Elevator Mechanic Practice Exam

In a Ward-Leonard system, if all three contacts close, what will happen?

1. The car will run at full speed

2. The car will stop immediately

3. The system will short out

4. The motor will stall

The correct answer is: The car will run at full speed

In a Ward-Leonard system, when all three contacts close, it essentially means that the system is allowing the maximum permissible voltage and current to flow to the DC motor. This arrangement is designed to ensure that the motor receives full power, enabling it to operate at its rated speed. The primary purpose of the Ward-Leonard control system is to provide smooth control of motor speed and torque for elevator operation. By closing all three contacts, you are effectively bypassing any resistance that would somewhat limit the motor's speed or torque, thus allowing the elevator car to ascend or descend at full speed. This is an expected and designed feature of the system, ensuring efficient and powerful operation when required. Other outcomes in the choices—such as stopping immediately, causing a short circuit, or stalling the motor—could occur only under different circumstances, such as failures or interruptions in the control system. However, in the context of all three contacts being properly closed, achieving full speed is the intended function.