NFPA72 - 6.16.7 Door Unlocking Devices

[Leo]

NFPA72 2007 6.16.7 Door Unlocking Devices.

6.16.7.1 Any device or system intended to actuate the locking or unlocking of exits shall be connected to the fire alarm system serving the protected premises.

6.16.7.2 All exits connected in accordance with 6.16.7.1 shall unlock upon receipt of any fire alarm signal by means of the fire alarm system serving the protected premises.
Exception: Where otherwise required or permitted by the authority having jurisdiction or other codes.

6.16.7.3* For all exits connected in accordance with 6.16.7.1 and where batteries are used in accordance with 4.4.1.5.1(1) as the secondary power supply, the batteries shall not be utilized to maintain these doors in the locked condition unless the fire alarm control unit is arranged with circuitry and sufficient secondary power to ensure the exits will unlock within 10 minutes of loss of primary power. (( do not use Fire Power to keep doors lock ))

6.16.7.4 Locks powered by independent power supplies dedicated to lock power and access control functions and which unlock upon loss of power shall not be required to comply with 6.16.7.3.

6.16.7.5 If exit doors are unlocked by the fire alarm system, the unlocking function shall occur prior to or concurrent with activation of any public-mode notification appliances in the area(s) served by the normally locked exits.

6.16.7.6 All doors that are required to be unlocked by the fire alarm system in accordance with 6.16.7.1 through 6.16.7.5 shall remain unlocked until the fire alarm condition is manually reset.

A.6.16.7.3 A problem could exist when batteries are used as a secondary power source if a fire alarm control unit having 24 hours of standby operating power were to lose primary power and be operated for more than 24 hours from the secondary power source (batteries). It is possible that sufficient voltage would be available to keep the doors locked but not enough voltage would be available to operate the fire alarm control unit to release the locks.