Xylem-McDonnell & Miller 157S-MD Low Water Cut-Off W/Snap-Action Switch Max Differential 173603

The Xylem-McDonnell & Miller 157S-MD Max Dif W/Lwco/Snap Sw 173603 is a differential pressure switch intended for use in HVAC systems. It is necessary to protect equipment from damage and maintain the optimum possible airflow. An air handler's air pressure differential between the supply and return sides can be used to monitor problems such as clogged filters or broken fans. The switch initiates an automatic shut-off to guard against overpressure and possible system damage if the pressure differential rises above a safe threshold. It has a low water cut-off (LWCO) mechanism that, if the water level lowers, shuts down the system to protect boilers and other water-based components. This dual purpose makes it an invaluable tool for maintaining the longevity, effectiveness, and safety of different HVAC systems.