Three‐phase reclosers are used when it is necessary to disconnect all three phases in order to prevent unbalanced loading on the system. In lightning protection, the surge protection device in distribution boxes plays a crucial role. According to the principle of graded lightning protection, and based on the likelihood of a building being struck by lightning, it is necessary to deploy surge protector against lightning in stages to. Temporary power supply at the construction site should adopt a three-tiered distribution system, with the main distribution cabinet, distribution boxes, and switch boxes arranged according to regulations to achieve a rational layout of electrical facilities at each level. The first level is the main distribution cabinet, the second level is the sub-distribution cabinets, and the third level is the switch box. In addition to installing leakage protectors in the final switch box, a first level leakage protector should also be installed. This paper discusses basic electrical dis-tribution maintenance concepts, including the purpose and characteristics of different types of maintenance, frequency of maintenance intervention, and spare parts policies. Why maintain electrical distribution equipment? Carrying out maintenance in. To eliminate safety hazards as fast as possible To limit service outages to the smallest possible segment of the system To protect the consumers' apparatus To protect the system from unnecessary service interruptions and disturbances To disconnect faulted lines, transformers, or other apparatus.
