They're standard in MV distribution from roughly 7. 2 to 36 kV and are designed for outdoor or compact indoor siting—typical ratings include 630 A busbars with short‑time withstand up to 25 kA for 1 s. These features make RMUs the building blocks of dense urban rings. 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. This technical article explains six most common bus configurations used for distribution, transmission, or switching substations at voltages up to 345 kV. Presented single line diagrams and layouts are generalized since they depend on the type and voltage (s) of the substations. 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. We have several busbar arrangements employed in grid stations and substations; they include: This is the simplest arrangement of a substation as illustrated in figure 1 (a). In this complex system, a crucial component serves as the main.