Motor Drives Flashcards
A drive-mounted programming interface, handheld programmer, external laptop computer, or other computers on a data network can be used as programming devices to configure VFDs.
A) True
B) False
A) True
Speed and ___ are two physical quantities that must be controlled in a motor drive.
A) direction
B) temperature
C) torque
C) torque
The three basic categories of tasks necessary to maintain a VFD in proper operating condition are: keep it clean, keep it dry, and keep connection tight.
A) True
B) False
A) True
When using a VFD, a motor’s ramp-up speed can be adjusted to vary from a few seconds to more than ___.
A) 60 seconds
B) 120 seconds
C) 180 seconds
B) 120 seconds
Re-torquing is a good procedure to use to check the status of terminals that are held in place with bolts or screws.
A) True
B) False
B) False
Match the load characteristics that the VFD is required to deliver to each type of load.
I. Constant horsepower loads
II. Constant torque loads
III. variable torque loads
A) Fans, centrifugal blowers, and centrifugal pumps
B) Hoists, conveyors, mixers, and reciprocating or rotary compressors
C) Wheel grinders, large drilling machines, lathes, planers, and boring machines
A) III.
B) II.
C) I.
Which drive programming software feature displays drive parameters, such as voltage, current, frequency, speed, and power consumed?
A) Display drive status
B) Error messages and alarms
C) Parameter updates
C) Parameter updates
___ are installed on power lines feeding VFDs to lessen the effects of harmonics generated by the VFDs.
A) Line reactors
B) Load reactors
A) Line reactors
The ___ of a VFD establish(es) the speed, rotation direction, and stopping parameters for the motor.
A) control set points
B) factory preset parameters
C) incoming power source
A) control set points
Lower initial cost and easier installation are two advantages of a(n) ___ motor control system.
A) closed-loop
B) open-loop
B) open-loop
When considering the environmental concerns of VFD installations, factory enclosures should have a(n) ___ rating appropriate to the level of protection for the installation.
A) IEC
B) NEMA
C) NFPA
B) NEMA
A tachometer/generator produces a feedback voltage which is directly proportional to the ___ of the motor.
A) horsepower
B) speed
C) torque
B) speed
All VFDs are configured and programmed the same way.
A) True
B) False
B) False
Which programming software feature monitors and displays the value of all drive and motor parameters in real time?
A) Display drive status
B) Error message and alarms
C) Parameter updates
A) Display drive status
