Listed series-rated equipment allows the branch-circuit breakers to have a lower interrupting rating than the main. What two sections of the National Electrical Code 2017 cover the marking of series-rated systems with the words CAUTION-SERIES RATED SYSTEM?

a) Classify the four categories of 3 phase power system faults we experience in our electrical power industry. b) Explain the emergence of such power systems fault as required in (question 1a)? c) Point out each type of fault specified under (a). d) Produce the (1D) design of the three-phase star connected faults stated under(b)

Explain the purpose and operation of circuit breakers in power systems and their importance in fault protection.

Why are circuit breakers and fuses ineffective in protecting against transient over voltage due to lighting and switching surges?