Question 1

In a geared traction elevator, the hoist ropes are driven by:

Accepted Answer

Geared traction elevators use a motor connected through a worm gear or helical gear reducer to a drive sheave. The hoist ropes wrap around the sheave and support the car and counterweight. The gear reducer allows a smaller, faster motor to develop sufficient torque. Gearless traction elevators connect the motor directly to the drive sheave, requiring a larger, slower motor but offering quieter, more efficient operation at higher speeds.

Question 2

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

Accepted Answer

The counterweight balances the weight of the empty car plus approximately 40–50% of the rated load. This significantly reduces the net load the motor must lift, improving energy efficiency. The counterweight travels in the opposite direction of the car — when the car goes up, the counterweight goes down and vice versa, with both sides of the rope on the drive sheave.

Question 3

The Elevator Industry Field Employees' Safety Handbook requires mechanics to use LOTO (Lockout/Tagout) before:

Accepted Answer

OSHA's Lockout/Tagout standard (29 CFR 1910.147) and ASME A17.1 both require LOTO procedures before performing maintenance that could expose a worker to injury from unexpected startup or movement. This includes de-energizing and locking out main power, testing for zero energy, and applying personal locks before any maintenance work begins.

Question 4

The rope factor (sheave-to-rope ratio) in a traction elevator refers to:

Accepted Answer

ASME A17.1 requires a minimum D/d ratio (sheave diameter to rope diameter) of 40:1 for traction elevators. A smaller ratio causes excessive rope bending stress and accelerates fatigue. Larger sheaves extend rope life.

Question 5

A gearless traction machine differs from a geared machine primarily in that:

Accepted Answer

In a gearless machine, the hoist sheave is mounted directly on the motor shaft (typically a permanent magnet or induction motor), eliminating the gearbox. Gearless machines are used for high-speed applications and require less maintenance than geared machines.

Question 6

What is the purpose of the rope gripper (rope brake) in a machine-room-less (MRL) traction elevator?

Accepted Answer

The rope gripper (used in MRL elevators as an Unintended Car Movement Protection (UCMP) device) grips the hoist ropes to stop the car if unintended car movement is detected with doors open. It is required by ASME A17.1 for UCMP compliance.

Question 7

Traction is lost (car slips on sheave) when the balance ratio between car load and counterweight is incorrect. The counterweight is typically set to balance the car at:

Accepted Answer

The counterweight is typically designed to balance the empty car plus 40–50% of its rated capacity. This balance point minimizes motor work in both directions (carrying a full car up and an empty car down require similar motor effort).

Question 8

Safeties on a traction elevator car are activated by the:

Accepted Answer

The governor rope is attached to the car safety linkage. When the governor trips (due to overspeed), it grips the governor rope, which mechanically pulls the safety wedges or rollers into contact with the guide rails, stopping the car.

Question 9

An elevator machine room must maintain a minimum temperature of approximately:

Accepted Answer

ASME A17.1 requires the machine room to be maintained at a temperature range appropriate for the equipment (typically above 50°F/10°C minimum), with ventilation to prevent overheating. Extreme cold or heat affects controller and drive reliability.

Question 10

The traveling cable in a traction elevator connects:

Accepted Answer

The traveling cable is a flexible electrical cable that hangs between the car and the hoistway, connecting the moving car to the fixed controller and power supply. It carries power for car lighting, door operators, phones, and all car-mounted electrical devices.

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