Advanced VFD Quiz 1

What is synchronous speed?

• The speed at which the motor's stator field rotates.

• The speed at which the cage spins in a synchronous motor.

• The maximum speed of a DC motor regardless of frequency.
• The speed at which an AC motor operates under load.

Which two factors determine an asynchronous motor's speed when it is operated directly on the line?

• Voltage level and load current
• Motor size and insulation type
• Temperature and humidity levels
• Supply frequency and number of poles in the motor.

What is the term for the difference between a motor's synchronous speed and its actual shaft speed?

• Slip
• Frequency
• Load
• Real Torque

Which motor type's shaft turns at about the same speed as its stator field rotates?

• Induction motor
• Stepper motor
• Universal motor
• Synchronous motor or Servo motor

Which part of a VFD converts AC into DC current?

• Inverter
• Controller
• Filter
• Rectifier

Which VFD components switch DC on and off very quickly to create synthetic AC?

• Diodes
• Resistors
• Capacitors
• IGBTs (Insulated Gate Bipolar Transistors)

What is the technique called that VFDs use to produce synthetic AC?

• Phase Shift Keying (PSK)
• Amplitude Modulation (AM)
• Frequency Modulation (FM)
• Pulse Width Modulation (PWM)

How much continuous overload can a Movidrive B handle?

• 125% of rated current

• 100% of rated current
• 200% of rated current
• 75% of rated current

Which lettered part is where you can measure your DC link voltage?

Which lettered part is the power input (line in)?