What must any device intended to lock or unlock exits be connected to?

Devices intended to lock or unlock exits must be connected to the fire alarm system to ensure safety during emergencies. NFPA 72 emphasizes the importance of maintaining safe egress during a fire or other emergency situations. When these locking devices are linked to the fire alarm system, they can automatically unlock when an alarm is activated, allowing for unimpeded exit from the building. This connection is vital in maintaining compliance with life safety codes, which prioritize the safety and quick evacuation of occupants in the event of fire or danger.

In contrast, while building power supply, local law enforcement, or manual override systems could provide functionality, they do not serve the same critical purpose in ensuring automatic compliance and swift evacuation in emergencies as a direct connection to the fire alarm system. Therefore, connecting exit locking devices to the fire alarm system directly supports the goal of preserving life safety during emergencies.