards.

Daniel.

Post by **Pixsys tecnico 1** » 17/03/2015, 16:44

The reading is always instable or only when output switches on and off?

user9620 · Post by **user9620** » 17/03/2015, 17:02

It is all the time jumping in any case.

Post by **Pixsys tecnico 1** » 17/03/2015, 17:18

If the probe is ok and the process is always instable, I think the regulator is broken.

user9620 · Post by **user9620** » 18/03/2015, 16:12

Today, everything has changed.

The temperature only fluctuates a couple of degrees.

But I measure with the thermometer 55C, I measure in the Pt100 resistance + 122ohms, that means 122-100=22x3= 66C and on the ATR120 I read 79C

Apart from the probe... could I correct this difference with the PID??

Thank you very much.

Post by **Pixsys tecnico 1** » 18/03/2015, 17:01

If you want to correct the reading value you can work ok [cao] and [cag] parameters.

user9620 · Post by **user9620** » 14/04/2015, 13:54

Hi. yes, you were right, the temperature jumps with such difference temperature values when the output is switching on and off... how can I solve it??

Thank you.

Post by **Pixsys tecnico 1** » 15/04/2015, 8:48

Hi,
try to unplug outputs form the regulator. If temperature jumps anyway, the problem is in the regulator. If themperature is constant instead, the problem is in the heater element (maybe too "strong"), so Tuning function can help.

user9620 · Post by **user9620** » 15/04/2015, 13:20

Hi.

I don't understand about the heater element. The output is connected to the contactor coil then the current cannot be high.... the output is not connected to the heater.

Regards.

Post by **Pixsys tecnico 1** » 15/04/2015, 14:10

If you disconnect the output, and when relay goes on and off the temperature jumps, the problem is in the regulator (maybe power supply failure) because no "power output" can modify the process.

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