Chapter 7, Problem 7.1MCQ

Derive an expression for fault current for single line-to-ground fault by symmetrical components method.Derive an expression for fault current for line-to-line fault by symmetrical components method.Derive an expression for fault current for doube line-to-ground fault by symmetrical components method.

Which among these statements are false or incorrect? A. In the Duplicate Busbar System, continuity of service is possible even if the Main Busbar is undergoing maintenance, by switching the connections to the Spare Busbar. B. In the Ring Busbar System, there are the same number of circuits and breakers. C. When sectionalizing a Single Busbar, load is equally distributed to all sections. D. During maintenance, some lines being supplied by the Ring Busbar System will lose continuity of supply. Clear my choice

True False Bonding must be accomplished around conduit connections whenever the fault current return path is suspect as well as when specifically required by the NEC

Obtain the thévenin sequence impendance for the fault of bus 2 and compute the fault current in per unit for the  a) A bolted single line-to-ground fault at bus 2.

24. In Single Busbar System with Bus Sectionalization, any two sections of the Busbar are connected via Circuit Breaker and Isolators. Select one: True False

It is generally understood that grounding and bonding together all metal parts of an electrical system and the metal shield of the cable television cable to the same grounding reference point in a residence will keep both systems at the same voltage level should a surge, such as lightning, occur. Therefore, if the incoming cable that has been installed by the CATV cable company installer has the metal shield grounded to a driven ground rod, does this installation conform to the NEC? ___________