NEIEP Mechanics Practice Exam

What function do the motor contactors serve on a hydraulic elevator?

1. They run the car in the up direction

2. They control the speed of the elevator

3. They monitor the safety features

4. They assist in emergency braking

The correct answer is: They run the car in the up direction

Motor contactors play a crucial role in the operation of hydraulic elevators by providing a means to control the direction of the elevator car. When the contactors are energized, they allow electrical power to flow to the motor that drives the hydraulic pump, which in turn raises the elevator car. Essentially, motor contactors act as electrically-operated switches that engage and disengage the electrical supply based on the control signals from the elevator's operating system. The function of running the car in the up direction is vital for the operational efficiency and user experience of the elevator. The system must be able to control the motor's direction for proper ascent and descent of the elevator car, ensuring that it operates smoothly along its designated path. Understanding this function is foundational, as it illustrates how the components of an elevator work together to provide safe and reliable transportation. The other options highlight different functions that may be important in the elevator system but do not accurately define the primary purpose of motor contactors.