Air-Insulated Substations: Bus/ Switching Configurations 3.1 Introduction ..................................... 3-l 3.2 Single Bus Arrangement...................................... 3-l 3.3 Double Bus-Double Breaker Arrangement.......... 3-2 3.4 Main and Transfer’ Bus Arrangement 3-3 3.5 Double Bus—Single Breaker Arrangement........ ........3-4 3.6 Ring Bus Arrangement 3-5 3.7 Breaker-and-a-Half Arrangement 3-5 3.8 Comparison of Configurations 3-7