Introduction to Switchgear and Protection Interview Questions:

Following are the below Introduction to Switchgear and Protection Interview Questions and Important Questions which is very useful for interviews and exams

1. Explain why fault currents are more than load currents ? What are the harmful effects of faults ? What is meant by fault level or fault MVA ? Explain.

2. Classify the different faults which occur in power systems. Which of these are more frequent ?

3. Differentiate between symmetrical and unsymmetrical faults. Explain different types of faults and discuss which is the most common amongst them.

4. Which types of faults are taken into account while determining the rating of the circuit breaker ?

5. What is symmetrical fault current and unsymmetrical fault current ? Which type of fault causes them ?

6. What are the principal types of faults in a power system ? In what way a fault may be harmful to the power system ?

7. Explain clearly the sources of short-circuit power in a power system and the nature of such power.

8. Explain briefly the role of protection in a power system. Describe the essential features of a protective relay with reference to reliability, selectivity, speed of operation and discrimination.

9. “Relay is the brain of protection.” Justify this statement using trip circuit.

10. What is a protective relay ? Explain the functional characteristics of a protective relay ?

11. Explain the process of fault clearing with the help of a neat diagram

12. What is meant by short circuit ? What are the possible causes of short circuit in a power system ? Explain the harmful effects of short circuit on a power system and state the steps to he taken to protect the equipment from such fault.

13. What are the causes of faults in power systems ? Explain why the fault studies are carried out ?

14. What is a zone of protection ? Discuss various zones of protection of a power system with the help of line diagram.

15. What are primary and backup protections ? What are various kinds of backup protections ?

16. Describe about primary and backup protection.

17. Differentiate the following with examples : Primary and backup protections.

18. Sometimes faults are not cleared by primary relay system because of trouble within the relay, under such conditions, what protection is required ? Explain it.

19. Write an essay about the nature, causes and consequences of faults in power system. Explain the basic essential qualities of a protective scheme.

20. What are the desirable features of a power system protection system ?

21. What are basic requirements of protective relaying schemes ?

22. What are the basic characteristics of a protective relay ? Explain clearly.

23. Write short note on faults on power system.