(1) Primary power distribution equipment, collectively referred to as the power distribution center. These are centrally installed in the enterprise's substation, distributing electrical energy to lower-level power distribution equipment in different locations. This level of equipment is located close to the step-down transformer, therefore requiring higher electrical parameters and a larger output circuit capacity.
(2) Secondary power distribution equipment is a collective term for power distribution cabinets and motor control centers. Power distribution cabinets are used in situations where the load is relatively dispersed and there are fewer circuits; motor control centers are used in situations where the load is concentrated and there are more circuits. They distribute the electrical energy from a circuit of the previous-level power distribution equipment to the nearest load. This level of equipment should provide protection, monitoring, and control for the load.
(3) Final-level power distribution equipment is collectively referred to as lighting power distribution boxes. These are located far from the power supply center and are distributed, small-capacity power distribution equipment.
