The Distribution Bus 'A', Model 3782-1, and Distribution Bus 'B', Model 3782-2, each consists of two three-phase distribution busses in parallel, installed in a full-height EMS module. These modules are used for the connection of the EMS motor/generator sets and loads as well as the protective relaying equipment for bus protection. The bus bars and inputs/outputs are opened at intervals by eight three-pole relays with normally open (NO) contacts. These relays can be operated by switches located on the module front panel or through the action of dc control relays or protective relays as part of a bus protection scheme. Each module has a dc bus, energized from an external dc power supply, to distribute power to the relay coils. Used together, these two modules create a complete parallel bus bar.