Why are door restrictors necessary?
Elevator safety codes mandate the use of door restrictors as a safety measure. The primary rule is ASME A17.1, 111.5, which specifies the requirement for door restrictors: (a) When a car is outside the unlocking zone, the hoistway doors or car doors shall be so arranged that they cannot be opened more than 4 in. (102 mm) from inside the car. (b) When the car doors are so arranged that they cannot be opened when the car is outside the unlockiing zone, the car doors shall be openable from outside the car without the use of a special tool. (c) The doors shall be unlocked when the car within 3 in. (76 mm) above or below the landing and shall be permitted to be unlocked up to 18 in. (457 mm) above or below the landing. For elevators installed under the 1980 edition of ASME A17.1 and later, door restrictor guidelines are provided in ASME A17.1 1998b Rule 111.5/111.12 or ASME A17.1 2000 Item 2.12.5. The A17.1 Handbook Safety Code for Elevators and Escalators, 2000 Edition, Section 2.12.5, exp
