# How to prevent overshooting with ITC-100VH **URL:** \ **Category:** Questions & Answers\ **Tags:** smart-controller\ **Created:** [August 3, 2023, 4:07pm UTC](https://community.inkbird.com/t/how-to-prevent-overshooting-with-itc-100vh/75247 "2023-08-03T16:07:00Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Roland](https://avatars.discourse-cdn.com/v4/letter/r/3ab097/32.png) [@Roland](https://community.inkbird.com/u/Roland)\ **Post date:** [August 3, 2023, 4:07pm UTC](https://community.inkbird.com/t/how-to-prevent-overshooting-with-itc-100vh/75247/1 "2023-08-03T16:07:00Z")
Hello all, this is my first post and I will start with a first question. I try to use the Inkbird ITC-100VH to control the temperature in an incubatore. In combination with the Inkbird I use a SSR. The heater has a power of about 60 W. The temperature sensor is a K-type. At the beginning I started a self-tuning. Unfortunately, I do not have a graphical representation of the temperature curve. But probably you can see from the parameters that the self-tuning has determined, how sluggish and how the reaction of the controlled system is. I set the temperature to 30 °C and the temperature in the incubator overshoots by about 2 °C. Here are the parameters (I hope these are the most important) that the self-tuning has determined: M50 = 71 P = 3066 t = 264 Ctl = 48 Sn = 0 (K type) Which parameters should I change and how, so that the overshoot goes back to 0 if possible? I am aware that the time needed to reach the set point will increase. I have tried to double or halve the parameters M50, P, t and Ctl one by one. I can’t get an idea of what I should reasonably change. Can someone please help me with this? ---
**Author:** ![Tania](https://yyz1.discourse-cdn.com/flex031/user_avatar/community.inkbird.com/tania/32/88_2.png) [@Tania](https://community.inkbird.com/u/Tania)\ **Post date:** [August 7, 2023, 6:32am UTC](https://community.inkbird.com/t/how-to-prevent-overshooting-with-itc-100vh/75247/2 "2023-08-07T06:32:01Z")
Hello, Please set Ctl to 0 and then execute the self-tuning function. If the temperature still fluctuates slightly, please repeat the self-tuning several times and it will tend to be accurate. Can it work? ---
**Author:** ![Roland](https://avatars.discourse-cdn.com/v4/letter/r/3ab097/32.png) [@Roland](https://community.inkbird.com/u/Roland)\ **Post date:** [August 9, 2023, 8:52am UTC](https://community.inkbird.com/t/how-to-prevent-overshooting-with-itc-100vh/75247/3 "2023-08-09T08:52:38Z")
Thank you so much, Tania for your recommondation! I tried it and it might be slightly better. The overschoot now is 1.2 °C. When I open the door and wait until the temperature is lowered to 28°C and close then the door again the heater starts to heat the incubator. For my feeling the heater should stop heating when the temperatur reaches 28.5 °C. Then it should wait for several minutes and if the temperature will not increase - lets say for 30 - 40 seconds then a more or less short time the heater should be powered on and so on until the setting value has been reached. I changed the sensor type again to PT100 because the bridge (4-5) was closed. The paramters are now: M50 = 136 P = 5036 t = 277 Ctl = 40 Sn = 21 (PT100 type) What do you recommend what parameter should I now adapt to come in the right direction? An additional question: can I see whether the output is pulsing? Or turns the output LED on when the output goes lets say to 50% (less than 100%)? ---
**Author:** ![Tania](https://yyz1.discourse-cdn.com/flex031/user_avatar/community.inkbird.com/tania/32/88_2.png) [@Tania](https://community.inkbird.com/u/Tania)\ **Post date:** [August 11, 2023, 2:28am UTC](https://community.inkbird.com/t/how-to-prevent-overshooting-with-itc-100vh/75247/4 "2023-08-11T02:28:39Z")
Please reduce the value of Ctl setting according to the actual temperature change so that it achieves the desired effect. For Ctl setting, please refer to section 6.10. > **[ITC-100\_Manual\_V1.pdf](https://drive.google.com/file/d/1aMGEjKl_iInLL6hb56o-1Vur1b1JJlGG/view)** > > Google Drive file. The output LED indicator of ITC-100VH is synchronised with the output. ---
**Author:** ![Roland](https://avatars.discourse-cdn.com/v4/letter/r/3ab097/32.png) [@Roland](https://community.inkbird.com/u/Roland)\ **Post date:** [August 12, 2023, 2:19pm UTC](https://community.inkbird.com/t/how-to-prevent-overshooting-with-itc-100vh/75247/5 "2023-08-12T14:19:55Z")
Thank you again Tania! I tried a new approach. I bought a new PT100 with a tiny sensor which has a very small mass. I started the self-tuning and now the controller works as expected with no overshoot. So the result is: the PT100 was too sluggish! Maybe that other guys have the same problem. This could be one way to solve it. ---
**Author:** ![Tania](https://yyz1.discourse-cdn.com/flex031/user_avatar/community.inkbird.com/tania/32/88_2.png) [@Tania](https://community.inkbird.com/u/Tania)\ **Post date:** [August 14, 2023, 2:15am UTC](https://community.inkbird.com/t/how-to-prevent-overshooting-with-itc-100vh/75247/6 "2023-08-14T02:15:54Z")
Thanks for sharing 😄