APN Series power-monitoring sensor measures three phases of current and voltage, and computes 14 values to track power use in the RS485 Modbus RTU format. To measure watts in an ac circuit, the supplied voltage is compared with the current and indicates whether the current peaks before the voltage (leading power factor in a mostly reactive circuit) or the current peaks after the voltage (lagging power factor in a more inductive circuit). It can be configured to accept standard 5-A current transformer inputs or sensors producing 333 mVac proportional to the ac current of the circuit.
