Operation and maintenance of arrester

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 polluted, the voltage distribution will be very uneven. In the arrester with parallel shunt resistance, when the voltage distribution of one of the components increases, the current through its parallel resistance will increase significantly, which may burn out the parallel resistance and cause a fault. In addition, it may also affect the arc extinguishing performance of the valve arrester. Therefore, when the surface of the arrester porcelain sleeve is seriously dirty, it must be cleaned in time.

Check the lead and grounding lead of the arrester, there are burn marks and broken strands, and whether the discharge recorder has burned through this inspection, it is easiest to find the invisible defects of the arrester; check whether the upper lead of the arrester is well sealed. Water ingress can easily cause accidents. Therefore, it is necessary to check whether the cement joint between the porcelain sleeve and the flange is tight. A waterproof cover can be installed on the lead wire of the 10kV valve arrester to prevent rainwater from infiltrating; check the arrester and the protected electrical equipment. Whether the electrical distance between the equipment meets the requirements, the arrester should be as close as possible to the protected electrical equipment, and the operation of the recorder should be checked after the arrester after a thunderstorm; the leakage current should be checked. When the power frequency discharge voltage is greater than or less than the standard value, it should be repaired and test; when the discharge recorder operates too many times, it should be overhauled; if there are cracks in the porcelain sleeve and cement joints; if the flange and rubber pads fall off, they should be overhauled.

The insulation resistance of the arrester should be checked regularly. A 2500-volt insulation shaker is used for measurement, and the measured value is compared with the previous result, and it can continue to be put into operation if there is no obvious change. When the insulation resistance drops significantly, it is generally caused by poor sealing and damping or short-circuiting of the spark gap. When it is lower than the qualified value, a characteristic test should be carried out; when the insulation resistance rises significantly, it is generally due to poor contact or breakage of the internal parallel resistance. As well as spring relaxation and separation of internal components, etc.

In order to discover the hidden defects inside the valve arrester in time, a preventive test should be carried out before the thunderstorm season every year.