Lennox 67K30 SPST Pressure Switch 0.55" WC

The Lennox 67K30 SPST Pressure Switch is a essential accessory for most HVAC systems. It operates like an SPST, that is, the circuit possesses only one set of contacts to make or break on an input pressure. It is installed at a specific duct or chamber of the HVAC system that is to be controlled. If the pressure rises or falls within that area, a diaphragm in the switch responds. At this pressure of 0.55” WC, the diaphragm changes the position of the switch to make or break the circuit. This change in switch state can then be used to control various system functions.