Global Processing

Bypass Damper Switch is Designed to Control Motorized Dampers

May 18, 2010
The bypass damper switch is designed for use with a three-wire floating-point damper actuator used to control the static pressure on zone control systems requiring motorized bypass dampers. A bypass damper bypasses air from the discharge air side of the HVAC unit back in the return air side. The air flow is modulated in order to maintain a constant static pressure in the system as individual zone dampers open and close. The unit’s static pressure control is equipped with solid-state switching which dramatically increases the life of the control. On an increase in static pressure the switch will send 24 volts out to the actuator to drive it open. When the static pressure reaches set point the actuator will stop. After a ten second delay the actuator will start to drive the damper closed if there has not been an increase in static pressure. A green LED indicates when the damper is in the open position or being driven open. The installer has everything required for installation including tubing and two static pressure probes.