Red Seal Instrumentation and Control Technician Practice Exam

Why are variable frequency drives important in industrial applications?

1. They increase the weight of motors

2. They reduce the lifespan of equipment

3. They help control motor speed and improve energy efficiency

4. They replace the need for electrical enclosures

The correct answer is: They help control motor speed and improve energy efficiency

Variable frequency drives (VFDs) play a crucial role in industrial applications because they facilitate the precise control of motor speed and torque by adjusting the frequency and voltage supplied to the motor. This capability allows for better management of processes that require varying speeds, leading to significant improvements in operational efficiency. By controlling the motor speed, VFDs can optimize energy usage, particularly in applications where equipment does not need to run at full speed continuously. This energy efficiency not only reduces operating costs but also minimizes strain on the equipment, allowing it to run cooler and longer, which can extend its lifespan. Moreover, VFDs can be programmed for various operational profiles, enhancing automation and control in manufacturing processes. The other options indicate effects or functions that are not associated with VFDs. For example, VFDs do not increase the weight of motors, nor do they inherently reduce the lifespan of equipment; in fact, they often improve the lifespan through better control. Additionally, while they can be part of the electrical system, they do not replace the need for electrical enclosures, which serve important protective roles in a facility's electrical setup.