Trane CNT3814 Dual Pressure Switch

The Trane CNT3814 Dual Pressure Switch is used to measure and regulate the air pressure in a number of HVAC equipment. It has two different switches, one that is designed to turn on at 0.14” WC pressure and one that turns on at 0.18” WC pressure. The air pressure that gets to a certain level of set point switches on or off an electrical circuit. Some of the fan dampers and other parts of the HVAC system are regulated by this electrical reaction to maintain the pressure and flow rate of the system. The switch will turn on the fan and therefore increase airflow if the pressure becomes too low.