The proper installation of a distribution box involves placing it at the right height to ensure safety and convenience. 5 meters, which is convenient for operation and maintenance. The cable trunking box. The dimensioning of an electrical plant requires knowledge of different factors relating to, for example, installation utilities, the electrical conductors and other components; this knowledge leads the design engineer to consult numerous documents and technical catalogues. It involves the placement of breakers, contactors, busbars, terminals, protective devices, and wiring in a structured and safe. According to standards, the height from the bottom edge of a distribution box to the floor is generally 1.