PID issue

WaltE99

WaltE99

Fickle Bastard Blades
Joined
Oct 5, 2015
Messages
179
So I just got a PID controller in along with a SSR and a Pt100 "thermocouple" to connect to my shop toaster oven. Since I am not electrically inclined and the directions were incomplete/incorrect, I had issues from the beginning. Many thanks to Pleasanthill for helping me out with the wiring and the thermocouple connection. Today I was curing some handle material and stuck an oven thermometer in my toaster oven. The PID was set to 195 degrees. The oven thermometer read almost 250, about 50 degrees higher than the PID reading. BTW, I did change the Input setting from the default K type to Pt100.

I went to the store and purchased another oven thermometer and took it and the one from the shop and put them in my kitchen oven at 400 degrees. After about 20 minutes, both thermometers were pretty close to 400. So I took them back out to the shop oven and jacked the PID up to 400 degrees. When the oven heated up to that temperature based on the PID reading, I checked the thermometers and both read about 450 degrees, again about 50 higher than indicated.

I don't even know what to ask other than for any ideas anyone may have as to how to fix the issue. My initial thought is just to buy a K type thermocouple and change the PID Input setting back to K.

Thanks in advance for the help!
 
For a rough check, put the RTD (Pt-100) in a pot of boiling water to check temp, then perhaps a bath of slush ice/water to check there. You know the water is going to be +32ºF in slush water/ice and 212ºF in boiling water, corrected for your altitude above sea level.
 
I sent you a PM I'll post what I sent you here as well. but you can also adjust the display in the PVF setting. If you adjust it check a few other temps to verify. Checking known temps as Ken suggested would be good points to use.

Didn't have time last night to get back to you, the engine damage is worse than I was hoping. Not something that can I can fix without removing and tearing the entire engine down. So looks like I'm engine hunting. Gonna be cheaper than taking it apart and fixing.
 
pleasanthill said:
I sent you a PM I'll post what I sent you here as well. but you can also adjust the display in the PVF setting. If you adjust it check a few other temps to verify. Checking known temps as Ken suggested would be good points to use.

Didn't have time last night to get back to you, the engine damage is worse than I was hoping. Not something that can I can fix without removing and tearing the entire engine down. So looks like I'm engine hunting. Gonna be cheaper than taking it apart and fixing.
Click to expand...

OUCH! Sorry to hear the truck is worse than you thought. Thanks to both you and Ken. I'll try those things. I messaged the seller to tell her about the "probrom" and she sent me the Pt100 wiring info. I wanted to choke her....why didn't you send that with the package. Might have saved a couple days of researching. Sheesh
 
Look at the other section where it talks about the PVF setting. "

If all above mentioned is collect , pleaase use parameter PVF to modify."
 
OK boys, you ain't gonna believe this s**t! I have not 1 but 2 oven thermometers that are off approximately 50 degrees in the same direction. PID ice bucket challenge read 34 (I really had to much water to ice so it wasn't really a slush) and the boiling water to about 214. At most, the PID may be out a couple of degrees. Now to test my indoor oven which we THOUGHT was about 25 degrees high but must actually be about 25 degrees low.

Thanks for the help! Now I have to tell Phyllis ("probabry" not her real name;) that it was my fault after giving her grief for not sending the thermocouple wiring info to start with. Oh well.
 
Before you start adjusting the PvF, make sure all other things are right:

Make sure all parameters are speaking the same language. F/C, type K/J/RTD, etc. Make sure the TC is the type selected. Make sure everything is connected to the proper places on the terminal board on the PID.

Make sure the devices used have the proper range. Many controllers, TCs, and readouts have set ranges. There is no point in using a readout that maxes at 1000 for a HT oven. Same for TCs - Don't use a 600F max TC for controlling your forge. Generally, the heavier the wire size in a TC, the better it will work and last. Use 8-10 gauge TCs for ovens and forges. Use a TC sheath for a forge. Don't expect good results by pushing a device to its limits. I use 75% of max rating as the working upper range. Your most accurate results will be using a device in its mid range.

Most knifemaker TCs are type K, J, and RTD pt-100. There are many other types, but these three are what we will see 99% of the time.

Type K and J Tcs use two slightly different alloys in each wire, and the junction causes a temperature variable voltage output. All wiring in the cu-ircuit needs to be done in the same alloy as the lead it is connected to. Using speaker wire or lamp cord to connect a TC will cause an error in the reading.

RDTs (Resistance Temperature Detector) are normally lower temp devices. They are a very accurate variable resistor that puts out a resistance change relevant to the temperature of the device instead of a voltage change like type K/J TCs. Platinum is used because of its resistance properties ( pt-100). Many of the issues with type K/J TCs are eliminated by RTD. Observe the lead color code in connection, and all procedures to prevent resistance issues in connections and extension wiring. The main caveat is to avoid adding any resistance to the circuit. The RTD has three wires to connect. It has to go to an RTD location on the PID. If the PID has TC terminals as well as RTD or PT-100 terminals, use the RTD ones. If the PID has only one TC spot, it will have two + and two - terminals. There will be a resistor image that represents the RTD and how it connects. The wires are usually one red and two black (or two white). The red wire is called lead "A", and goes to the positive side RTD connection. There are usually two of these terminals, because some RTDs have four wires ( two A and two B). If using only one red "A" wire, jumper the two terminals together. On a PID I looked at these terminals were #10 and #11. Some PIDs have these terminals internally or externally jumpered already. The two black (or white) wires are called leads "B", and go to the two negative terminals ( sometimes labeled -). On the PID I looked at, these were terminals #12 and #13. It does not matter which black wire goes to which of these terminals.

Make sure all polarity is observed ... Repeat - Make sure all polarity is observed! In a TC circuit everything is polarized.

On type K or J TCs, use the appropriate type TC connector wires ( often designated EXK, EXJ, etc.). It usually comes as a two strand cable. Observe the wire polarity ( yes, the wires are polarized!). Use a TC connecter terminal to connect the TC wires and TC, and type K/J plug/socket for the other end.

On an RTD TC (pt-100), the connecting wires from the RTD to the PID need to be low impedance and the exact same length. All joints should be hard wired on a terminal board with cleaned wires. Avoid twist connections, plugs, sockets, etc. Again, observe proper wiring connections to minimize resistance. The best wire to use is called EXGG three conductor. It is a high temp glass coated three wire RTD cable.

Run the PID for at least an hour to allow it to "learn". You can switch the logic mode in some PIDs to make them more accurate ( fuzzy logic).

If all else fails, then adjust the PvF. Use known temps to calibrate. Boiling water (212F) and ice slush (+32F)are exact references for out purposes. The boiling point lowers by roughly 2 degrees per 1000 feet of altitude. If you live at 5000 feet, water boils at about 202F. The freezing point also rises as altitude increases, but the difference is small, so just use +32F or 0C for an ice bath.
 
Stacy E. Apelt - Bladesmith said:
Before you start adjusting the PvF, make sure all other things are right:

Make sure all parameters are speaking the same language. F/C, type K/J/RTD, etc. Make sure the TC is the type selected. Make sure everything is connected to the proper places on the terminal board on the PID.

Make sure the devices used have the proper range. Many controllers, TCs, and readouts have set ranges. There is no point in using a readout that maxes at 1000 for a HT oven. Same for TCs - Don't use a 600F max TC for controlling your forge. Generally, the heavier the wire size in a TC, the better it will work and last. Use 8-10 gauge TCs for ovens and forges. Use a TC sheath for a forge. Don't expect good results by pushing a device to its limits. I use 75% of max rating as the working upper range. Your most accurate results will be using a device in its mid range.

Most knifemaker TCs are type K, J, and RTD pt-100. There are many other types, but these three are what we will see 99% of the time.

Type K and J Tcs use two slightly different alloys in each wire, and the junction causes a temperature variable voltage output. All wiring in the cu-ircuit needs to be done in the same alloy as the lead it is connected to. Using speaker wire or lamp cord to connect a TC will cause an error in the reading.

RDTs (Resistance Temperature Detector) are normally lower temp devices. They are a very accurate variable resistor that puts out a resistance change relevant to the temperature of the device instead of a voltage change like type K/J TCs. Platinum is used because of its resistance properties ( pt-100). Many of the issues with type K/J TCs are eliminated by RTD. Observe the lead color code in connection, and all procedures to prevent resistance issues in connections and extension wiring. The main caveat is to avoid adding any resistance to the circuit. The RTD has three wires to connect. It has to go to an RTD location on the PID. If the PID has TC terminals as well as RTD or PT-100 terminals, use the RTD ones. If the PID has only one TC spot, it will have two + and two - terminals. There will be a resistor image that represents the RTD and how it connects. The wires are usually one red and two black (or two white). The red wire is called lead "A", and goes to the positive side RTD connection. There are usually two of these terminals, because some RTDs have four wires ( two A and two B). If using only one red "A" wire, jumper the two terminals together. On a PID I looked at these terminals were #10 and #11. Some PIDs have these terminals internally or externally jumpered already. The two black (or white) wires are called leads "B", and go to the two negative terminals ( sometimes labeled -). On the PID I looked at, these were terminals #12 and #13. It does not matter which black wire goes to which of these terminals.

Make sure all polarity is observed ... Repeat - Make sure all polarity is observed! In a TC circuit everything is polarized.

On type K or J TCs, use the appropriate type TC connector wires ( often designated EXK, EXJ, etc.). It usually comes as a two strand cable. Observe the wire polarity ( yes, the wires are polarized!). Use a TC connecter terminal to connect the TC wires and TC, and type K/J plug/socket for the other end.

On an RTD TC (pt-100), the connecting wires from the RTD to the PID need to be low impedance and the exact same length. All joints should be hard wired on a terminal board with cleaned wires. Avoid twist connections, plugs, sockets, etc. Again, observe proper wiring connections to minimize resistance. The best wire to use is called EXGG three conductor. It is a high temp glass coated three wire RTD cable.

Run the PID for at least an hour to allow it to "learn". You can switch the logic mode in some PIDs to make them more accurate ( fuzzy logic).

If all else fails, then adjust the PvF. Use known temps to calibrate. Boiling water (212F) and ice slush (+32F)are exact references for out purposes. The boiling point lowers by roughly 2 degrees per 1000 feet of altitude. If you live at 5000 feet, water boils at about 202F. The freezing point also rises as altitude increases, but the difference is small, so just use +32F or 0C for an ice bath.
Click to expand...



Stacy, unless he was sent something (TC) other than what he was told, It's a RTD PT-100 probe. The input selection has been switched and the wires are all the same length (pre-assembled length how it was sent to him) Only wire used on the TC not from the seller is the jumper wire connecting the 2 terminals for the type of TC (good quality 12 or 14 gauge strand copper wire).I know its set to F for temp reading type. I actually went to his house and helped him get the SSR side right. When I bought mine it was pre-configured and tested by the seller, so I didn't think to check the input selection while I was there and being set at default to K or we prob would have had it sorted out before I left. The TC connections are the connections that came on the TC going straight to the PID, so it shouldn't be a wire issue. 99.99% sure on this probe as long as (in his case blue) the blue wire is right the other 2 red wires are not polar and can interchange. Correct me if I'm wrong. I'm pretty confident that at where he's at, the PvF is where he's going to have to adjust it. It's on a toaster oven so that should give you an idea as to what it will be used for.
 
Sounds like you have done all the checks I mentioned. In that case the PvF is where to go. BTW, what PID did he get? Some have programming issues and the PvF can not be set to a negative amount.

My post was mostly as a reference to people not familiar with PID and TC connections. I will likely stick this thread in the PID sticky.
 
Stacy E. Apelt - Bladesmith said:
Sounds like you have done all the checks I mentioned. In that case the PvF is where to go. BTW, what PID did he get? Some have programming issues and the PvF can not be set to a negative amount.

My post was mostly as a reference to people not familiar with PID and TC connections. I will likely stick this thread in the PID sticky.
Click to expand...

I was just referencing what he/we checked/did and has as far as wiring.

The Model number on the sticker says MyPin TA7-SNR-SSR

It's a slightly larger unit than the usual 2x2 unit people use. It has 18 numbered slots, but only has actual connections for 1-4, 7, 8 and 10-13 (1,2 120v input) (3, 4 alarm 1) (7, 8 SSR) (10-13 TC)

Any idea what the SNR stands for in the model number? Just curious. The SSR is obvious.
 
It was the MyPin TA4 PIDs that had bugs in the programming and other problems. They had to reprogram a lot of them at the factory, but many got out with the defects in the program. The PvF not being able to be set to a negative number was one problem. I hope the newer PIDs have the bugs fixed.

Google "MyPin PvF problems" and you will see a lot of threads and posts on the bugs and problems with them.
 
You must log in or register to reply here.
Back
Top