During normal operation, one of the bus bars (Bus A or Bus B) carries the entire electrical load. When maintenance or repair is required on one of the bus bars, the load can be transferred to the idle bus . In Simple words, a bus-bar is a common connection point or a node for multiple incoming and outgoing circuits such as power lines or feeders. As we know it is impractical to connect multiple conductors at one point. Hence we use bus bars, where these connections can be done spaciously and. Here, we provide an overview of common substation busbar configurations—Single Bus, Main and Transfer, Double Breaker/Double Bus, Ring Bus/Ring Main, and Breaker and a Half. Designing a substation involves not only the visible equipment and ratings but also the less apparent factors—operational. When a number of generators or feeders operating at the same voltage have to be directly connected electrically, bus-bars are used as the common electrical component. Bus-bars are copper rods or thin walled tubes and operate at constant voltage. The subsequent circuit breaker also has a three-phase design and.