Trying to setup temprature sensors on a General Input Unit??

Good day

I am desperately trying to setup a few temprature probes on the Clipsal general input unit.

We have installed PT 100 thermistors at various points on our system. We need to switch pumps and solenoids at specified tempratures.

How is this possible, if so????

HELP PLEASE.

Thanks
Kind regards
Shaun

 

GI Temp sensors

Shaun, though a little more expensive you could try using 4-20mA active sensors, these are simple to set up and work very well !

 

PT100 temperature sensors are not going to work very well with a General Input Unit (GIU).

The PT100 has a resistance of 100 ohms at 0?C and 138.4 ohms at 100?C. The most suitable measurement range on the GIU is the 500ohm range. On this range, the resolution is about 2 ohms (500 ohms / 256 steps), which will give a temperature resolution of about 5 degrees. If this is good enough, then it just needs to be wired to the GIU in accordance with the instructions for measuring a resistance.

If this is not good enough, then you have two choices:
1. Use different sensors
2. Use some sort of pre-amplifier to give an output (voltage or current) more suited to the GIU

 

Me two

Hello All,

I am about to set up a GIM for measurment of temperature , I agree with this post PT100 is too small a change in resistance vrs its range for most device analouge input resolutions, cant see why they are so popular in PLCs.

I can get a thermistor in just about any range but would like to use one that has been done before, has any one configured a GIM for temperature via a Resistive input. And the set up they used.

I understand 4-20mA or 0-5VDc will be easier, linear etc but cost heaps more.

Ta MikeS