New IEEE Standard - Inactive-Reserved. Concepts of power bus protection are discussed in this guide. Consideration is given to availability and location of breakers, current transformers, and disconnectors as well as bus-switching scenarios, and their impact on the selection and application of bus protection. A number of bus protection schemes are presented; their adequacy, complexity, strengths, and limitations with respect to a variety of bus arrangements are discussed; specific application guidelines are provided. Breaker failure protection is discussed as pertaining to bus protection. Means of securing bus protection schemes against corrupted relay input signals are also included.