D-9502 Pneumatic Damper Actuator Positioner D-3073
D-9502 Pneumatic Damper Actuator PositionerThe D-9502 Pneumatic Damper Actuator Positioners are precision relay devices used to adjust and maintain damper actuators in exact positions on those applications requiring precise or otherwise special damper positioning.The basic positioner provides dynamic stabilization and/or sequential control of damper actuators. It is available factory installed on most D-3000 Series Damper Actuators.
Depending on the size of the actuator used, up to three additional actuators may be controlled by a single positioner/actuator assembly; for example, multiple actuators
modulating large or coupled dampers.
Feedback from the actuator shaft (through the positioner spring and lever arm assembly) activates the positioner to compensate for external forces at the shaft and holds the actuator at the position dictated by the controller. Supply air enters the control chamber of the relay and is admitted to the actuator when the control pressure in the pilot chamber exceeds the established starting point. This pressure causes the actuator shaft to move. Movement of the shaft is fed back to the relay through the positioner spring and lever arm to impose a balancing force against the control pressure. When all forces are in balance, the positioner will not allow supply air to pass through to the actuator. The actuator will establish a position proportional to the value of the pressure from the controller. Any change in shaft position will inbalance the relay, causing air pressure in the actuator to increase or be exhausted to reestablish a balance at the desired shaft position.
Replaces Part Numbers: D-9502-12