PR44-48 Wiring help

Can anyone offer a little assistance to make sure I wire a pressure transducer to the PR55-48 correctly. Wiring diagram for the transducer and the PR55-48 with M12 connector are shown below. I think the Grey, 16V supply should be connected to the + terminal of the transducer, but I’m not sure about the - terminal of the transducer… just connected to Black, ground? @Bhaskar

M12 Connection —

Blue — 4-20mA +Ve

White — External Power Supply +ve

Brown — 4-20mA -Ve

Black — Ground

Gray — 16V Supply ( To power External Sensor)

M12 Connection (PR55-5)

1 — 4-20mA -Ve

2 — External Power Supply +ve

3 — 4-20mA +Ve

4– Ground

5 — 16V Supply ( To power External Sensor)

M12 Connection (PR55-48)

1 — External Power Supply -ve Input

2 — External Power Supply +ve Input

3 — 4-20mA +Ve

4 — Ground

5 — 16V Supply ( To power External Sensor)

Hi,
You don’t need the power supply. PR55-48 will provide power.
The wires you will use are Blue and black.

Thanks

1 Like

Great, thanks for your help again!

@Bhaskar, I wanted to revisit this question. I wired the gauge with just the Blue and Black wires, and get a reading of 7.2mA with no change in current as pressure goes up or down. In the wiring diagram provided by the pressure gauge, it does say that 10-35V is necessary to supply for the correct operation. Can I use the Gray (5), 16V Supply to power the gauge? I’m not sure how I would wire the M12 connection in that case. Gray to + on the gauge, and then…?

No, the gray wire will not work if your sensor is two wire sensor.
Did you try swapping blue and black wire while connecting to the pressure sensor?

I did try swapping Blue for Brown, and the reading was 0.5mA, but again didn’t change with voltage. Swapping the polarity with Blue/Black didn’t change the reading.

The specs on PR55-48 say that 16V is available to power external 4-20mA devices. Why would it not work?

can you take the lid off the unit and share a picture

This is the Gauge (https://dwyer-inst.com/series-605-magnehelicr-differential-pressure-indicating-transmitter.html)

Here are pics of the back of the gauge and inside the PR55-48


i don’t see any issues with ncd hardware.
Does the pressure sensor have any boot time?

You can connect a meter between blue nad black, and you will see it produces 16V while its sampling the data.

OK, just tried that, and yes the voltage is 16v while sampling.

What about the pressure sensor boot time?

I don’t see any documentation on the gauge regarding boot time. This is a new gauge, and is supposed to be factory calibrated so zero pressure is 4mA. I’m not sure why when pressure is applied the device isn’t picking it up.

let’s do this

  1. connect your pressure sensor to a 12V supply nad connect a multimeter in series
  2. see what mA meter reads?

OK, I had to try a different multimeter, but with a 12V bench top supply putting 12V or 16V to the + connection, and a multimeter in series with the - connection, the meter is reading about 4.25mA and when I apply pressure it predictably goes up to ~20mA.

With the NCD device connected to + with the BLUE wire, and the multimeter in series with the - and BLACK wire, during a sampling I am reading two spikes, one around 6mA and then another briefly after that gets max’s at 8.83mA. But neither mA spike seems to change with pressure applied.

i am suspecting the boot time is the issue.
Do you have a gateway or modem?

Yes, a Edge Computer and the Ethernet Modem.

For future ref. Sensor boot time was increased to 5sec.
The default boot time is 1sec.