Maintenance of arrester

In daily operation, the pollution status of the porcelain jacket surface of the arrester should be checked, because when the porcelain jacket surface is seriously polluted, the voltage distribution will be very uneven. In a shunt resistor arrester, when the voltage distribution of one of the components increases, the current through the shunt resistance will increase significantly, which may burn out the shunt resistance and cause a fault. 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 polluted, it must be cleaned in time.

Check the lead and ground lead of the arrester, there are burn marks and broken strands, and whether the discharge recorder is burned through this inspection, the most easy to find the invisible defect of the arrester; Check whether the seal at the top lead of the arrester is good, the bad seal of the arrester will cause water and moisture easily cause accidents, so check whether the cement joint at the connection of the porcelain sleeve and the flange is tight, and install a waterproof cover on the lead of the 10 kV valve type arrester to avoid rainwater infiltration; Check whether the electrical distance between the lightning arrester and the protected electrical equipment meets the requirements, the lightning arrester should be as close as possible to the protected electrical equipment, the lightning arrester should check the operation of the recorder after a thunderstorm; Check the leakage current, power frequency discharge voltage is greater than or less than the standard value, should be repaired and tested; The discharge recorder should be repaired when the number of operation is too much. There are cracks in the joint of porcelain sleeve and cement; Flanges and rubber pads should be repaired when they fall off.

The insulation resistance of the arrester should be checked regularly. When measuring, the 2500 volt insulated gauge is used. When the value obtained is compared with the previous result, it can continue to be put into operation if there is no significant change. When the insulation resistance decreases significantly, it is generally caused by poor sealing and moisture or short circuit of the spark gap. When it is lower than the qualified value, the characteristic test should be carried out; When the insulation resistance increases significantly, it is generally caused by poor contact or fracture of the internal parallel resistance, spring relaxation and internal component separation.

In order to find the hidden defects in the valve arrester in time, a preventive test should be carried out before the annual thunderstorm season.