An electrical meter center comprises a horizontal bar section comprising horizontal bus bars, the horizontal bus bar section defining a first connection section for the horizontal bus bars and a second connection section for the horizontal bus bars, the second connection section being laterally distant from the first connection section; and a wall panel assembly for covering a horizontal bar section of an electrical meter center. The wall panel assembly comprises a wall panel vertically mounted within the electrical meter center in front of the horizontal bar section, wherein the wall panel comprising an access window for accessing the horizontal bar section; and an access window panel selectively mounted to the wall panel to at least partially close the access window thereby providing selective access to the horizontal bar section.