CET CET Roping & Counterweight Systems

Question 1

What is the standard minimum number of hoist ropes required for a traction elevator under ASME A17.1?

Accepted Answer

3

Answer

ASME A17.1 requires a minimum of three hoist ropes for traction elevators to provide redundancy and safety against rope failure.

Question 2

What is the purpose of the counterweight in a traction elevator system?

Accepted Answer

Offsets the weight of the car and a portion of the rated load to reduce motor energy consumption

Answer

The counterweight balances the car weight plus approximately 40–50% of the rated load, significantly reducing the energy required to drive the elevator.

Question 3

What percentage of rated load is typically added to the car weight when calculating counterweight mass?

Accepted Answer

40–50%

Answer

Counterweights are typically set to equal the car weight plus 40–50% of the rated capacity to minimize motor loading in both directions.

Question 4

In a 1:1 roping arrangement, how does the rope travel distance compare to car travel distance?

Accepted Answer

Rope and car travel the same distance

Answer

In a 1:1 roping arrangement, the hoist rope and the car move the same distance for every rotation of the drive sheave.

Question 5

What is the advantage of a 2:1 roping arrangement compared to a 1:1 arrangement?

Accepted Answer

Greater mechanical advantage allowing a smaller motor to lift heavier loads

Answer

A 2:1 roping arrangement provides mechanical advantage, effectively doubling the lifting force of the motor at the cost of half the car speed.

(CET) Certified Elevator Technician Practice Test

(CET) Certified Elevator Technician Practice Test

CET CET Roping & Counterweight Systems