More PID wiring help needed

[waksupi]

I read so many threads here trying to figure out the wiring on this, I'm dizzy. Anyway, I'm not having good luck trying to do the job, and would like to ask for some help.

Lights come on, but the pot doesn't heat up. Here is how I have it wired at the time.

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Any suggestions?

[edctexas]

I can't make out your drawing as it seems too small for me to read. What PID unit do you have? You seem to show a relay and and what might be an SSR. Not sure why?

You can test the PID by replacing the POT with a medium power lamp (40-100W). Set the desired temp (the process variable) to just above room temp. The lamp should come on if the Thermocouple (TC) temp is below the desired temp. If you warm up the TC, the lamp should go out.

If the TC goes down in temp as you heat it, it is wired backwards. Reverse the leads and try again. These are all the simple tests for now. Could you make a bigger diagram and either PM me of post it?

Ed C Registered Professional Engineer MSEE and amateur radio op.

[waksupi]

I got the PID unit from Ebay. http://www.ebay.com/itm/261286976034. I think the seller may be a member here. PM sent.

[bangerjim]

EvilBay listing indicates this comes with a PT-100 RDT (100 ohm) NOT a type K T/C (thermocouple). Did you order it with a type K? You cannot just swap input devices without programming the ontroller differently.

An RTD has no polarity, a TC does.

[Retumbo]

From the uuuu on the read out I would say you have issues with the thermocoupel / rtd / thermistor

[Mike W1]

It looks like you have a Mypin TA4-SNR PID. Have one myself and your signal leads to the SSR should be 3&4 not 7&8. I just looked at the "instructions" from mine and they do show a Input Signal Selection parameter which your link said was preset for just that input. However I couldn't tell from a quick google search a whole lot that meant anything to me about a PT-Sensor. Obviously it's different than a K type but the Mypin drawing doesn't specify anything about hooking one up.

Double check that your parameter is set at PT100. Hook the TC to 7&8 and get your signal leads from the PID to the SSR on 4&5. Normally both the signal leads and the TC are polarity sensitive.

My guess is a PT-Sensor wires the same way as a K type.

Let us know if that helps. Your display looks to me like mine do when the TC isn't plugged in.

[Yodogsandman]

The PT100 probe should be hooked up differently. #7- Blue wire, #8- Red wire, #9- jumper wired to #8, #10- Blue wire.

Power in is shown as #1 and #2

Signal wires are shown on #3 and #4. The #3 (-) of the PID goes to the #4 (-) of the SSR. The #4 (+) of the PID goes to the #3(+) of the SSR.

I would also run the #2 wire on the SSR straight to the #2 "pot out" terminal of the terminal strip. But, I can't quite see which is + and -.

Check photo #3 as shown in the eBay listing for verification of wiring hook up locations.

[bangerjim]

It looks like you have a Mypin TA4-SNR PID. Have one myself and your signal leads to the SSR should be 3&4 not 7&8. I just looked at the "instructions" from mine and they do show a Input Signal Selection parameter which your link said was preset for just that input. However I couldn't tell from a quick google search a whole lot that meant anything to me about a PT-Sensor. Obviously it's different than a K type but the Mypin drawing doesn't specify anything about hooking one up.

Double check that your parameter is set at PT100. Hook the TC to 7&8 and get your signal leads from the PID to the SSR on 4&5. Normally both the signal leads and the TC are polarity sensitive.

My guess is a PT-Sensor wires the same way as a K type.

Let us know if that helps. Your display looks to me like mine do when the TC isn't plugged in.

A PT100 does NOT wire the same as a TC. And an RTD is NOT polarity sensitive.

Note the wiring diagram ON THE SIDE of the controller on the evilbay site.

100 ohm (and 1K ohm) platinum RTD's use 3 wires ( normally) NOT 2 as a thermocouple.
A t/c generates a millivolt DC signal dependent on temp. An RTD varies in resistance dependent on temp and does NOT put out a MV signal. The 3rd wire is for lead length compensation and accuracy. You can wire them up with 2 wires if you know which 2 to use!!! You will have ~100 ohms across two of them and a dead short across the other one to one of the others. Look at the wiring diagram.....it tells you all you need to know to be successful....along with which terminals to use.

I do this for a living.

bangerjim

[KenH]

Listen to Banger Jim - he does it for a living, and I did before retiring. No point in me writing any instructions, Jim has them written. I'm just confirming Jim's info.

Ken H>

[Mike W1]

I'd listen to Jim & Ken. I still don't know what's different about a PT-Sensor versus K type versus RTD but they apparently do. I'd think the side of your PID would have something similar to this, a photo of a K type.
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The Mypin "instructions" with my unit don't show the PT however I see the photo does!

[waksupi]

I specified the K type tc, so should be good on that account. I will need to absorb what you have all told mr and draw it out, to be surevI understand where I'm heading. Thanks for the input so far.

[bangerjim]

To determine if your thermal element is a PT100 RTD or type K TC, take your DVM and measure the resistance.

Disconnect the element B4 measuring to get a read of it rather than the input circuitry of the controller!

If an ohm or so (litterally a dead short), you have a type K TC.

If around 100 ohms, you have an RTD.

Simple as that. Do not be afraid of it....this is not rocket science....just simple common industrial electronic instrumentation.

I do not know if that vendor supplies 3 wire RTD's (they SHOULD!) but your DVM will tell you.



"A" and "B" are the RTD element (normally). "B' " is the lead length compensation. Note you have to short between 8 and 9.

banger

[Yodogsandman]

I have a MYPIN TA4 and hooked the type K probe wires to #7 and #8 on the PID unit.

[Mike W1]

Well I've learned a lot this time around thanks to bangerjim. Didn't even realize those things were available but it seems the original poster ordered the K type so it's 7&8 for the TC. But we've all learned how to tell the difference between the 2 types thanks to Jim!

Personally I was about to have withdrawal symptoms with the site closed down long as it was. Read that as not that much of a life!

[g5m]

I got the PID unit from Ebay. http://www.ebay.com/itm/261286976034. I think the seller may be a member here. PM sent.


It looks like those are prewired/connected from the listing.

[waksupi]

It looks like those are prewired/connected from the listing.

He just wired that up to show it working, it didn't come wired. I hope to get back to this project and get it figured out this week. I need a Wiring for Dummies book. One that says run THIS wire to THAT terminal. Too many conflicting things it seems. The squiggly little abbreviations and such in all the descriptions and instructions I have seen are totally worthless to me, as I don't speak that language any better than I do Mandarin Chinese.

[bangerjim]

He just wired that up to show it working, it didn't come wired. I hope to get back to this project and get it figured out this week. I need a Wiring for Dummies book. One that says run THIS wire to THAT terminal. Too many conflicting things it seems. The squiggly little abbreviations and such in all the descriptions and instructions I have seen are totally worthless to me, as I don't speak that language any better than I do Mandarin Chinese.


Unfortunately for you and others wanting to jump on the techno band wagon of digital process controllers, that "language" is the standard of today. Just follow the wiring schematics line by line if you do not have the technical prowess to inherently understand what it is for, and all will be good.

I started working with 3 mode process control technology back in the early 70's and learned the "PID" functions on pneumatic controllers! (try that on a simple tiny lead melting pot!) Then transitioned to analog controllers. And finally into the microprocessor-based controllers and PLC's of today.

Glad you got it up and running! Now you need to address the auto tune fuzzy logic to get the controller to function properly. If AT is turned on, the controller will self-learn over a period of time.

[g5m]

He just wired that up to show it working, it didn't come wired. I hope to get back to this project and get it figured out this week. I need a Wiring for Dummies book. One that says run THIS wire to THAT terminal. Too many conflicting things it seems. The squiggly little abbreviations and such in all the descriptions and instructions I have seen are totally worthless to me, as I don't speak that language any better than I do Mandarin Chinese.

Well, I can certainly relate to that! That's why I asked in one thread about which members here were making and selling pids.

[SWAGE-X]

Quick question about wiring PID's
Is there a "standard" or code as to the color of wire used in wiring a PID?
Or does everyone do their own thing/use what you have?
Thnx Lots
Bob

[waksupi]

Things seem to be working okay now, I may have some programming questions eventually. Apparently the instructions come in either Sanskrit, or ancient Greek, neither of which am I fluent in.

I do thank you guys for the help!

[bangerjim]

Quick question about wiring PID's
Is there a "standard" or code as to the color of wire used in wiring a PID?
Or does everyone do their own thing/use what you have?
Thnx Lots
Bob

Since you are NOT doing code wiring for commercial and or residential use, wire color is totally up to you. I always use different color for everything and never repeat the same color within the box or project, making tracing and hook-up a no-brainer. I have access to 14 different color scheme wire spools in 12/14/16/18/20 gauge, but you may have to use what you have.

A T/C should be wired with T/C extension wire and there is a color coded polarity to watch.

http://reotemp.com/thermocoupleinfo/thermocouple-color-codes.htm

I would recommend using the standards for 120V wiring from the line cord to the controller and the SSR to the outlet. Black / White / Green. Red is normally switched HOT.

Cu wire is Cu wire! Electrons flow thru a blue wire just as easy as a red one! [smilie=1:

banger

[SWAGE-X]

I always use different color for everything and never repeat the same color within the box or project, making tracing and hook-up a no-brainer.

I would recommend using the standards for 120V wiring from the line cord to the controller and the SSR to the outlet. Black / White / Green. Red is normally switched H

banger[/QUOTE]

Banger
Thank You

That is the game plan for mine.
Thnx Lots
Bob

[edctexas]

Color is only important to help the next person that is looking at it try to understand it. The other guys told you how the AC or power wiring color code is. Generally I try to use white wire with stripes for the low voltage wiring (from the TA-4 PID unit to the relay). The thermocouple needs to use thermocouple wire. Many of the TC's have too long a wire so you can shorten the part going from the TC to the outside of the box. I use a TC connector on the box holding the PID. The wire I clipped off is used from the inside of the connector to the PID unit. Using wire other than TC wire, give you small varying errors in what your trying to measure. If it was an offset you could stand that, but a varying number just adds confusion. Again if you have any questions, email me or PM me.

Ed C

[Retumbo]

Just a side note, you should use TC specific terminals if you go that route. I always either wire direct or go for the appropriate thermocouple plugs.

[bangerjim]

A little more info on "Industrial instrumentation 101"!

Those "terminals" or "plugs" are actually called isothermic connectors & are made of specific materials like the two different wires the T/c are made from. They eliminate, for the most part, any error in MV that occurs when you join two dis-similar metals (a T/C). Good industrial grade ones are $20-30 each.

In my industry, a 1 degree variance due to connections is critical. For simply heating a teeny little lead pot, not so important. A 5-8 degree error will not even be noticed.

But if one wants to be totally anal on temp control on a lead pot, buy and use the T/C matched isothermic plug and socket assembly, watch the polarity closely, and see tighter temp readings.

Anytime you have 2 dis-similar metals come together (screw terminals, spade lugs, connectors, solder joints, wire nuts) anywhere in the wiring, you create another T/C junction and it can either add to or subtract from the actual MV signal from the T/C junction at the tip based on the ambient temp.

The above, along with much improved accuracies, are the reasons industry uses 100 or 1000 ohm platinum RTD's for a vast majority of temp measurements below 1,000F. No compensation needed......just 3 standard wires!

[popper]

Drawing looks good but it is a SSR, not relay. If temp reads 70F then 98F when you hold probe, it's right. Assuming your connected to SSR terminals, try reversing them - that part of the SSR is an LED which won't light if connected backwards.

[Retumbo]

The plugs can be had on Digi-key for $3-4.

Daddy always said; "if its worth doing, its worth doing right"


A little more info on "Industrial instrumentation 101"!

Those "terminals" or "plugs" are actually called isothermic connectors & are made of specific materials like the two different wires the T/c are made from. They eliminate, for the most part, any error in MV that occurs when you join two dis-similar metals (a T/C). Good industrial grade ones are $20-30 each.

In my industry, a 1 degree variance due to connections is critical. For simply heating a teeny little lead pot, not so important. A 5-8 degree error will not even be noticed.

But if one wants to be totally anal on temp control on a lead pot, buy and use the T/C matched isothermic plug and socket assembly, watch the polarity closely, and see tighter temp readings.

Anytime you have 2 dis-similar metals come together (screw terminals, spade lugs, connectors, solder joints, wire nuts) anywhere in the wiring, you create another T/C junction and it can either add to or subtract from the actual MV signal from the T/C junction at the tip based on the ambient temp.

The above, along with much improved accuracies, are the reasons industry uses 100 or 1000 ohm platinum RTD's for a vast majority of temp measurements below 1,000F. No compensation needed......just 3 standard wires!