In addition to complying with the regulations of the power department during installation, acceptance, handover testing, commissioning, operation, and maintenance, prefabricated substations must comply with the following: Upon receipt, users should carefully inspect the equipment in accordance with relevant regulations. Products not immediately installed should be stored in an appropriate location according to normal operating conditions. Products should be lifted from the bottom using a dedicated lifting device. The product should be placed horizontally on a pre-prepared foundation, with four anchor bolts installed (a secondary pouring method may be used). The gap between the product base and the foundation should be sealed with cement slurry to prevent rainwater from entering the cable compartment. High and low voltage cables should be connected through the bottom sealing plates of the high and low voltage compartments. The gaps between the cables and the conduits should be sealed and waterproofed. Whether the high-voltage side of a prefabricated substation uses overhead or cable entry, a clearly visible breakout for the high-voltage entry should be located near the substation. This ensures that maintenance personnel clearly indicate whether the substation is energized and ensures their safety.
After installation or maintenance, prefabricated substations should undergo the following inspections and tests before commissioning. After installation or repair, the following inspections and tests should be conducted before commissioning. Check the substation interior for cleanliness. Check the operating mechanisms for flexibility. Check the switching of major electrical equipment for flexibility and reliability. Check the switching of electrical auxiliary contacts for reliability and accuracy. Check the correct operation of meters and relays. Check the correct ratios and wiring polarity of instruments and transformers. Check that all electrical mounting nuts are tightened and securely installed. Check that busbar connections are in good condition, and that supporting insulators and clamps are securely installed. Check that the electrical settings meet requirements, and that fuse core specifications are correct.
All components in a box-type substation must be maintained according to their respective technical requirements. If the transformer is oil-immersed, oil sampling and inspection should be performed at least annually as required. After 20 load or 2,000 no-load opening and closing operations, the contacts and arc extinguishing device wear of operating high-voltage switchgear should be inspected. Any abnormalities should be promptly repaired or replaced. If a low-voltage switchgear automatically trips, the cause should be investigated and analyzed. Operation can only resume after the fault has been corrected. Lightning arresters should be tested once a year before the arrival of the thunderstorm season. When inspecting high-voltage switchgear or performing overall repairs, the power supply to the substation must be cut off first.