Designed for local control with strict safety standards, such as "one device, one circuit breaker, one residual current device, and one box. The complete set of products can form a complete three-level protection system for construction electricity, achieving the goal of one machine, one switch, and one protection, which is very suitable for various standard engineering applications. The first level cabinet adopts bottom in and bottom. Primary distribution systems consist of feeders that deliver power from distribution substations to distribution transformers. Many feeders leave substation in a concrete ducts and are routed to a nearby pole.