When the increased nominal breaking current and the nominal voltage, the device switches should be upgraded, as well as to find the arc environment that has high electrical resistance and arcing abilities.Under surveillance were freon, sulfur hexafluoride and carbon tetrachloride.As a result, due to increased electrical resistance and good arc suppression characteristics came to the fore sulfur hexafluoride SF6. This gas has acquired the name of electrical or gas sulfur hexafluoride. Elegaz represents an electronegative gas, whose molecules capture electrons. In this connection it produced heavy, slow moving ions slowly increased electric field. All this makes it possible to operate insulating gas with high dielectric strength. Since different chemical inertness hexafluoride (up to 800 ° C), allowed to increase the temperature of the copper contacts 75 to 90 ° C. This current load was increased machine. Elegaz is non-combustible and fireproof material. His excellent performance made it possible to use it in many ways:
- high-voltage switches,
- power transformers,
- high voltage cables
- sealed complete switchgear.
Elegaz has its drawbacks: the significant increase in the temperature of a substance changes from a gas to a liquid state. In electrical devices use high-sulfur hexafluoride purification from impurities.