Engineering notes
Standby power for emergency-exit doors and access control
Magnetic locks, break-glass, standby power on escape doors. Fail-safe on power loss.
An escape door must open when power fails
A magnetic lock holds the door while powered. On power loss the door must open if it is an escape route. Standby power and the fire-alarm cut must follow the fire file. Do not buy a handsome access kit and land it fail-secure by default.
Fail-safe: power loss unlocks (magnet drops) — correct on an escape door. Fail-secure: power loss stays locked — stores, not escape stairs. One door, two circuits: access and emergency release. ELV