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Subchapter 6. Elevator Safety Orders
Group 3. New Elevator Installations, Article 37. Seismic Requirements for Elevators, Escalators and Moving Walks

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§3137. Seismic Requirements for Elevators, Escalators and Moving Walks.

Elevators shall comply with the seismic requirements for elevators in Part XXIV of ASME A17.1-1996, except for Rule 2409.1b(1), which is hereby incorporated by reference.

(a) Earthquake protective devices shall be designed, arranged, and maintained to ensure that if any component fails, the elevator will go into the earthquake-sensed mode and be removed from service in the same manner as though an earthquake were occurring, and that the elevator will so remain until the faulty component has been repaired and the system is again arranged to work as intended.

(b) For hospital buildings, the earthquake sensing device shall activate upon excitation in a horizontal or vertical direction of not more than 0.5 g.

(c) Earthquake protection devices shall be arranged to be checked once a year for satisfactory operation and shall be calibrated at intervals recommended by the manufacturer.

(d) The following requirements apply to escalators and moving walks and are in addition to the requirements contained in other parts of this code:

(1) Connections which join the escalator or moving walk to the building shall be designed for seismic loads of 0.5g in both principal horizontal directions.

(2) The design connections shall provide for maximum design story drift.

(A) Seismic restraint shall be provided. Where seismic restraint is provided at one end, the design shall account for torsion. All other supports shall be free to slide in the longitudinal direction. Where seismic restraint is provided at both ends which allows some degree of longitudinal and transverse motion, additional means shall be provided to prevent the upper ends of the truss from slipping off the building support. All other supports shall be free to slide sufficiently in the longitudinal direction to accommodate the remainder of the design story drift.

(B) At the sliding end or ends, the width or widths of the beam seat shall be capable of accommodating, without damage, at least two times the current code allowable story drift (see Title 24, Chapter 16A, Section 1628A.8) in both tensile and compressive modes.

(C) Seismic restraint shall be provided in the transverse direction at all supports. Intermediate supports, if any, shall be free to move laterally in all directions. The gap between the escalator truss and the seismic restraint shall not exceed 1/4 inch on each side.

(3) The handrail supports shall be designed to resist a lateral load of 50 lb/ft applied at the top of the handrail. In balustrades which contain glass, the glass shall not be part of the structural support system of the handrail unless documentation can be presented, to the Division, to verify the glass used in support can withstand the stresses occurring during an earthquake.

(4) A minimum of one seismic switch shall be provided in every building in which an escalator or moving walk is installed.

(A) The seismic switch shall activate according to manufacturer specifications at a level and direction established by the escalator/moving walk manufacturer and a California registered professional engineer.

(B) Activation of the seismic switch shall remove power from the escalator or moving walk and apply the brake.

(C) Where a seismic switch is used exclusively to control the escalator or moving walk, it shall be located in an escalator or moving walk machine room and where possible shall be mounted adjacent to a vertical load-bearing structural member.

Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.


1. New article 37 (section 3137) and section filed 9-25-98; operative 10-25-98 (Register 98, No. 39).

2. Amendment of article heading, subsections (d)(2)(C) and (d)(4)(C) and Note filed 4-1-2008; operative 5-1-2008 (Register 2008, No. 14).

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