4-way signal conditioner, screw connection and a Rogowski coil with 600 mm long, 190 mm diameter to measure the AC current busbars and high voltage lines. On the output side, the signal conditioning amplifier 8 outputs different standard signals and an output switching, voltage supply 9 to 30 Vdc input and output set by DIP IP20, working temperature of -30 ° C to 80 ° C, Phoenix.