Isolator Q1 connects busbar 1, Q2 connects busbar 2 of the corresponding field to circuit breaker Q3. 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. 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. In this article, we shall discuss some important. Recommended: Electrical and Automation Components & Resources (EBooks) If circuit breakers are installed in the outgoing feeders, short-circuits of the lines affect only the consumers attached to the faulted line, since the network protection disconnects the faulted line selectively.