Metal oxide arrester test selection scheme

1) Power plant and substation lightning arresters before the annual thunderstorm season

2) When necessary

1) Above 35kV, not less than 2500MΩ

2) 35kV and below, no less than 1000MΩ

Use 2500V and above megger

1) Power plant and substation lightning arresters before the annual thunderstorm season

2) When necessary

1) Must not be lower than the value specified in GB11032

2) The measured value of U1mA should be no more than ±5% compared with the initial value or the manufacturer's specified value.

3) The leakage current at 0.75U1mA should not exceed 50μA

1) Record the ambient temperature and relative humidity during the test

2) Shielded wire should be used for the wire for measuring current

3) The initial value refers to the measured value at the time of the handover test or the production test.

1) Newly put into operation 110kV and above will be measured once after 3 months of operation; once every six months; after one year of operation, once before the thunderstorm season every year.

2) When necessary

Measuring full current and resistive current at operating voltage
Or power loss, the measured value is compared with the initial value. When there is a significant change, the monitoring should be strengthened. When the resistive current is increased by 1 time, the power failure should be checked.

The ambient temperature, relative humidity, and operating voltage at the time of measurement should be recorded. The measurement should be carried out when the surface of the porcelain sleeve is dry, and attention should be paid to the influence of phase interference.

1) Power plant and substation lightning arresters before the annual thunderstorm season

2) When necessary

Self-regulation

Use 2500V and above megger

1) Power plant and substation lightning arresters before the annual thunderstorm season

2) When necessary

Test 3-5 times should be normal action, the counter indication should be adjusted to "0" after the test