Do you know any of DC motor applications in Industries? Are you at home now? Or, are you in the office? If not, are you on the site? Anyway, there is
Gas insulated switchgear is a metal closed type switchgear that acts as an insulator between live parts and soil metal casing with sulfur hexafluoride (SF6) gas. High voltage equipment is housed in a gas tight container filled with a degassing gas called SF6.