Summary of Three-Tier Power Distribution System: Primary: The main distribution panel, supplies power from the transformer. In a newly constructed residential area, a 10kV power line is introduced into the substation. 4kV), power distribution is achieved through three levels of distribution boxes: the main distribution board, secondary. 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. Incorporates a complete protection system (e. Power distribution hierarchy in building. detailed explanation of DB, SDB, MDB, RMU, and Switchgear along with any commonly related equipment you might have missed, including their purpose, application, and hierarchy in an electrical distribution system.