The cause for one accident in Xichang power grid is analyzed

and it shows that misoperation of protective gas neutral point is the result of the unsuitable setting of neutral point protective gap of transformer.It proposes that when setting the protective gap of the neutral point of transformer

it is not suitable to set one certain value

it is necessary to consider the actual height above sea level and the impact of dirtiness on the operating environment

and then the setting needs to be corrected.