Description
The York S1-02435270000 SPNO Air Pressure Switch is a safety switch meant to prevent HVAC systems from being exposed to low air pressure. It is an air pressure switch, SPNO type, it is normally open and it will close if the pressure is below a certain value. In this case, the pressure range is -0.45” WC inches of water column meaning that the switch will turn on when the system pressure is below this pressure range. This switch is used in different HVAC equipment such as air handlers, fan coil units, and rooftop units. When the pressure inside the system is below the -0.45” WC, the switch makes contact and sends a control signal.
