Electrical Railway Protection 65KA 100KA Lightning Arrester

65KA 100KA Lightning arrester for electrified railway protection

Measurement of insulation resistance of lightning arrester

The measurement of insulation resistance, for the FS-type lightning arrester, is mainly to check the seal situation, if the seal is not strict will inevitably cause internal dampness, so that the insulation resistance obviously decreased. In accordance with the pre-test procedure, the measurement shall be carried out by testing the 2500V megabyte meter, and the insulation resistance shall be not less than 2500M. Clean the surface of the lightning arrester before testing, otherwise the leakage current on the coat surface will affect the accuracy of the test. For this purpose, the surface of the porcelain cover should be cleaned with a clean, absorbent cloth before the test, and a thin metal wire is used to circle the underside of the first underskirt of the coat, which is then connected to the mew watch "shield" terminal column to eliminate the effect. In the test, the Meow watch should be connected with the lightning arrester as short as possible and the electrical contact should be good. The mew watch should be placed horizontally, the speed should be uniform, and 120 revolutions per minute should be used to obtain good measurement results.

For FZ lightning arrester, in addition to checking whether the interior is damp, check whether the shunt resistor is broken and aging, if the shunt resistor is old and broken, because of poor contact, the insulation resistor will increase. To ensure that measurements are accurate, measurements should be made twice and the data should be compared for any changes. Measurement should be done using the same meioEurope meter at the same voltage level, otherwise comparison is not possible.

DC 1 mA reference voltage test

Apply 0.75 times 1 mA DC voltage(DC voltage pulsation rate not greater than 1.5 %) to both ends of the arrester when the current through the arrester is stabilized at 1 mA. The voltage at both ends of the lightning arrester shall not be less than 25 kV.

DC Leakage Current Test
After 0.75 times 1 mA DC voltage is applied at both ends of the lightning arrester at test time, the leakage current passing through the lightning arrester should not be greater than 50mA. During the test, when the leakage current reaches 30 Mu A and the voltage continues to increase, the leakage current will increase sharply. In order to prevent the effect of leakage current on the surface of the ceramic cover, the outside surface of the cover should be cleaned with a cloth with good absorbency before testing to eliminate the effect.

Measurement of conductance current of lightning arrester with parallel resistance