It is assumed here that the transmission has multiple grounding points at wye connected transformer neutrals, located throughout the system. When this condition is satisfied, any arcing fault between a phase conductor and the ground will be supplied by zero-sequence currents originating in the neutral connection of the high-voltage transformer banks. We often refer to these neutral connections as the "sources" of ground current, since very little current would flow to the ground fault if there were no grounded neutrals to provide a complete circuit for the fault current. When there are multiple ground sources, the current flowing to the ground may be very large. Any current flowing to the ground contains zero-sequence components and, under grounded conditions, a zero-sequence voltage will be measured at any nearby relay installation. Negative-sequence currents and voltages will also be observed, and these are sometimes used by the protective system. However, most ground ...