Chapter 9

Question 1

How does pulse width modulation (PWM) create insulation problems for standard electric motors?

Answer 1

The leading edge of each PWM pulse begins with a voltage spike.

Question 2

What factors affect the power quality of an electric motor drive?

Answer 2

Voltage, frequency, and by whether a system is grounded or ungrounded.

Question 3

What conditions should be avoided when installing an electric motor drive in a location?

Answer 3

High temp, high humidity, dust particles/fibers in the air, corrosive or explosive vapors, constant vibration, and direct sunlight should be avoided.

Question 4

Define electromagnetic interference (EMI)

Answer 4

Also known as electrical noise, is the unwanted signals generated by electrical and electronic equipment.

Question 5

What are advantages of serial communication?

Answer 5

Less wiring, ability to monitor and control the electric motor drive from a central location.