The CU-ADP2/CU-ADP2.1/CU-ADP3 CU adapters permit the external operation of Landis+Gyr communication units (from 2nd generation onwards) together with meters in which no communication unit can be fitted. They generate the supply voltage for the built-in communication unit from the mains voltage. Voltage CU-ADP2 1-phase Rated Voltage Us 58 to 240 V AC DC Voltage Us 125 to 245 V DC Voltage Range 80 to 115% Us Voltage CU-ADP2.1 1-phase Rated Voltage Us 100 to 230 V AC DC Voltage Us 48 to 125 V DC Voltage Range 80 to 115% Us Voltage CU-ADP3 1-phase Rated Voltage Us N/A (DC only) V AC DC Voltage Us 24 V DC Voltage Range 80 to 115% Us Frequency Rated Frequency fs 50 or 60 Hz