3 wire 0-20mA sensor input on MC4x

Kevin Arscott 3 years ago in Master modules / MC4x updated by Gustav Widén (System support) 4 months ago 6

The installation manual states an example for a 2 wire 0-20mA input into the controller, but there is no reference to a 3 wire input. Are these supported? I'm assuming it will be the same connections just the sensor ground (which does not include the signal) will go to chassis or vref -ve? Can anyone confirm?

Can anyone advise whether it is possible to connect 3 wire to MC4x controllers please?


Most of the current sensors have 3 wires

Just connect the power to the + and gnd connection and the signal wire to the iqan input

You do not need the vref- because the sensor normally has a controlled current output

Used it with pressure sensors.....works fine

Good morning, sorry, but as this post was marked as Answered, I am not sure if my Replay is seen by someone.

So, I try answering you directly.

Not sure how this forum works at all...

Hello, can someone confirm that the 3 wire sensors can really connect to GND as was said in this post?

Because according the manual: "NOTICE
The negative terminal of the sensor must not be connected to the chassis."

We  would like to use the CIN inputs of the XC4x, but our pressure transducers are 3 wire sensors.

Can we connect the negative to -VREF instead ground? Or that doesn't work either?

Thanks in advance!


You could connect the sensor ground either to the module ground or to the -VREF pin on the module.