Six common bus configurations in substations up to 345 kV
Single BusSectionalized BusMain and Transfer BusRing BusBreaker-And-A-HalfDouble Breaker–Double BusRelative Switching Scheme CostsThe breaker-and-a-half configuration consists of two main buses, each normally energized. Electrically connected between the buses are three circuit breakers and, between each two breakers, a circuit as diagrammed in Figure 7. The breaker-and-a-half configuration provides for circuit breaker maintenance, since any breaker can be removed from servic...See more on electrical-engineering-portal Cisco
Different Types of Network Switches - Cisco
There are two main categories of switches: modular and fixed configuration. There are variations among these categories of network switches, but the primary