AlarmGard™ Chain Or Crank
For use on fire doors, insulated fire doors and counter fire doors. Automatically closes fire doors during building alarm, smoke detector activation or power failure. Rate of descent will not exceed 12" per second. External releasing devices are not required, eliminating costly wiring. Can be retrofit to most manufacturers' existing fire doors.
Can use 120 Volt AC, 24 Volt AC or 24 Volt DC Power from an external source or central alarm system. Optional battery backup can hold the door in the open position for up to 8 hours, preventing unwanted drops due to temporary power outages. It can also be used to power local detectors.