The doors of a box-type substation should open outward and have handles, concealed latches, and locks. The concealed latches and locks should be rust-resistant. The transformer room should primarily rely on natural ventilation, and a curve showing the relationship between the internal temperature and transformer output should be provided. The transformer room may be equipped with a room temperature monitoring device and a self-actuating ventilation and cooling device, as needed, to ensure the transformer operates at full load under specified environmental conditions. The transformer should be accessible through the top or side doors. The noise level of a box-type substation should not exceed the specified transformer noise level. Whether the box is made of metal or non-metallic materials, the metal frame of the box should be well grounded, with a grounding terminal and a clearly marked grounding symbol.
Box-type substations primarily rely on natural air circulation for cooling. Therefore, no illegal objects should be piled around them, especially the transformer room door should not be blocked. Ventilation louvers should be regularly cleared of debris to ensure that all electrical equipment does not exceed the maximum allowable temperature. If a low-voltage circuit breaker trips, the cause of the trip should be investigated before re-energizing. If re-energizing fails, the cause must be thoroughly investigated and corrected before re-energizing to prevent further damage. Zinc oxide lightning arresters should be installed in the high-voltage distribution room of a box-type transformer. The installation method must facilitate testing, installation, and replacement.
The grounding and neutral lines of a box-type substation share a common grounding grid. This grid is typically connected to the grounding grid by driving grounding stakes at the four corners of the foundation. The box-type substation must have two reliable connections to the grounding grid. After the box-type substation is in operation, the grounding connections should be regularly inspected to ensure they are not loose or corroded. The grounding resistance should be measured regularly and should not exceed 4Ω. The ring network switches, transformers, lightning arresters, and other equipment in the box-type substation's high-voltage distribution system should be regularly inspected and maintained, with defects promptly repaired. Regular insulation preventive testing should also be performed. A box-type substation that has been out of service for more than three months should undergo a full preventive test before re-commissioning. When replacing a high-voltage fuse without breaking capacity, the transformer must be disconnected from power. The mechanical interlock must be properly disengaged during the operation, and an insulated operating rod must be used.
All inlet and outlet cable holes of the box-type substation should be sealed to prevent small animals from entering and causing accidents.
The floor for a box-type substation should be located at a high level, not in a low-lying area, to prevent rainwater from entering the substation and affecting equipment operation. When pouring the concrete platform, leave gaps between the high- and low-voltage sides to facilitate the routing of incoming and outgoing cables. When excavating the foundation, if the ground is composed of accumulated garbage or rotten soil, dig down to solid soil, then backfill with good quality soil and tamp it firmly before filling with cement or ballast to ensure a stable foundation.