§1604.23. Terminal Stopping Devices.

(a) General Requirements.

Normal- and final-terminal stopping device switches shall conform to the following requirements:

(1) Where located on the car or on the hoist structure, normal- and final-terminal stopping device switches shall be of the enclosed type and securely mounted in such a manner that the movement of the switch lever or roller to open the contacts shall be as nearly as possible in a direction at right angles to a vertical plane through the face of the car guide members.

(2) Operating cams shall be of metal and shall be rigid.

(3) The switch contacts shall be directly opened mechanically.

Arrangements which depend on a spring or gravity, or both, to open the contacts shall not be used.

(b) Normal-Terminal Stopping Devices.

(1) Where Stopping Devices are Required and Function.

Upper and lower normal-terminal stopping devices shall be provided to stop the car automatically, at or near the top and bottom terminal landings, with any load up to and including rated load in the car and from any speed attained normal stopping means and of the final-terminal stopping device. The device shall be so designed and installed that it will continue to function until the final-terminal stopping device operates. The normal-terminal stopping device may be used as the normal stopping means.

(2) Location of Stopping Switches.

Stopping switches for normal-terminal stopping devices shall be located as follows:

(A) Stopping switches for traction machines shall be located on the car, on the hoist structure, or in the machine room, and shall be operated by the movement of the car.

(B) Stopping switches for winding-drum machines shall be located on the car or on the hoist structure and shall be operated by the movement of the car.

(C) Rack and pinion hoists shall have normal-terminal stopping switches located on the cage and operated by cams attached to the hoist structure or switches located on the hoist structure and operated by cams attached to the car.

(3) Requirements for Stopping Switches in Machine Rooms.

Stopping switches located in a machine room shall conform to the following requirements:

(A) The stopping-switch contacts shall be mounted on, and operated by, a stopping device mechanically connected to, and driven by, the car. Stopping devices depending on friction or traction shall not be used.

(B) Tapes, chains, ropes, or similar devices mechanically connecting the stopping device to the car and used as a driving means shall be provided with a device which will cause the electric power to be removed from the elevator driving-machine motor and brake if the driving means fails.

(C) Only one set of floor-stopping contacts is necessary for each terminal landing on floor controllers or other similar devices used to stop the car automatically at the landings (such as automatic operation, signal operation, etc.), provided these contacts and the means for operating them conform to the requirements of Sections 1604.23(b)(3)(A) and 1604.23(b)(3)(B). These contacts may then serve also normal-terminal stopping devices.

(c) Final-Terminal Stopping Devices.

(1) Where Stopping Devices Are Required and Function.

Final-terminal stopping devices shall be provided and arranged to cause the electric power to be removed automatically from the hoist driving-machine motor and brake after the car has passed a terminal landing. The device shall be set to function as close to the terminal landing as practicable but so that under normal operating conditions it will not function when the car is stopped by the normal-terminal stopping device. Where spring buffers are provided, the device shall function before the buffer is engaged. The device shall be so designed and installed that it will continue to function at the following:

(A) At the top terminal landing, until the car has traveled above this landing a distance equal to the counterweight runby plus 1 1/2 times the buffer stroke, but in no case less than 2 feet.

(B) At the bottom terminal landing, until the car rests on its fully compressed buffer.

The operation of final-terminal stopping devices shall prevent movement of the car by the normal operating devices in both directions of travel and shall be reset manually.

(2) Location.

Final-terminal stopping devices shall be located as follows:

(A) Hoists having traction machines shall have final-terminal stopping switches located on the hoist structure and operated by cams attached to the car.

(B) Hoists having winding-drum machines shall have final-terminal stopping switches located on, and operated by, the driving machine and also stopping switches located on the hoist structure and operated by cams attached to the car.

(C) Rack and pinion hoists shall have final-terminal stopping devices located on the cage and operated by cams attached to the hoist structure or switches located on the hoist structure and operated by cams attached to the car.

(3) Controller Switches Controlled by Final-Terminal Stopping Device.

The normal- and final-terminal stopping device shall not control the same controller switches unless two or more separate and independent switches are provided, two of which shall be closed to complete the driving-machine motor-and-brake circuit in either direction of travel. Where a two- or three-phase AC driving-machine motor is used, these switches shall be of the multi-pole type.

The control shall be so designed and installed that a single ground or short circuit may permit either, but not prevent both, the normal- or final-terminal stopping device circuits from stopping the car.

(4) Requirements for Drum-Type Personnel Hists.

Final-terminal stopping devices for drum machines shall conform to the following requirements:

(A) Stopping switches located on, and operated by, the driving machine shall not be driven by chains, ropes, or belts.

(d) Terminal Speed-Limiting Devices.

Terminal speed-limiting devices shall be installed when reduced-stroke oil buffers are used, and car speed exceeds 300 feet per minute. These devices shall conform to the following requirements:

(1) Terminal speed-limiting devices shall operate independently of the normal-terminal stopping device should this device fail to slow down the car at the terminal as intended.

(2) Terminal speed-limiting devices shall provide a retardation not in excess of 32.2 feet per second per second.

(3) Terminal speed-limiting devices shall not apply the car safety.

(4) Terminal speed-limiting devices shall be so designed and installed that a single short circuit caused by a combination of grounds or by other conditions shall not prevent their functioning.

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