FPA38 is monitoring the power consumption on 3-phase symmetrical load, primary motors.
The wanted metering range is selected by means of DIP-switches, from 0-3,46 kW up to 0-41,6 kW at 3x400 VAC supply, proportional to 0-20/4-20 mA on the metering output. 0-10 V is also possible, see below.
The supply voltage, 24 VDC, and the 3 voltage phases are connected to the relevant terminals. The current is monitored by putting the current phase L1 through the built-in current transformer, see connection diagram.