Rolling fire door including a door hold-open/release system

摘要

A rolling fire door includes a door hold-open/release system that includes an electromagnet which is energized by a controller when the door is in the open position. The energized electromagnet magnetically attracts a bottom bar of the rolling door to secure the door in the open position. A key control station connected to the controller enables the electromagnet to be energized when the door is in the open position and enables the controller to deenergize the electromagnet so that the weight of the door causes the door to close. The key control station also includes a test switch which enables the controller to deenergize the electromagnet after a delay interval. The controller also deenergizes the electromagnet after a delay interval in response to activation of an alarm or in response to a thermal switch sensing a temperature in excess of a set point temperature.