The breakdown voltage of sulfur hexafluoride is not only related to the pressure, but also related to the surface finish and cleanliness of the electrode. The cleaner and cleaner the electrode surface, the higher the breakdown voltage.

At the same pressure, the breakdown voltage of sulfur hexafluoride increases with the increase of the contact spacing, but it is not a linear relationship, but a little saturated meaning, and the more saturated the pressure is, the more serious it is; Therefore, in practice, we cannot increase the contact spacing to strengthen the insulation.

In addition, the breakdown voltage of sulfur hexafluoride also depends on the geometry and contact area of the electrode. If the electrode shape makes the electric field more uniform, its breakdown voltage will be higher. It should be noted here that, unlike the vacuum switch, the electrode material has no significant influence on the breakdown electrode of sulfur hexafluoride.

Sulfur hexafluoride are better insulation, because of the sulfur hexafluoride is electronegative, means that sulfur hexafluoride molecules can free electrons in the gas adsorption, and become negative ions, the quality of this negative ions is far greater than the quality of the free electrons, so the speed is greatly reduced, in addition, the number of free electrons in the clearance decreases, it will be difficult to form a breakdown channels. So its insulation performance is better. In addition, this electronegativity is also very advantageous at high temperature, that is, at the time of arc extinguishing.