The electrical ground bus bar provides a central, reliable point where all ground wires in a system are connected. Common methods of protecting busbars include overcurrent-based interlocking schemes, overcurrent-based differential protection, high-impedance differential protection, and percentage differential protection. If the fault occurs on A, then the B will operate. The operating times of the relay will be 0. Such system is mainly used for the. A busbar is a high-conductivity metallic conductor used in substations to transmit electrical current and distribute power across various connected equipment like circuit breakers, transformers, and generators. For substations with terminals capable. DEFINITIONS.