The distribution box shall be embedded in the wall. When the wall is built, the reserved hole shall be about 20 mm larger than the length and width of the distribution box. Covers wiring, placement, standards, and expert tips for a compliant setup. Punch out holes in box in areas indicated on the front view drawing by. An electrical distribution box, also known as a power distribution box, panelboard, or consumer unit, is the core of an electrical system. Various capacities, materials, locking and mounting options are available. A wide range of the applicable LSA-PLUS® accessories can be used as well as.