Under the rated voltage, the current passing through the zinc oxide arrester is only below 10-5a, which is equivalent to an insulator. Therefore, it can isolate the working voltage and the disc has no spark gap. When the voltage of the metal arrester has a great influence on the voltage value (starting voltage) of the zinc oxide arrester, the valve plate "conducts" and discharges a large current through the valve into the ground. At this time, the residual pressure does not exceed the pressure of the protected equipment, which is the purpose of protection. From then on, when the action voltage drops below the action voltage, the valve automatically terminates the "lead" state and restores the insulation state. Therefore, arc burning and fire extinguishing are no problem.
The main components of the 10kV AC power system, terminal modules, zinc oxide and other resistors as the main components of the arrester. It has good volt-ampere characteristics, and the zinc oxide resistance film has low resistance under atmospheric overvoltage and working voltage. The residual pressure of the arrester is limited within the allowable value range, thus providing reliable protection for the protected equipment. Disc suspension insulators exhibit high resistance at the normal operating voltage of the arrester.
In order to make the arrester only flow a small current, the zinc oxide resistor has a large square wave flow, which can meet the requirements of absorbing overvoltage energy. The integral molding of the silicone rubber sheath, insulating tube and upper and lower gold appliances constitutes a complete arrester, which makes the arrester have good anti-pollution, explosion-proof and moisture-proof performance.
Leakage current meter is zero. The reasons for this phenomenon may be: the instrument shows a fault; the shielded wire is short-circuited with the ammeter. The treatment method is: beat the rice by hand to see if the card is dead and cannot be recovered, and the missing sheet should be added, repaired or replaced. The shielded wire is separated from the conductive part of the lightning rod and can be restored to normal.
The large leakage current meter means: According to the historical data, if the ammeter is found to be fully charged, it should be determined that there is a problem with the arrester, and it should be reported to the dispatcher immediately, and the arrester is used up, please check. The rupture discharge of the porcelain sleeve of the arrester. In the case of operating frequency, the arrester porcelain sleeve is used to ensure the necessary insulation level of the arrester. If the porcelain bushing is damaged or discharged, it will become a hidden danger of accidents in the power system. In this case, it should be stopped and replaced in time.