Clearing Ground Fault Currents on Distribution Systems---600 Volts or Less

This paper deals with the proper overcurrent protection of grounded distribution systems of 600 volts or less with special reference to ground fault currents, that is, fault currents caused by insulation failure between a phase conductor and the conductor enclosure. A new language of communication is set up to distinguish the various grounding conductors in a system. The function of the neutral in clearing a fault is analyzed and the method of sizing it is outlined. Proper grounding of the system is shown to be intimately linked with proper overcurrent protection.