Mypin ta-4 readings way off

[Syncman]

Basic 1x 1400w, 120V element, ktype thermocouple, 5 gallon pot, Mypin ta-4, and ssr output. Playing around with plain water to test this thing, but my temp is 14 degF off. Set at 156, holds around 155 to 157 as shown on PV output, on Mypin, but 2 separate thermometers show 142F. Swapping leads on TC the reading goes to 32 and just sits there, so I believe do have it connected right [pins 7 and 8]. Autotune does not correct this, so any help?

 

[itsnotrequired]

do you have the pid set to tc mode (as opposed to rtd)?

 

[WrQth]

Change the temp "Offset" option in the PID controller to compensate assuming wiring and probe type is correct

 

[Syncman]

Thanks for the "offset" advice. My probe was showing 46F in a cup of ice and water which should be exactly 32. Set offset at 16 and now its fine. Found this because chinglih instructions read like 'super monkey death car"

[ame]https://www.youtube.com/watch?v=-cKa_EWRIQY[/ame]

 

[augiedoggy]

If you do a search here (or look a few lines down in the electric section threads you will find this thread with better instructions linked for the Ta4. along with another thread from yesterday... https://www.homebrewtalk.com/showthread.php?t=572582 Im pretty sure there are settings for multiple TC types (examples would be J or k type) and One more question? Did you alter the wiring at all from the sensor to the pid like add longer wiring or connectors? Im pretty sure special wire is needed and changing the length effects the reading... Yet another reason RTDs are the more popular choice.. I never had good luch with the TC sensor I tried myself..

good luck with your setup!

 

[Syncman]

Did read thru that, but that everything I see on interwebs, is how to set up the PID. not much out there for when things dont pan out like you expect. There are so many variables and options with this thing that I guess its not possible to list them all. Like the "offset" advice above. Once someone can point you in the right direction, the info is easy to find. The k type I have is unmodified, but still giving readings way off [14deg]. Set the "offset" and now its spot on.

 

[pmaster]

Also had a tough time setting up mine. You should run it on auto-tune to get the proper PID parameters (takes about 15min). Don't forget to have a default value set for P, I,D before launching auto-tune. If one of the parameters is to OFF I think it may not properly auto-tune

 

[augiedoggy]

Also had a tough time setting up mine. You should run it on auto-tune to get the proper PID parameters (takes about 15min). Don't forget to have a default value set for P, I,D before launching auto-tune. If one of the parameters is to OFF I think it may not properly auto-tune

It should autotune regardless... When doing an autotune it adjusts new P, I and D values... all at the same time.

I know it may not be the written in the easiest to understand manner but the offset adjustment is in the mypin instructions because thats were I found it when I had to adjust mine... (I only speak English myself so the "Engrish" instructions were a challenge at times)

 

[acidrain]

I found the auto-tune feature of the Mypin PID's to be completely worthless.
After some basic info on manually adjusting and quite a bit of trial and error, I am dialed in with zero overshoot. It wasn't that hard, and my numbers are miles away from the auto-tuned numbers, which were different every time I tuned it.

 

[augiedoggy]

Autotune worked for me but I use 3 td4's.