1. Selection of main parameters: valve arresters should be selected according to the technical standards listed in the relevant requirements.
2. When using valve arrester for lightning overvoltage protection, in addition to rotating motors, choose arresters with different operating voltage ranges and different system software grounding methods.
3. The residual working pressure of the valve arrester under the standard charge and discharge current cannot exceed 71% of the lightning impulse full-wave withstand working voltage (BIL) of the electrical equipment under maintenance (other than rotating electrical machines).
4. The rated current of metal oxide arresters and carbon-carbon composite valve arresters should generally meet the following requirements:
(1) 110kV reasonable grounding protection is not less than 0.8Um.
(2) 3~10kV and 35kV, 66kV system software is not less than 1.1Um and UM; 3kV and above generator set system software maximum operating voltage is not less than 1.1 times.
(3) The rated current of the neutral point arrester is not less than 0.**Um and 0.58Um respectively; the maximum operating voltage of the 3~20kV generator set is not less than 0.** times.
5. When selecting non-void metal oxide arresters as lightning overvoltage protection equipment, the corresponding regulations should be met.
6. For the 110kV and 220kV transformers whose neutral point is classified as the insulating layer, if the isolating switch with poor synchronous performance is used, the metal oxide arrester should maintain the neutral point of the transformer.
7. Void-free metal oxide arresters are classified according to their standard charge and discharge currents.
8. The arrester with system software rated current of 35kV and above should be equipped with charging and discharging posture monitoring software.