Lennox 88K90 0.47" WC SPST Pressure Switch

The Lennox 88K90 SPST Pressure Switch is a protective device which is incorporated in HVAC for the purpose of controlling air pressure. It is a single pole single throw switch which implies that it operated between one input and one output with a switch applying or removing a circuit based on the pressure limit. In furnaces and air handlers of the HVAC equipment the pressure switch plays a role of checking the pressure of the air inside the equipment to ensure safe and economic operation is observed. When air pressure gets to a certain level 0.47" Water Column in this case the switch is activated to switching on the fan or switching of the furnace so as not to let high pressure cause damage.