How does a VFD control the speed of an electric motor?
A. By changing the voltage and frequency of the electrical supply to the motor
B. By changing the current flowing to the motor
C. By adjusting the mechanical components of the motor
D. By changing the resistance of the motor
Answer:A
How does a VFD control the speed of an electric motor?
A. By changing the voltage and frequency of the electrical supply to the motor B. By changing the current flowing to the motor C. By adjusting the mechanical components of the motor D. By changing the resistance of the motor
Explanation: A VFD controls the speed of an electric motor by adjusting the voltage and frequency of the electrical supply to the motor. By changing the voltage and frequency of the electrical supply, the VFD can control the speed of the motor. This is known as “variable frequency control”. As the frequency of the electrical supply increases, the speed of the motor increases, and as the frequency decreases, the speed of the motor decreases.