Circuit Breakers Interview Questions:
Following are the below Circuit Breakers Interview Questions and Important Questions which is very useful for interviews and exams
1. What are the different types of circuit breakers when the arc quenching medium is the criterion ? Mention the voltage range for which a particular type of circuit breaker is recommended.
2. Explain the principle of circuit interruption. State the various types of circuit breakers used for HV and EHV systems.
3. Classify circuit breakers. Explain the basic difference between bulk oil circuit breaker and minimum oil circuit breaker.
4. Explain the construction, principle and working of an oil circuit breaker with a neat sketch.
5. Discuss the principle of arc extinction in an oil circuit breaker with reference to restriking and recovery voltages.
6. Explain how an arc is initiated and sustained in an oil circuit breaker (CB) when the CB contacts separate. Also explain the terms : Restriking voltage, Recovery voltage, Rate of rise of restriking voltage.
7. Explain with the help of a neat sketch the function of a plain explosion pot. What are its advantages over the plain break circuit breaker ? What are its limitations ?
8. Discuss the process of arc extinction in an oil circuit breaker. Draw a neat sketch of an oil circuit breaker and explain its working.
9. Show under what distribution of capacitance in a double break type plain-break oil circuit breaker, will about 83.4% of the total voltage appear across the break nearer to the source of supply.
10. Describe with a neat sketch the working of cross-jet explosion pot in bulk oil circuit breakers.
11. Enumerate the advantages of minimum oil circuit breaker over the bulk oil circuit breaker.
12. Describe with a neat sketch the principle of operation of a minimum oil circuit breaker. Why is it called so ?
13. Describe the construction and operation of a minimum oil circuit breaker.
14. Explain the construction, principle of operation and application of a minimum oil circuit breaker.
15. Explain the features of an air break circuit breaker by means of simple sketches.
16. What are the advantages and disadvantages associated when air is used as an arc quenching media instead of oil ? Discuss with necessary circuit diagram the principle of operation of an air-break circuit breaker with magnetic blow-out coil and “arc chute” used for 11 kV system.
17. With a neat sketch explain the principle of operation of an air-break circuit breaker. Why an arc chute and a blow-out coil are used in a circuit breaker ? Explain briefly why is it easier to break current in an ac circuit breaker than in a dc circuit breaker ? What technique is adopted for dc circuit breaker?
18. Discuss the principle of arc interruption in (i) an oil circuit breaker (ii) air blast circuit breaker.
19. Explain with necessary diagram the phenomenon of current chopping in an air blast circuit breaker. How this problem can be rectified by using resistance switching ? Why mostly air blast circuit breakers are susceptible to current chopping ?
20. What are the usual methods of arc quenching in a circuit breaker ? Why arcs are formed during breaking of large currents ?
21. What is the difference between cross-blast and axial-blast technology in air blast circuit breaker? Show with a neat sketch the air blast mechanism used there.
22. Discuss with a neat sketch the principle of operation of an axial blast circuit breaker and hence explain why an air blast circuit breaker is very much susceptible to current chopping ?
23. Explain the working of an air blast circuit breaker with the help of suitable diagram.
24. Explain current chopping phenomenon associated with ABCB.
25. Discuss the following circuit breakers : (i) Air blast circuit breaker (ii) SF6 circuit breaker.
26. Draw appropriate diagrams to show the complete operation of a SF6 circuit breaker. Give the merits of SF6 circuit breakers.
27. Describe the construction, principle of operation and applications of SF6 circuit breaker. How is it different from air blast circuit breaker ?
28. Explain the SF6 circuit breaker. What are its advantages and disadvantages over air blast circuit breaker ?
29. Discuss briefly, the construction, principle of operation and applications of SF6 CB.
30. Explain the construction and working of a puffer type SF6 circuit breaker. Also enumerate the properties of SF6 gas which make at a good dielectric and arc quenching medium.
31. Draw appropriate diagrams to show the complete operation of a SF6 circuit breaker. Give the merits of SF6 circuit breakers.
32. Describe the working principle of a vacuum circuit breaker. How contact movement and electrical connections with the contacts are made in a vacuum circuit breaker ? What are the shortcomings of a vacuum circuit breaker ?
33. Discuss the behaviour of electric arc in vacuum with the help of a neat diagram. Explain the construction of a vacuum circuit breaker.
34. Discuss the merits and demerits of a vacuum circuit breaker for low voltage applications.
35. Discuss the problems encountered in HVDC circuit breaking. Suggest remedies for them.
36. Explain with a suitable example the phenomenon of autoreclosing.
37. What are the special features of an autoreclosing CB ? What are its advantages ?
38. Name different types of circuit breakers with their relative merits.
39. Compare the performances and characteristics of (i) minimum-oil breakers and air blast circuit breakers (ii) air blast circuit breaker and bulk oil circuit breaker.
40. Compare the performance and characteristics of minimum oil breakers and air blast circuit breakers.
41. What are the merits and drawbacks of air blast circuit breakers over bulk oil circuit breakers.
42. Compare vacuum and SF6 circuit breakers.
43. Write short notes on the following :
- Oil circuit breakers.
- Minimum oil circuit breaker.
- Air circuit breaker.
- Air blast circuit breaker.
- SF6 circuit breakers.
- Constructional details and principle of operation of SF6 circuit breaker.
- Vacuum circuit breakers.
- Oil circuit reclosers.