ABSTRACT
This chapter emphasizes primarily the line of defence for a power system or a circuit, that is, fuses. Types of fuses, along with the material used for the fuse wires, are discussed. Factors affecting the performance of a fuse along with its disadvantages are also highlighted. Arc quenching is the most important issue to address while designing a circuit breaker. Hence, the arc quenching, possibilities, and factors responsible for the recurrence of an arc are also explained. In this chapter, types of circuit breakers are classified on the basis of their working voltages, and special emphasis is given to the SF6 type circuit breakers. Circuit breakers are given the task of breaking the circuit under abnormal conditions, and their high performance characteristics should be analysed and tested. Various testing methods are described in this chapter to improve reader understanding.
