Box-type substation installation and maintenance

Box-type substations shall comply with the requirements of the electric power department in terms of installation, acceptance, handover testing, commissioning, operation and maintenance. Should also pay attention to the following matters: The user should carefully check the receipt of goods in accordance with the relevant provisions, for products not immediately installed, should be in accordance with the normal conditions of use, stored in an appropriate place. The product should be lifted at the bottom of a special spreader. The product level is placed on the basis of prior work, and four anchor bolts are installed (secondary irrigation method is available). Then, the gap between the product base and the foundation is sealed with cement sand to prevent rainwater from entering the cable compartment. The high and low voltage cables are connected to the bottom plate of the high and low pressure chambers. The gap between the cable and the pipe is sealed and waterproof. On the high-voltage side of the box-type substation, whether it is using an overhead line or a cable entry line, an obvious visible break (such as a drop-type fuse) on the high-voltage side line should be provided near the substation. In this way, it is clear to the maintenance operator whether the substation is charged. To ensure the safety of maintenance operators. After the product is installed in place, it should be grounded reliably: the two main earthing terminals on the channel steel of the power station, the neutral point of the transformer and the shell, and the pile header of the arrester should be grounded directly by the installation department. The grounding should share a group of grounding devices, and the grounding resistance should be less than 4 ohms. The grounding lead from the grounding grid to the product should be no less than two.

After the box-type substation is installed or repaired, it should be tested and tested as follows before putting it into operation. After the product is installed or repaired, the following inspections and tests shall be conducted before the product is put into operation. Is the substation clean? Is the operating mechanism flexible? The main appliances are flexible and reliable. Whether the electrical auxiliary contact is on or off is reliable and accurate. Metering and relay operation are accurate. Instrument and transformer ratio and polarity of wiring are correct. Whether all electrical installation nuts are tightened and the installation is solid and reliable. Busbar connection is good, it supports insulators, clamping parts are installed reliably. Whether the setting value of the electrical appliance meets the requirements and whether the fuse fused specification is correct. Whether the contacts of the main circuit and the auxiliary circuit meet the electrical schematic requirements. The resistance of the product's internal protective grounding system should be less than 0.01 ohms. Each part shall be tested for withstand voltage in accordance with the appropriate voltage level.

All components in the box substation are maintained according to their respective specified technical requirements. If the selected transformer is oil-immersed, at least one oil sample analysis inspection shall be conducted every year as required. After the high-voltage switchgear in operation has been operated with 20 loads or 2,000 no-load closings and closings, the contact conditions and the degree of wear of the arc extinguishing device should be checked, and anomalies should be promptly repaired or replaced. After the low-voltage switchgear is tripped automatically, the cause of the tripping should be checked and analyzed. After waiting for queuing failure, it can be restarted. Arresters should undergo a preventive test each year before the thunderstorm season. When repairing high-voltage switchgear or overall maintenance, the substation incoming power must be cut off.