Powered damper having automatic static duct pressure relief

摘要

A damper (80) is provided for controlling the flow of conditioned air supplied through a supply duct to a conditioned space. The damper includes a support housing (95) which defines a flow passage which communicates the supply duct with the conditioned space. A plurality of damper blades (110) are mounted within the support housing (95) for pivotal movement about respective spaced apart parallel axes. A blade link (120) interconnects the damper blades (110) in a ganged relation so that a common pivoted orientation of the damper blades (110) is determined by the position of the blade link (120). Means are provided for selectively exerting a force on the blade link (120) which will move the link between first and second positions to respectively decrease or increase the flow of air through the damper (80). Means are provided which allows the blade link (120) to move toward the second position (maximum flow) in response to a force imparted on the damper blades (110) by a build-up of pressure in the supply duct. Under such circumstances the force imparted upon the damper blades is sufficient to overcome the force exerted on the blade link to move the link toward the first position (flow substantially blocked).