Follow key principles: no cross-level wiring, one machine-one switch, ≤30m box spacing, dry/ventilated installation for safe distribution. The principle of minimizing distribution distances means that the distances between distribution boards and switch boxes should be kept as short as possible. Distribution boards should be placed in areas where electrical equipment. The Unified Facilities Criteria (UFC) system is prescribed by MIL-STD 3007 and provides planning, design, construction, sustainment, restoration, and modernization criteria, and applies to the Military Departments, the Defense Agencies, and the DoD Field Activities in accordance with USD (AT&L). Generally, first level distribution does not allow direct use of electrical equipment, and second level distribution will be by power equipment because it is three-phase electricity, while third level distribution is mains electricity (220V). Dedicated space: The space equal to the width and depth of electrical equipment in addition to the space extending. It is fairly well understood that if an assembly short-circuit current rating above 10,000 amperes is desired, a Power Distribution Block or a Terminal Block with a high short-circuit current rating must be utilized. However, there is great confusion concerning the spacing requirements of these. Load capacity calculation: Determine the total power demand of industrial facilities, including continuous load (such as production lines, pumps) and intermittent load (such as maintenance equipment, temporary workstations), and calculate the rated current required for each power distribution box.