WBF154H29(Power Supply 24V Frequency Sensor) uses a special isolation module to measure the AC power in the grid and circuit in real time, and convert it to DC current (Iz) output of 4mA ~ 20mA or 0mA ~ 20mA standard. Power Supply 24V Frequency Sensor adopts the card-mounted structure, terminal wiring, easy installation, using power supply 24V or 12V dc, and three isolations among input, output and power supply.