Landing Door Interlock: Dual Function Electrical Contact Mechanical Lock, 300N Resistance, Emergency Key, Unlocking Zone ±200mm and EN 81-50 Type Test

The landing door interlock (door lock, landing door lock, inter-locking device) combines two essential safety functions: (1) Electrical: a direct-opening safety contact in the safety circuit that breaks the circuit if any landing door is not fully closed and locked — preventing car movement with an open door; (2) Mechanical: a latch or hook bolt that locks the door panel and prevents it from being opened from the landing side when the car is not at that floor — preventing a person from falling into an empty hoistway. EN 81-20 Cl. 7.7.2 requirements: (a) Door must be locked before car moves — the electrical contact closes only after the lock bolt is fully engaged; (b) Mechanical locking strength: 300 N applied at door edge perpendicular to door plane; (c) Emergency opening from outside: special triangular or square emergency key (EN 81-20 defines the key profile); (d) Unlocking from outside requires two deliberate movements; (e) Fail-safe contact — loss of circuit tension opens the circuit; (f) Car must be within the unlocking zone (typically ±200 mm of landing sill) for the mechanical lock to be released from inside. Type-testing per EN 81-50; CE marked as a safety component. Interlock types: hook bolt (pivoting hook on door leaf engages fixed striker on frame); bi-parting door interlock (both panels must close for lock engagement); vertically sliding door interlock. Periodic inspection: verified by attempting to open the door from the landing with the car away from the floor.

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