Mypin TD4 malfuncton?

[GutoSchettini]

Dear all,

I'm a beginner in electric brewing... I bought a RIMS tube (Brewhardware), than the PID (Mypin TD4-SNR+SSR) and the temperature probe (RTD PT-100, 3 wires).

After puzzling for a while (reading forums & watching youtube movies), I wired everything in the right way. However, playing with the PID and temperature, I noticed that when the PV is lower than SV, the OUT1 led (and the one in the SSR too) flashes instead of be continuously 'on'. Also, the autotunning takes a lot of time to finish (>20 minutes).

Definitively, it doesn't behave like the one showed in this film
[ame]https://www.youtube.com/watch?v=KFVcrtQ_pdQ[/ame]

My conclusion is that I got a defective unit and will return it. But I would like to hear from you who has experience with this controller. Has anyone had a similar problem?

Thank you!

Guto

 

[augiedoggy]

How much lower? the pid doesnt work like a thermostat. It doesnt just stay on until the setpoint is reached and then turn off... When its autotuned correctly (with the pumps running at the same flow and the same amount of liquid that you'll roughly be using) It will act very strangely and likely overshoot its target as it learns and tries to basically recalculate new P, I and D values.. and then when your brewing with it as it get closer to the setpoint the output begins to flash and stay on less consistently because its trying to maintain and not overshoot the temps.. also if your constantly using a different flow rate your pid tuned values will be off.

If it didnt autotune correctly it can act strange too by either under shooting or more likely overshooting the setpoint and fluctualting up and down instead of maintaining the same temp..
Honestly If you got a bad td4 you would be the first Ive seen.. You cant really compare the pid being used for that little pot of alloy vs a rims with liquid passing by the element and probe. Hes also sped up that video feed as well so.

 

[JONNYROTTEN]

The lights are supposed to blink in sync in the pid and SSR. For what its worth I didn't even bother running the auto tune on my new PID. I found its easier with less to worry about just to dump the grain at around 156 deg. The temp drops with the cooler grain to around 153. Then I just cover the pot and shut off the power to the element. In 60 minutes I only drop maybe 4 deg and most of that is towards the end. Its been said here many times its believed most if not all conversion happens in the first 5 or ten minutes so if the temp drops a little over an hour it doesn't matter.....hasn't effected my beer in the least not using the PID to maintain exact temps for an hour.

 

[RichBenn]

#1 - that video is using a thermocouple, not an RTD. Just thought I'd mention that as its common to get the wiring on these wrong. You should have three wires, and you need a jumper on the TD4 as all RTD inputs are really 4-wire RTD capable.
#2 - TD4s do not autotune well, at least for an HLT. Maybe it's better for a RIMs. If you search around(or ask nicely), AuggieDoggy has posted some manual tuning parameters that only overshoot a little. It's still not ideal in my opinion, but may work better for a RIMS tube. (I am seriously considering buying an Auberins for my HLT).
#3 - After you manually tune the TD4 to AuggieDoggy's recommendation, you should see solid on ramping up, then flashing when it gets close.

Hope one or more of these thoughts help.

 

[augiedoggy]

Reducing the "I" value helped the most with the overshoot if I remember right... I did autotune my rims though and it dramatically helped with controlling temps..
You don't need the jumper for the 3 wire pt100 it works with or without it actually.

 

[GutoSchettini]

Thank you all!

My first time using the forum too. Bit confusing the options how to answer

Thank you all.

Augiedoggie:

Very nice control box you have. That's my goal... meanwhile, my first step is to learn how to make the TD4 works!

I did the test like this: I set SV at 68 oF. Put the temperature probe in a cup with water and ice, the PV dropped to 40 oF, and the OUT1 led keep flashing. Never turned 'on' continuously. It keep flashing about once per second. It is also funny that when I hold the temperature probe in my hand, the PV rise up to 86 oF, and the led keep flashing. Stop flash after a few minutes... very weird!

Please, could you give me the P, I and D values you have in you PID? I'll do like Richbenn suggested, and see what happens.

Jonnyrotten:

I'm making 2 gallons batches, no sparge. So, as I have less mass (water+grains) in the mash tun (one of these orange HomeDepot cooler), the temperature drops about 7 oF in 1 hour. Anyway, the point is how to make the controller work!

Richbenn:

The temperature readings are ok. I cross check with my digital brewing thermometer. The difference is about of 2 oF. I didn't change the offset yet.


How long it takes to run the autotunning?

Thanks again!

Guto

 

[GutoSchettini]

Now it is doing what was expected!

I change the PID settings, as you recommended.

P: didn't change
I: was 240, I change to 100
D: was off, I change to 1

Then, again, testing the operation around 70 oF, I run the auto-tunning again. It took 10 minutes to run. After, the parameters change to:

P: 0.1
I: 20 (is the same of the SV (I'm using oC). Coincidence?)
D: 0.5

Voulá. The OUT1 led stays 'on' when the temperature drops about 1 degree below the PV, and turns 'off' when the temperature reach the PV. It flashes a couple of times during the transitions, and that's all.

Thank you again! Next step, test in the RIMS.

Guto