4-20mA Float switch wiring questions

[santisiah]

Hello,

I have a float switch that is labeled as below and has only 2 wires (red,black):

Input 10-30VDC
Output 4-20mA
Resolution 5mm

I am using an Analog/Digital card and need help wiring...

The card shows CH1: V+, I+
V-/I-, SLD

I'm assuming I use the 24VDC from my power supply but do I just hook that up to the red and then the black to the V-/I- and jump to I+? Do I need a resistor anywhere?

Thanks a lot

 

[Mickey]

I am using an Analog/Digital card and need help wiring...

Which is it analog or digital. Can you post the complete catalog number of your card. Can you also post the complete catalog number of your float ( switch?) or is it a level transmitter. A 4-20ma output would indicate a transmitter not a switch.

 

[santisiah]

It's actually an Analog input module.. Mitsubishi L60AD4 (I guess I called it analog/digital because of the AD).

The float is a transmitter, sorry I called it a switch, but it is a continuous float that is 4-20mA..

 

[cjd1965]

Hi wire the card like this picture.Note the V+ and I+ are linked.

I would assume the float is loop powered but check your manual.

If it is take the +24V from the card to the + of the sensor, and - of the card to the - of the sensor

 

[santisiah]

CJD,

I don't see where it says if it is loop powered or not. Here is the link to the float and the model is C3975. http://www.madisonco.com/continuous/float.php

Also, you said "If it is take the +24V from the card to the + of the sensor, and - of the card to the - of the sensor".. Does this mean my card is already supplying 24VDC?

Thanks

 

[Mickey]

I am not a Mitsubishi guy so hopefully those that are will jump in.

 

[cjd1965]

Hi
I haven't used that particular card.


Link out the V+ and I+ and see what volts you get between I+ and I-.

The manual says you MUST link it together for a current input.

Report back with your findings

 

[bernie_carlton]

Supplementing CJD1965's diagram

 

[cjd1965]

Nice one Bernie

 

[bernie_carlton]

From simple minds come simple diagrams.

 

[santisiah]

From simple minds come simple diagrams.

Bernie,

That's how I imagined it but didn't know if a resistor was required. I'll try it and see what happens..

Thank you guys

 

[bernie_carlton]

The 'required resistor' is the internal 250 ohm one shown in CJD1965's diagram