SLC5/03 NIO4V Question

I have a AB 5/03 and would like to use a 1749-NIO4V card to control some SSR's to power heating elements. I currently have thermocouples hooked up to Auber PID's. I know I cannot use thermocouples with the card usless I use a tempeture transmitter.

My question is would it be possible to use a thermistor and how accuratly would I be able to scale? Im looking to hold a set tempeture at 170F and 150-155F.

You need to investigate very closely the fact that ssr's have one phase hot all the time and that you might have voltage feedback through the backplane which will cause you problems. A co-worker had problems in the past, but i didn't know how he wired the system.

i had ssr's on a 100 kw heater that kept blowing and eventually replaced the controller with a mercyry contactor and temp controller.

regards,
james

Maxkling said:

I have a AB 5/03 and would like to use a 1749-NIO4V card to control some SSR's to power heating elements. I currently have thermocouples hooked up to Auber PID's. I know I cannot use thermocouples with the card usless I use a tempeture transmitter.

My question is would it be possible to use a thermistor and how accuratly would I be able to scale? Im looking to hold a set tempeture at 170F and 150-155F.

Click to expand...

You can't connect a thermistor to that card without a transmitter either. And expect an accurate reading.

Mickey,
thanks for pointing that out.

ab also makes an 8 input rtd card for thermistors.

regards,
james

James Mcquade said:

Mickey,
thanks for pointing that out.

ab also makes an 8 input rtd card for thermistors.

regards,
james

Click to expand...

RTD card, yes. But I'm not aware of a card for a thermistor.

Do you have a catalog number?

Yes, I know about the thermocouple compatible card, but it is out of my price range for personal use. Thus, is why I'm looking for a way to make what I have work. This is a whole new learning curve as I've never temperature controlled with a PLC before. Ive only used the stand alone PID's and was just looking to learn more with using my rack instead of the PID's.

Has anyone used a tempeture transmitter to use the mV scale of the thermocouple to output a 10V scale for the analog card?

What you're looking for there would be called a Signal Conditioner. As far as I'm concerned, Action Instruments is the best in the business for that kind of product...

Something like this would work quite well for you.

Here is a couple more brands. There are many others.


http://www.miinet.com/products/sg_temperature.shtml

http://www.automationdirect.com/adc/Shopping/Catalog/Process_Controls/Signal_Conditioners