PID reading the same temp...always Whats wrong ?

[Mike Vogan]

Hey group Thought maybe ya'll could help me on this problem I have the Mypin T4 controller with the RTDPT100 temp probe This is a new probe and since its been in I have been having this problem I am assuming that the probe isnt right But the temp constantly reads whatever temp is on the PV and it wont change in an ice water bath or being heated Am I correct in my assumption that its the probe ? Or could it be something else I have switched wires til Im sick of looking at them Any ideas or just a plain simple solution would be very nice Thanx in advance for any help with this Before I forget this probe has 3 wires Black Red and Blue Where should they go and in what order ?

 

[doug293cz]

I suspect your probe may not actually be a PT100 RTD. RTDs typically have three wires, two the same color (because they are shorted together at the sensing element, and are interchangeable when connecting) and one a different color. Having 3 different color wires is a red flag. Do you have a link for the probe you bought?

Brew on

 

[Mike Vogan]

That makes sense I will try to find it

 

[Mike Vogan]

https://i.ebayimg.com/images/g/Q-EAAOSw4GVYQRGm/s-l1600.jpg Maybe this will help some This pic shows 2 blue connectors but mine has a black red and blue connector

 

[tracer bullet]

Do you have a link to the original item and its description, maybe the auction if you bought it on ebay?

 

[Mike Vogan]

I will look again and try to find that info Maybe this time I can get the whole thing

 

[Broken Crow]

I'm hesitant to suggest anything 'cause I've lost a lot of axons and miss things but:
If you have an ohmmeter; The resistance between 2 of the 3 wires will be the same no matter what temp the probe is, the resistance between 1 wire and the other 2 will change. So.. If you have a glass of cold or hot water, you can measure the resistance between each wire against each other wire, then drop the probe into something hotter or colder and measure again. The 2 wires that maintain the same resistance will be the 2 that should have the same colour connectors.

 

[doug293cz]

I'm hesitant to suggest anything 'cause I've lost a lot of axons and miss things but:
If you have an ohmmeter; The resistance between 2 of the 3 wires will be the same no matter what temp the probe is, the resistance between 1 wire and the other 2 will change. So.. If you have a glass of cold or hot water, you can measure the resistance between each wire against each other wire, then drop the probe into something hotter or colder and measure again. The 2 wires that maintain the same resistance will be the 2 that should have the same colour connectors.

Not quite. The resistance between to of the terminals (ideally the two same colored wires) should be 0 on your lowest resistance scale. The resistance between each of those wires and the other wire should be about ~100 ohms, but will change with temperature, according to the table below:

Brew on

 

[Mike Vogan]

RTD Pt100 Temperature Sensor Thermocouple 2M Cable 10CM Probe 3 Wires -50~400°C
(281581039687) Maybe this will work

 

[Mike Vogan]

Thanx Doug Will try that in morning If they arent that then its a bad probe ?

 

[doug293cz]

Thanx Doug Will try that in morning If they arent that then its a bad probe ?

Yup, if you don't get the readings in my post, the sensor is NG.

Brew on

 

[doug293cz]

RTD Pt100 Temperature Sensor Thermocouple 2M Cable 10CM Probe 3 Wires -50~400°C
(281581039687) Maybe this will work

Listing says it's a PT100, but ...

Brew on

 

[Mike Vogan]

But ? Its not...maybe

 

[doug293cz]

But ? Its not...maybe

If the resistance readings aren't as I described a few posts back, then it is either defective or not a PT100.

Brew on

 

[Broken Crow]

Not quite. The resistance between to of the terminals (ideally the two same colored wires) should be 0 on your lowest resistance scale. The resistance between each of those wires and the other wire should be about ~100 ohms, but will change with temperature, according to the table below:

Thank you! I'm still trying to get my brain back.
Mike Vogan ..It might cost more, but the Auber ones are pretty much guaranteed reliable:
https://www.auberins.com/index.php?main_page=index&cPath=20_15

 

[Mike Vogan]

Hey Doug Took those readings One was 111 and the other was 001 Those are in range I checked my setting on PID and it is on PT100 But now the temp says it is -403 and it wont go up or down or change I even put the probe in my skivvies to get the temp to change and nothing Cup of ice water and nothing Bad PID ? Heres what model I have Mypintd4 sn+ssr Dont know if this matters or not but thought I would throw it in there Did I leave out something on the model number ?

 

[tracer bullet]

One was 111 and the other was 001

You have 3 wires, and 3 combos, and will need 3 readings.

Red - Black
Red - Blue
Blue - Black

Attach your meter to those combos, set the meter to read resistance in ohms, measure and report back.

 

[Mike Vogan]

red-black 109.2
red-blue 109.2
blue-black 0.8

 

[doug293cz]

red-black 109.2
red-blue 109.2
blue-black 0.8

Based on those readings, I would say the probe is good. The implication then, is the PID is bad.

Brew on

 

[Mike Vogan]

Thats what I was afraid of So now its time to go shopping Thank you Doug and Tracer for your help Maybe I can get this thing working now

 

[Mike Vogan]

Before I go shopping Is there any suggestions on settings ?

 

[tracer bullet]

Hmm, I wouldn't replace the PID controller just yet. There's a decent chance the wires aren't in the right spot, or they are and there are some bad settings.

I'm not familiar with these guys, but I do know from a little PID experience they can be a little frustrating and not intuitive.

A little searching turned this up - maybe it'll help?

https://www.homebrewtalk.com/threads/mypin-td4-snr-with-pt100-wiring-diagram.627197/

 

[doug293cz]

Hmm, I wouldn't replace the PID controller just yet. There's a decent chance the wires aren't in the right spot, or they are and there are some bad settings.

I'm not familiar with these guys, but I do know from a little PID experience they can be a little frustrating and not intuitive.

A little searching turned this up - maybe it'll help?

https://www.homebrewtalk.com/threads/mypin-td4-snr-with-pt100-wiring-diagram.627197/

Yeah, the MyPin PIDs have an unusual connection scheme for PT100 RTDs. See below:

Your blue and black wires (both with blue terminal insulation) connect to terminals 7 & 10 (doesn't matter which is which) of the PID. Terminals 8 & 9 of the PID need to be connected with a jumper wire, and then the red wire connected to either terminal 8 or 9.

Do you have a copy of the MyPin User Manual?

Brew on

 

[Mike Vogan]

Thanx tracer and Doug I went and looked at the wiring diagram and it looks just like mine except for the hook up of the pt100 I was told once before to remove the jumper So now Im gonna put it back and see what happens That just might be the 403 error Will let ya know here in a while what happens Thanx again

 

[Mike Vogan]

I hooked the jumper back up and everything seems to be working Heres hoping it stays that way Thank you Doug and Tracer for all your help Believe me I was ready to throw this thing in the burn pile But now it appears to be working right so my feelings have changed

 

[tracer bullet]

Woohoo!

 

[doug293cz]

Glad we could help, and happy that you have things working correctly, finally.

Brew on

 

[Mike Vogan]

Have another question If this is the right place What kind of hoses is used on recirculating pumps on a still ? Would the stainless steel washer hoses work ?

 

[doug293cz]

Have another question If this is the right place What kind of hoses is used on recirculating pumps on a still ? Would the stainless steel washer hoses work ?

What will you be recirculating, at what temperature, and how much head pressure can your pump supply?

Brew on

 

[Mike Vogan]

it will be mash at around 190 degrees F

 

[day_trippr]

Gotta be silicone, probably reinforced...

Cheers!

 

[doug293cz]

it will be mash at around 190 degrees F

You got me curious now: how is this system configured, and how does it operate?

Brew on

 

[Mike Vogan]

Its pretty simple and basic First part of this year I thought I would like to try an electric still So Im converting my 15 gallon LP heated still over to electric If it dont work I will just put it back to LP burner It has 2 1500 watt electric heater elements, wired parallel , hooked to my PID with the probe in the side of the tank Which works perfectly by the way..after a test run with water I got to thinking yesterday that maybe I do need a recirculating pump to move the mash so it will heat more constant and even Thats one thing Im not sure about Thats it If theres anything else I need to know just tell me cause it wont hurt my feelings It took 45 minutes to heat to 190 With series wiring it would still heat but would take longer due to the fact the elements would be drawing half power

 

[doug293cz]

Why are you using a PID to try to maintain a constant temperature in the boiler? The boiling temp is fixed by the ratio of alcohol to water in the boiler. There is nothing you can do to change the boiling temp. The only ratio that boils at 190°F (87.8°C) is 22.5 ABV alcohol and balance water. Lower alcohol will not boil at 190°F, and higher alcohol will boil lower.

Normally boil vigor (which determines rate of vaporization and thus still output rate) is controlled with a power setting (manual mode on the TD4) not PID mode.

If you wanted to control the temp at some upper location in a fractionating column, then PID control is probably appropriate for that.

Finally, recirculation of a boiler is not necessary, as the convection currents during boiling stir things up very well. You might want to recirculate on heat up to boiling, if there is significant solids content in your wash. This is so that the solids don't settle on the elements and scorch during heat up. Once boiling, solids won't settle on the elements.

Brew on

 

[Mike Vogan]

Thanx Doug But you lost me at " why are you using " I didnt know changing over was going to be so confusing I dont understand all this I just might go back to the lp tank

 

[doug293cz]

Thanx Doug But you lost me at " why are you using " I didnt know changing over was going to be so confusing I dont understand all this I just might go back to the lp tank

Mike, you can use your MyPin TD4 in manual mode to set a specific power level that will give you the vigor of boil that you need to get the still throughput you want. Using PID mode to control a boil is hard enough when the boiling point is fixed, but if the boiling point is changing, like during distillation, it's pretty much impossible.

Running with the TD4 in manual mode is fundamentally the same as controlling the gas valve on a burner, except instead of turning a knob on a valve, you push up and down arrow buttons on the front of the TD4.

Brew on

 

[Mike Vogan]

Thanx Doug Now I believe I understand Think I will give it a try and see what happens Might still go back to the ol tried and true method