What does a Variable Frequency Drive (VFD) motor control?

A Variable Frequency Drive (VFD) primarily controls the frequency and voltage supplied to an electric motor, which directly influences the speed and torque of the motor's operation. By varying the frequency of the electrical input, the VFD adjusts the speed of the motor; if the voltage is also adjusted accordingly, it can maintain optimal performance and efficiency.

Understanding the function of a VFD is crucial for applications requiring precise control of motor operations, such as pumps, fans, and conveyors. The ability to vary frequency allows for better energy efficiency since motors can operate closer to their required speed rather than running at full speed and dissipating excess energy as heat. This capability makes VFDs essential in many industrial applications for energy savings and process control.

In this context, while other options mention factors such as temperature, pressure, flow, and elevation, they do not accurately encompass the core operational control offered by a VFD in relation to electric motor output.