Short notes on Cable Elevators

If the building is of greater than six floors in height, it will have cable elevator. The lodging guest sees only one part of the entire system, the elevator car, which must be continuously cleaned by porters.

Car maintenance involves keeping the visible-control push-button system in perfect operating condition, the car lighting system in repair, hand-rails properly secured, and the telephone in operating order, alarms connected, and the public address system working within the car.

Every aspect of the car must be in perfect condition. Car doors must be checked at least once each day to ensure that they are working properly. Door rate of closure generally is set by local codes and must be checked and adjusted if they are closing too fast.

Maintenance personnel should be required to ride in the car each day to make sure it is moving smoothly and without noise or vibrations.

During this check, they should determine whether the acceleration and deceleration rates are correct. While checking for door closure speed, the door safety devices the traffic sentinel (electric eye) and the door safety edge must be checked each day.

These tests are simple. If there is an obstruction in the door when it is closing, will the door strike it and reopen? In addition to the car door operation, the floor shaft doors must be periodically checked and tested to ensure that their closure speed is synchronized with the car doors.

In addition, floor shaft doors should be checked every 6 to 12 months to ensure that they can be opened from the elevator car during an emergency. The car push-button controls for door open and door close must be checked because these override the main control system.

Even with a perfectly maintained elevator car and floor shaft doors, there will be passenger accidents. Most elevator accidents are caused by passengers and are not Mechanical system failures. The manager and his staff cannot eliminate these accidents.

Attached to the car are cables. Cables ride over the driving sheave, and their opposite end is attached to counterweights. Counterweights are used to offset the weight of a partially loaded elevator car. They reduce energy requirements to accelerate and decelerate the car.

Actually, the only energy requirement is to move the difference in weights between the counterweights and the car. Old counterweights are one component that can be used with modernized elevator systems; they do not have to be replaced.

Cable replacement is frequently one of the major cost items of periodic maintenance. Cables do not last forever. Cables stretch, which reduces their diameter; cables wear, which shows as fraying; and cables have a definite maximum life, which depends on car speed, meters travelled, and original type of cable.

If one cable is wearing, all cables have to be replaced at the sometime. This is necessary so that all the cables will have the same stretch characteristics and is why old and new cables cannot be mixed.

“The car moves in the shaft, the vertical passage from the top to the bottom of the building. The upper part of the shaft is called the pent house, and the lower ports called the pit. The penthouse covers the elevator machine and the pit is below” the lowest serviced floor. Shaft floor doors are located at each serviced level.

The shaft also includes guide rails, the vertical track system for car movement. Roller guide shoes attached to the car ride on the guide rails. Proper lubrication is necessary for quiet car movement. Roller guide bearings may have to be replaced, and the shoes may have to be adjusted to ensure quiet and vibration- free car movement.