Diploma in EEE Study Material | CONTROL OF ELECTRICAL MACHINES Unit 2 | Yuvasallinfo
Diploma in EEE Study Material | CONTROL OF ELECTRICAL MACHINES Unit 2 | Yuvasallinfo
CONTROL OF ELECTRICAL MACHINES Study Material, Diploma Study Material given Below:
RATIONALE
Various control operations are to be performed on the electrical machines to suit the industrial requirements. Technician is mainly employed to look after the control panels. To make our students employable, they have to be trained in using various control components and circuits. This subject fulfils that requirement.
OBJECTIVES
To understand Electrical control circuit elements including various types of industrial switches, relays, timers, solenoids, contactors and interlocking arrangement. AC motor control circuits for acceleration control, speed control, direction control, braking control and jogging using contactors. Different control circuits for industrial applications. Basics of programmable logic controller. PLC Programming.
For More Details Visit:
CONTROL OF ELECTRICAL MACHINES
AC MOTOR CONTROL CIRCUITS
Unit 2 Important 2 Marks
1. How will you connect retaining contact in DOL starter?
2. Draw the current speed characteristics of AC motor during acceleration.
3. What is the function of autotransformer in autotransformer starter?
4. What is open circuit transition in autotransformer starter?
5. What is closed circuit transition in autotransformer starter?
6. State whether surge current is available or not in the closed circuit transition.
7. Why the autotransformer starters are rarely used?
8. List the types of star delta starter.
9. Name the type of timer used in automatic star delta starter.
10. What is the function of interlock contact in star delta operation?
11. What do you mean by toggle time in star delta starter?
12. How many leads are to be brought out from the motor while using star delta starter?
13. How will you reverse the direction of rotation of 3 phase induction motor?
14. How will you identify the main contacts in a contactor?
15. How many speeds are possible in pole changing motor?
16. Which braking causes less heat generation?
17. How is dynamic braking effected in induction motor?
18. What is the usual method of wound rotor connection?
19. State whether wound rotor is connected in star or delta.
20. List any two applications of rotor resistance method of starting in slip ring
induction motor.
21. What will be the rotor frequency at the time of starting slip ring induction motor?
22. Which motor is started by using secondary frequency acceleration starter?
Unit 2 Important 3 Marks
1. Draw the circuit diagram of DOL starter.
2. Write a note on electric braking.
3. Write a note on open circuit transition in star-delta starter.
4. Compare a automatic and semi automatic star delta starter.
5. What is the need of sealing contact? Explain.
6. Write a note on interlock contact.
7. Write a note on sequential interlock contact.
8. Write a note on closed circuit transition in auto transformer starter.
9. What are the methods of starting cage induction motor?
10. How do you reverse the direction of induction motor?
11. What are the electrical braking methods recommended for induction motor?
12. What do you mean by dynamic braking in cage induction motor?
13. What do you mean by two speed controller of cage induction motor? Where is it used?
14. List the applications of slip ring induction motor.
Unit 2 Important 10 Mark Questions
1. Explain the control circuit and main circuit of DOL starter.
2. Explain the control circuit and power circuit of autotransformer starter.
3. Draw and explain the control circuit and main circuit of auto transformer open circuit
transition starting of cage induction motor.
4. Draw the control circuit for autotransformer starter of closed circuit transition and
explain.
5. Draw and explain the control circuit and main circuit of semi -automatic star-delta starter.
6. Draw and explain the control circuit and main circuit of automatic star delta starter.
7. Draw and explain the control circuit of two speed control in induction motor.
8. Explain the control circuit for reversing the direction of three phase induction motor.
9. Explain the control circuit and main circuit for dynamic braking of cage induction motor.
10. Explain the control circuit for automatic rotor resistance starter for three phase slip ring
induction motor.
11. Explain the control circuit for the operation of secondary frequency acceleration starter.