Motor operated fire damper

摘要

A fire and smoke damper having an electric motor coupled with the damper to hold the damper blades open when the motor is energized. A spring associated with the motor provides torque for closing the blades when the supply of electrical energy to the motor is interrupted. A thermal responsive electrical switch is mounted on the damper and incorporated in the electric circuit which supplies energy to the motor so that the motor is de-energized and the damper is closed when the ambient temperature reaches a predetermined level.