OSHA and the National Electrical Code (NEC) specify the minimum clearance distances required around electrical panels. These include a depth of 36 inches, a width of 30 inches, and a height of 78 inches. Distribution box and switch box should not exceed 30 meters. Generally, distribution boxes can. The distribution box (cabinet) is suitable for temporary power supply at the construction site and should meet the requirements of "three-level power distribution, two-level leakage protection, one machine one switch, one leakage one box" for power distribution and protection. While the IEC 60364 standard. (3) Power distribution from tertiary switch boxes to electrical equipment must follow the “one machine, one switch” principle, with no branching allowed.
