An arc resistant switchgear assembly is provided having a front wall, a rear wall, a bottom surface, an upper surface, a first side wall, and a second side wall opposed to the first side wall and spaced a first distance from the first side wall, with each of the first and second side walls having an upper portion and a lower portion, and with each of the first and second side walls having an inner and an outer surface, with at least the lower portion of both the first side wall and the second side wall having at least one blow-off panel detachably secured thereto by fastening means. Each of the panels is detachably secured to the outer surface of the side wall to which each is secured. The assembly has a vertical plenum formed directly adjacent both the first and the second side walls, with the outer surface of each of the first and second side walls defining an inner side wall of each of the vertical plenums. The outer surface of the first side wall defines the inner side wall of one of the vertical plenums and the outer surface of the second side wall defines the inner side wall of an adjacent vertical plenum.