A server rack assembly receives a plurality of servers. The server rack assembly includes a server rack, a bus-bar, and a power supply. The server rack includes a stand column. The server rack defines a plurality of server spaces for receiving the plurality of servers. A bus-bar is mounted to the server rack and includes a plurality of connectors aligned in a first direction substantially parallel to the stand column. The bus-bar is adapted to electronically plug to the plurality of servers. The power supply device is electronically connected to a middle portion of the bus-bar. The power supply device is adapted to output direct current to the bus-bar.