Elevator Mechanic Practice Exam

What component keeps a DC motor from slipping through the brake in a Ward-Leonard system?

1. Coil voltage regulator

2. Integrator relay

3. Load balancing circuit

4. Suicide Circuit

The correct answer is: Coil voltage regulator

In a Ward-Leonard system, the component that keeps a DC motor from slipping through the brake is the coil voltage regulator. This component is crucial because it maintains the required voltage level to the motor's field windings, ensuring consistent electromagnetic force to hold the motor stationary when it is not in operation. This regulation helps prevent slippage, particularly when the motor is under load or when braking is necessary. Other options do exist, but they serve different roles. The integrator relay primarily influences motor control dynamics, while a load balancing circuit distributes power efficiently among multiple motors or loads, and the suicide circuit is generally a safety mechanism that disconnects power in case of certain fault conditions. None of these alternatives directly address the necessity of preventing motor slippage in the way that a coil voltage regulator does.