Abstract: A support and electrical power supply device comprises a mounting plate supporting an electrical switchgear apparatus and housing branch conductors extending perpendicularly to a busbar. The branch conductors present identical lengths. The connection strips are arranged close to the opposite terminal parts of the branch conductors and comprise orifices arranged symmetrically with respect to the horizontal midplane of the mounting plate to enable fitting of the connection parts with the lineside terminals or the loadside terminals of the switchgear apparatus. Two connection possibilities of the switchgear apparatus are possible at the time of installation to achieve a lineside or a loadside power supply. The same mounting plate can also be used for supply of a single switchgear apparatus or of two switchgear apparatuses with opposite feeders.