In daily operation, the contamination of the surface of the porcelain sleeve of the arrester should be checked, because when the surface of the porcelain sleeve is seriously contaminated, the voltage distribution will be uneven. In a lightning arrester with parallel shunt resistors, when the voltage distribution of one of the components increases, the current through the shunt resistor will increase significantly, and the shunt resistor may be burned out to cause a malfunction. In addition, it may also affect the arc extinguishing performance of the valve type arrester. Therefore, when the surface of the arrester porcelain sleeve is seriously filthy, it must be cleaned in time.
Check the lead wire of the arrester and the grounding down conductor. There are burn marks and broken strands, and whether the discharge recorder burns through this aspect. It is most easy to find the invisible defect of the arrester; check whether the seal at the upper end of the arrester is good, and the seal of the arrester will be bad. If the water entering the water is easy to cause an accident, check whether the cement joint between the porcelain sleeve and the flange is tight. Install a waterproof cover on the lead of the 10 kV valve arrester to prevent rainwater from penetrating; check the arrester and the protected electric Whether the electrical distance between the equipment meets the requirements, the arrester should be as close as possible to the protected electrical equipment. The arrester should check the operation of the recorder after the thunderstorm. Check the leakage current. If the power frequency discharge voltage is greater than or less than the standard value, it should be repaired. And test; when the discharge recorder has too many movements, it should be repaired; there is crack in the porcelain sleeve and cement joint; when the flange and rubber mat are off, it should be repaired.
The insulation resistance of the arrester should be checked regularly. The 2500 volt insulation shaker is used for the measurement, and the value obtained from the side is compared with the previous one. If there is no significant change, the operation can be continued. When the insulation resistance drops significantly, it is usually caused by poor sealing and moisture or short circuit of spark gap. When it is lower than the qualified value, it should be tested for characteristic; when the insulation resistance is significantly increased, it is generally due to poor contact or fracture of internal parallel resistance. And spring relaxation and separation of internal components.
In order to detect invisible defects inside the valve arrester in time, a preventive test should be conducted before the annual thunderstorm season.