A double-busbar switchgear uses two main busbars running in parallel. Each circuit can connect to either bus, allowing power to switch between them without cutting off supply. This setup offers higher reliability and flexibility. Single Line Diagram The simple layout diagram of a substation is provided below in which two step-down transformers TR1 and. Busbar switchgear helps control and distribute electricity safely inside a power system. The choice between them affects cost, reliability, and how easy. Each power source and each outgoing line is connected to both busbars via one circuit breaker and two disconnectors, allowing either busbar to serve as the working or standby busbar.