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this post was submitted on 19 Feb 2024
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Usually, if a building has electronic access control, it's a requirement that the main controller or power supply be directly tied into the fire alarm with a hardwired trigger relay to drop power to all the door locks during an alarm. It may all be controllable and configurable on the cloud, but commercial equipment still has traditional redundancies like standby batteries and the like.
What if there's a gas explosion or another case that causes loss of connection between the system and the doors? Is it possible to open them manually in such cases?
If the door has no means of mechanical egress, for example, a maglock, then it is required to have a second form of egress that cuts power to the maglock, such as a normally-closed exit button. Maglocks naturally unlock when losing power. Electric strikes and locksets can be set up fail-safe or fail-secure.
Not the commenter you replied to, but these kinds of systems are usually "fail open": if there is unexpected loss of power (including the locking mechanism connection to the controller being interrupted), the door is released/unlocked, and can be opened manually by users.
Some more complex systems will have specific doors automatically shut in the event of a fire to try and keep it contained, depending on local regulations. These doors can still be manually re-opened, but they will not "catch" or latch open until the system fault is resolved
Edit: add clarity