Automation Direct signal conditioner

[patm72]

I'm using an Automation Direct signal conditioner (FC-T1) and have trouble with it.

Actually, my thermocouple type K needs me to adjust the DIP switches as 0111 (switches in order 8-7-6-5). I'm following instructions for the wiring but I'm measuring no current from the output even though my thermocouple is connected and the module itself is not in fault (green LED solid). My thermocouple has its two leads jumped together so it should read ambient T.

Ideas anybody?

Thx

 

[buzzp]

The two leads jumped together statement, what exactly does this mean? Are you using a probe or what? I have used both and not sure if your statement is stating that the two leads are soldered together at the end of the thermocouple wire or at your device to read the temp. It is normal for thermocouple wire to be shorted together at the end of the wire where you want to know temp. You should NOT jump them together at the end where it plugs into your device, if you are, thats your problem, you are shorted out the small potential developed by the thermocouple so it sees zero volts which is probably out of range of your device so it shows no temp (assuming the current out you said you measured is some sort of 4-20mA signal from the device).

 

[patm72]

I am using no probe. I just joined together the two wire tips of the thermocouple extension wire. Where it plugs into the device, the two leads (green and white) are separated, as they should be.

 

[VEBill]

Is the 'extension' wire the same as 'thermocouple wire'?

 

[analogkid2digitalman]

Isn't convention for K type thermocouple leads to be Yellow (+) and Red (-)? Are you sure of the proper wire type?

When you say you joined the leads of the T/C extension wire together, did you use a single point spot weld?

For sanity, I would buy a pre-made T/C to test the module (Omega).

Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.

 

[buzzp]

I have joined the tips of thermo wire before. I did not like it because I never really had that much confidence in the results. However, I did verify the results with a known good temp reading and they were right on. It did take on or two tries to get just the right amount of solder on there (I actually dont think this is the ideal way to join thermo wire).

I would take Analogs advice and use a known good probe or already made up wire to test your module.

 

[fangas]

Hi Pat,

I would suggest you do the following,
1). Make sure the DIP switches are set exactly like the example.
2). Disconnect your homemade T/C and turn the conditioner on. It should immediately ramp up to around 20+ mA. This is the "upscale burnout" feature working.
3). Take a piece of real K type extension wire about a foot long and strip about 1/2in off. Clean the bare ends to get rid of anything left. With 2 pairs of pliers, twist the 2 ends together, TIGHTLY. You now have a K type T/C. Not an accurate one, but we don't care about accurate, we just want to see if it works.
4). Connect the other end to the conditioner and turn it on.
5). Put a cigarette lighter or some other source of heat to it. You want a higher temperature then ambient, 75F is way to far down the scale to miss with when using a K type T/C. It should start ramping up.
6). Take the heat away and observe. You should see the output go down as the T/C cools off.

If all that works as described, most likely nothing wrong with your conditioner. My guess is you're not using real T/C extension wire, because like A2D said, it's Red & Yellow insulation on K type wire.


Hope that helps some

Ed

 

[patm72]

Green/White combination of wire color is the European standard for type K. Yellow and Red is (as far as I know), North America.

I had joined the 2 leads together tightly as suggested.

Now, having connected it with an Automation Direct analog 4-20mA input card, it works.

Thank you all for your advices and suggestions.

 

[analogkid2digitalman]

Hot Stuff, Pretty Cool.

Glad to hear you are up and running!

Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.

 

[buzzp]

Not sure how that changed anything unless your solder joint was a cold solder joint.
Ahh, perhaps you really did have a jumper wire between the two wires of the thermo wire. That would explain it. If so, good catch fangas. (not sure why 2 pairs of pliers are needed to twist wire though).