1 describe the similarities and differences between the

Question

1. Describe the similarities and differences between the three different types of polyphase AC motors.

2. Describe five (5) benefits of using a 3-phase motor compared to a single-phase motor.

3. Sketch the torque speed curve of an induction motor and identify the following points on the graph:

• Breakaway starting Torque
• Pull-up Torque
• Pull-out Torque
• Full load Torque

4. What are the three (3) main components of a DC motor? Explain each component.

5. What are the main losses in an induction motor (name and briefly explain) and how the efficiency is calculated?

6. List and explain the seven (7) parameters that must be monitored to ensure the motor is in good condition.

7. List and explain the four (4) parameters that must be monitored to ensure motor bearings are in good condition.

8. List and explain the parameters that can cause insulation failure in an electric motor.

9. What are the six (6) features of ideal motor protection relays?

10. What are the four (4) main areas of a typical VSD control system?

11. List and explain the mechanical failures and auxiliary failures in an electric motor.

12. What are the three (3) common cabling errors made when installing VSD's?

Answer 1

By using and applying the concepts of Electrical engineering, answer the following questions in a detailed manner, you can as well comprise diagrams wherever required. Q1. Illustrate the similarities and differences between the three different kinds of polyphase AC motors. Q2. Explain five advantages of employing a 3-phase motor as compared to the single-phase motor. Q3. Draw the torque speed curve of the induction motor and recognize the given points on the graph: • Breakaway starting Torque • Pull-up Torque • Pull-out Torque • Full load Torque Q4. Describe the three major components of the DC motor? Describe each component. Q5. Describe the major losses in the induction motor (name and in brief describe) and how the efficiency is computed? Q6. List and describe the seven parameters which should be monitored to make sure the motor is in good form.