72 kV C-GIS composite insulation in SF6 gas

For further reduction in installation space, the authors have developed a second generation C-GIS (cubicle gas insulated switchgear) which makes use of a composite insulation of low pressure SF₆ gas and solid material. The new C-GIS has realized a reduction in installation space of about 50% from conventional C-GIS. The authors introduce a gas-solid composite insulation employed in the C-GIS, and a new technique that eliminates the need to recharge the insulation gas into the cubicle during the site erection, contributing to shortening the installation period while maintaining its reliability. An overview of the second generation C-GIS is given