Traction Drive Systems and Wire Rope Flashcards

What parameter must a QEI inspector verify when checking drive sheave groove condition?

Answer: Groove wear and undercut depth relative to manufacturer limits

Inspectors must measure sheave groove wear and undercut to ensure ropes seat properly and traction is maintained within manufacturer and code limits.

Which test verifies that the elevator braking system can hold the car with its rated load?

Answer: Brake torque test

The brake torque test confirms the elevator brake can hold the car stationary with full rated load applied, as required by ASME A17.1.

What is the ASME A17.1 requirement for traction elevator counterweight balance relative to the car?

Answer: Counterweight equals car weight plus 40% to 50% of rated load

ASME A17.1 requires the counterweight to equal the empty car weight plus 40–50% of rated capacity to optimize traction and energy efficiency.

What does a 'traction loss' condition occur when in a traction elevator?

Answer: The friction between the hoist ropes and drive sheave is insufficient to move the car

Traction loss occurs when the friction force between the hoist ropes and sheave grooves cannot overcome the load difference, causing the ropes to slip.

Under ASME A17.1, what is the minimum factor of safety required for elevator hoist ropes?

Answer: 10

ASME A17.1 specifies a minimum factor of safety of 10 for elevator wire ropes used in passenger and freight elevators.

Which condition would require a QEI inspector to flag the drive machine for corrective action?

Answer: Excessive gear backlash in a geared machine beyond manufacturer tolerances

Excessive gear backlash beyond manufacturer tolerances indicates gear wear that can cause rough operation, noise, and eventual failure requiring corrective action.