Temp Sensor

[agross]

I've got a 100k ohm duct sensor I'd like to install on a unit to get a DAT, we have SBT controls, and I think a standard sensor for that system is 1k ohm. Is there anything I can do to make my sensor work, or do I have to get a 1k ohm?

[ynut204]

Depends on what type of controller from SBT you are talking about. TEC can accept a 100K sensor, and 10K. MBC can take it too if you have a 100K module.

[agross]

Today I pulled all the wire and installed the sensor, I found an unused AI in my MEC and landed the wires there. I created a new LAI point, then I selected Thermistor 100 KOhm from the menu and calculated slope/intercept. When I ran a point log on the point, I got an outrageous value... over 10,000F and it had *F*. I changed it to just about every sensor there was, and it kept telling me the point was Failed.... Why? Does this mean there is a break in my wiring, did I wire it wrong in the MEC, I'm really confused now... Tomorrow I'm going to put a meter on it and check it out, does anyone else have any ideas??? Thanks.

[moe-air]

Don't know much about MEC, but ALC has bird jumpers on the inputs for 4-20ma, 0-5vdc, and thermistor/dry contact. Jumper needs to set in right position. Is there a needed gain value on your thermistors? Just a thought.

[ynut204]

The standard MEC doesn't take 100K ohm sensors. Even if you can calculate a slope and intercept for it, it won't give a good reading, regardless of jumper position.

[agross]

Well, I got my hands on a 1 KOhm and moved the jumper in the MEC and everything worked great. Thanks for your help!