§ 7.59. Safety equipment.
(a) Slack cable device. A slack cable device shall be used in connection with all passenger elevators of the winding drum type, which will automatically shut off the power, apply the brake, and stop the machinery, in case the car is obstructed in its descent. The device shall be so designed and installed that, after functioning, the mere resetting of the device shall not be sufficient to move the elevator car unless the operator is in the car and starts it in the regular manner.
(b) Limit switches and terminal stops. Normal terminal stopping devices for electric traction elevators may be located on the car or in the hatchway or in the machine room and shall be operated by the movement of the car. Electric passenger elevators shall be provided with top and bottom final limit switches so connected that the functioning of either switch will automatically shut off the power, apply the brake, and prevent the operation of the elevator in either direction until necessary adjustments are made to again place the elevator in operation. Such switches shall be in addition to directional switches. Limit switches may be located in the shaftway with a cam on the car or on the car with cams in the shaftway. When necessary because of flood conditions, lower shaftway limit switches may be actuated by the counterweight at the top of the shaftway. Cams actuating limit switches shall be composed of metal. Automatic terminal stops shall be provided on the machines of power-driven passenger elevators of the winding drum type, such devices to operate independently of the car-controlling mechanism.
(c) Brake. All passenger elevators, except hydraulic, shall be equipped with an effective magnet release brake which is automatically applied when the controlling mechanism of the car is in a stop position. The brake magnet shall be so installed that its action is not retarded by any motor field discharge or counter electro-motive force or by any single ground or accidental short circuit. When direct current elevator motors derive current from an alternating current power source through a nonrotating rectifying unit, means shall be provided to absorb a sufficient amount of energy regenerated by the motors under overhauling load conditions to prevent any elevator from attaining at any time, or under any conditions of load, more than 120% of the contract speed of the elevator. When a single rectifier is installed to supply power for a number of elevators, or elevators in conjunction with other electrical equipment in the building, separate means for absorbing the generated power shall be installed for each elevator and other equipment in the building shall not be depended upon for the absorption of this power.
(d) Car safeties. Passenger elevators shall be provided with car safeties as follows:
(1) All passenger elevator cars suspended from cables shall be provided with safeties, located under the car floors. Such safeties shall be capable of stopping or holding the elevator car at any point of its travel.
(2) Passenger elevators having a speed of 100 or less feet per minute shall be provided with car safeties actuated by a centrifugal speed governor, except when the car travel does not exceed 20 feet, in which case car safeties of the spring grip or broken rope type may be used.
(3) When the speed is in excess of 100 feet per minute, regardless of car travel, the car shall be provided with car safeties of the friction clamp or other approved type, actuated by a centrifugal speed governor in such a manner as to bring the elevator car to a gradual stop within a distance of approximately eight feet.
(4) A rack and pawl is not acceptable as a car safety device.
(5) Governor cables shall be iron or steel, monel metal, phosphor bronze or equivalent and shall be not less than 3/8 inch in diameter. Tiller rope construction shall not be used for governor cables except that it may be used for the portion of the cable wound on the safety drum.
(6) The size, material, and construction of the governor rope, and the proper tripping speed of the governor, shall be stamped on the governor stand or on a brass plate attached to it in letters not less than 1/4 inch in height.
(7) Friction-type governors without cable clamp dogs may not be used.
(e) Counterweights. When counterweights in an existing installation operate in the elevator shaftway they shall be guarded in accordance with the requirements for new installations. When counterweights do not operate in an elevator shaftway they shall be entirely enclosed on all sides.
(f) Shaftway doors. Shaftway doors providing entrance to air cushions shall be of the gravity type, with inside latches; and, at the lower terminal landings, shall be provided with emergency exits. The plates of such emergency exits shall be thoroughly braced.
Source The provisions of this § 7.59 amended July 22, 1971, 1 Pa.B. 1651.
Cross References This section cited in 34 Pa. Code § 7.71 (relating to conflicts).
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