Gas Insulated Switchgear
Gas Insulated Switchgear (GIS) offers high reliability, safety, and maintenance-free features in a much smaller space, compared with conventional switchgear.
○The live parts are sealed in metal enclosures filled with pure SF6 gas. Thus, it is protected from contamination by smoke,
chemical fumes, dust or salt-laden spray or as ingress of small animals. This protection prevents the inside components
from oxidation and rust caused by oxygen and moisture.
○A medium voltage GIS can be installed into a space about half that required for a conventional type air-insulated metal-clad
○All the live parts are fully enclosed in grounded metal enclosures. Thus, there is no danger of an electric shock. SF6 is an
inert, non-flammable, non-toxic, and odorless gas used as an insulation and arc extinguishing medium. Therefore, it is safe
for personnel and there is no fire hazard.
‧Reduced maintenance costs
○Since the live parts are fully enclosed in an oxygen-free and moisture-free environment, there is no aging decay. This leads
to a reduction in labor costs for maintenance and inspection.
‧Short installation time
○A GIS of about four panels can be transported fully constructed. The GIS can be energized by connecting external power
cables to the pre-fabricated plug-in type terminals. Thus, shortening installation time.