Car Safeties And Governors

(1) Elevator cars shall be provided with a car safety capable of stopping and sustaining the car with rated load. (2) The car safety shall be of the inertia or other approved type operated as a result of the breakage of the hoisting mechanism or by a speed governor. If of the speed-governor type, the governor shall operate to set the safety at a maximum speed of 75 feet per minute and on breakage of the suspension means, the safety shall operate without appreciable delay and independently of the governor speed action. (3) Where a speed governor is used, it shall be located where it cannot be struck by the car or the counterweight in case of over travel and where there is sufficient space for full movement of the governor parts. (4) A safety operated switch shall be provided to open the motor-control circuit and the brake-control circuit before or at the time the safety applies. (5) The governor ropes shall be of iron, steel, monel metal or phosphor bronze not less than ¼ inch in diameter. Tiller-rope construction shall not be used for governor ropes. (6) Elevators of the winding-drum type or roller chain drive type shall be provided with a slack-rope device of the manually reset type which will remove the power from the motor and brake if the car is obstructed in its descent and hoisting chains or ropes slacken. (7) A car safety device which depends upon the completion or maintenance of an electric circuit for the application of the safety shall not be used. Car safeties shall be applied mechanically. (8) Cast iron shall not be used in the construction of any part of a car safety, the breakage of which would result in failure of the safety to function to stop and sustain the car. (9) A test of the car safety shall be made with rated load in the car before the elevator is put into service. Governor operation of instantaneous-type safeties shall be tested at rated speed by tripping the governor by hand. Safeties operated as the result of the breaking of the hoisting mechanism shall be tested by obtaining the necessary slack-rope to cause them to function. (10) Where a traction machine is provided, an overspeed governor shall be required.