To enable neutral current readings on your Shelly Pro 3EM, you must install an additional current transformer (CT) clamp dedicated to the neutral channel. This CT clamp should feature a 2-pin MX3.0-2x1Y connector.
Installation and Calibration Steps
Install the Neutral CT Clamp
Place the Neutral CT around one of the phase conductors (A, B, or C) - not around the neutral line itself.
Access Phase Calibration Settings
Open the device’s Settings menu. Best is to perform the calibration from the local web interface of the device.
Navigate to Phase Calibration.
Calibrate the Neutral CT
In the “From phase” field, select the phase where the Neutral CT is installed (A, B, or C).
Under Calibrate Phase, choose Phase N.
Click Calibrate to complete the process.
Move the Neutral CT to the neutral line.
Viewing Neutral Current Readings
After successful installation and calibration, neutral current measurements will be available through the device’s local web interface, app UI.
These readings are obtained via the local EM.GetStatus API method.