Secondary distribution boxes, also known as sub-distribution boxes, generally serve specific power supply areas. These boxes have inner and outer doors, powder-coated exteriors, and are designed for safety and aesthetic appeal, with rainproof tops for outdoor work. From the transformer's low-voltage side (0. 4kV), power is distributed to a main distribution panel (primary distribution box). At this. The construction power distribution cabinet is designed specifically for the special situation of the construction site and complies with the relevant construction electricity specifications and standards of the construction department. These effects of wear, impact and the stress caused by atmospheric agents (bad weather, major.