From Dormancy to Operation: Successful Restoration, Installation and Commissioning of a 420kV Gas Insulated Switchgear (GIS) After Prolonged and Adverse Storage

This paper presents a detailed case study on the successful restoration, installation, and commissioning of a 420kV Gas-Insulated Switchgear (GIS) system at a hydroelectric power project in India, following an extended period of dormancy. The GIS equipment, originally delivered during the early stages of the project, remained uninstalled for over 12 years due to a prolonged construction halt caused by local agitation. Despite the significant time lapse and adverse storage conditions, the equipment was eventually revived and commissioned, offering a unique example in transmission and distribution (T&D) infrastructure at global level.