Voltage and Current monitoring on 750VDC

Hi, I’m looking to make a data-logger to log voltage and current from a 750V DC source. I already have a current transducer and a voltage transducer fitted in a system, but want to piggy back off these by connecting them to an arduino to log the data to an SD card/USB drive.

The Voltage transducer (LEM DVC1000) is a 4 wire sensor and provides a 4-20mA current signal out of the secondary side. I have found various posts regarding 4-20mA current loop sensors.

The current transducer (LEM ITC2000) looks like it provides a 0-1.2A signal out of its electronic interface.

I also will be looking to tag RTC/GPS to each sample. I have a good idea on what to do for this.

Could anyone guide me on this? Best ways to wire the signals to the arduino. I have an arduino uno R4 WiFi.

Welcome!

I do not recommend you connect a resistor in series with the 4-20 loop and measure the voltage drop.

The best would be to use a hall effect current sensor. Using the Hall effect sensor can measure DC current by detecting the magnetic field generated by the current flowing through a conductor. This allows for a safer contactless measurement of the current without interrupting the circuit.

It appears you have a voltage sensor that is also 4-20mA so a second hall sensor would do it.

This may help: https://www.youtube.com/watch?v=B2I6vgl-SJw

Both transducers use current as the signal. Connect a resistor between an analog input and ground.

For a 5 volt logic Arduino use the value of 5 / 0.020 for the current loop device and 5 /1.2 for the current transducer. Regard the heat of 6 Watt from the current resistor.

For 3.3 volt levels change 5 to 3.3. 4 Watt of heat.

Do you have a schematic of how they are connected now?

Unless you know how they are currently connected, you risk upsetting their correct operation by making additional 'piggy back' connections.

The sensor is not a 4-20mA current loop sensor.

The output is a current that goes up to 20mA (for 1000V full scale), but the sensor is bi-directional. If you apply the voltage in the reverse direction the current goes to -20mA.

It will require building some custom electronics and possibly cutting the wires of the current installation.

I don't recommend doing it.