A bus is a critical element of a power systems, as it is the point of convergence of many circuits-transmission, generation, or loads. Factors such as bus configuration, relay input sources, operating time, sensitivity, and existing facilities are important in selecting the type of bus protection system. Existing stations may not have the required relay input sources for bus protection. The guide has been prepared to assist in the effective application of relays for protection of power system electrical buses. The bus protection described refers only to protection at the bus location, independent of equipment at remote locations. Common bus arrangements and some special arrangements used in the United States are covered. |