A contact bus bar assembly for supplying power to a load, and further pertains to a switching device which can be connected to such a compact bus bar assembly, and to a power distribution system. The bus bar assembly includes at least two electrically conductive tracks which are at least partly covered by an electrically insulating cover. An outer surface of said insulating cover is provided with a plurality of ribs arranged in a region connecting pin terminals. The switching device may additionally comprise a separating element provided with a plurality of second ribs.