CET Elevator Installation & Components 3

Question 1

What is the primary purpose of elevator buffers located in the pit?

Accepted Answer

Absorb and dissipate kinetic energy if the car or counterweight overruns the terminal landing

Answer

Buffers (spring or oil type) are designed to decelerate and stop the car or counterweight in the event of overtravel beyond the terminal landing.

Question 2

What is the function of the car sling (frame) in an elevator installation?

Accepted Answer

Carries the suspension ropes and transmits loads to the car platform and safety device

Answer

The car sling is the structural steel frame that suspends the car platform, mounts the guide shoes, and incorporates the safety device plank.

Question 3

In a 2:1 roping arrangement, how does the rope speed compare to car speed?

Accepted Answer

Rope moves at twice the car speed

Answer

In a 2:1 roping system, the sheave on the car or counterweight acts as a movable pulley, so the rope must travel twice the distance the car travels.

Question 4

What type of safety device is activated by the governor and clamps the guide rails to stop a descending car?

Accepted Answer

Progressive or instantaneous safety

Answer

Governor-operated safeties (instantaneous or progressive type) grip the guide rails and bring the car to a controlled stop when overspeed is detected.

Question 5

What is the purpose of compensation ropes or chains in a high-rise traction elevator?

Accepted Answer

Compensate for the changing rope weight imbalance as the car moves through its travel

Answer

As the car rises, the hoist ropes on the car side become shorter and heavier on the counterweight side; compensation ropes hang below both to equalize this imbalance.

(CET) Certified Elevator Technician Practice Test

(CET) Certified Elevator Technician Practice Test

CET Elevator Installation & Components 3