Gas Insulated Switchgear (GIS)

A Gas Insulated Switchgear (GIS) is an advanced type of switchgear where electrical components such as circuit breakers, disconnectors, earthing switches, busbars, and current transformers are enclosed inside a sealed metal enclosure filled with insulating gas, typically SF₆ (Sulfur Hexafluoride) or modern eco-friendly alternatives.

GIS provides excellent insulation performance, high reliability, and requires significantly less installation space compared to conventional air-insulated switchgear (AIS). Due to its compact design and resistance to environmental conditions, GIS is widely used in urban substations, power plants, industrial facilities, airports, renewable energy projects, and high-voltage transmission networks.

Key Features

• Compact space-saving design
• High dielectric insulation performance
• Metal-enclosed construction for safety
• Excellent reliability and low maintenance
• Protection against dust, moisture, and pollution
• High short-circuit withstand capability
• Suitable for indoor and outdoor installations
• Long service life
• Remote monitoring and control capability
• Reduced substation footprint
• High operational safety

Main Components

• Gas-insulated busbars
• Circuit breakers
• Disconnect switches
• Earthing switches
• Current Transformers (CT)
• Voltage Transformers (VT)
• Surge Arresters
• Cable Termination Units
• Control and Protection Panels
• Gas Monitoring System

Common Applications

• High Voltage Substations
• Power Generation Plants
• Transmission Networks
• Industrial Power Systems
• Renewable Energy Plants
• Metro Rail Systems
• Airports
• Oil & Gas Facilities
• Data Centers
• Urban Electrical Substations

Common Types

• Medium Voltage GIS (MV GIS)
• High Voltage GIS (HV GIS)
• Extra High Voltage GIS (EHV GIS)
• Hybrid GIS
• Indoor GIS
• Outdoor GIS

Typical Specifications

• Voltage Range: 11 kV – 800 kV+
• Rated Current: 630 A – 5000 A+
• Short Circuit Rating: 16 kA – 80 kA+
• Insulation Medium: SF₆ gas / Eco-efficient gas alternatives
• Protection Class: Metal enclosed, IP-rated designs

Popular Brands

• Siemens Energy
• ABB
• Hitachi Energy
• Schneider Electric
• GE Grid Solutions
• Mitsubishi Electric
• Toshiba Energy Systems
• Hyundai Electric
• Eaton
• Fuji Electric