The GCBs will be delivered to the Xiluodu, Xiangjiaba, Jinping I&II, and Guandi hydropower projects.

Using SF6 as insulating and arc-extinguishing media, the GCBs are capable of cutting off a short circuit current of up to 210 kAs, and they can be deployed in generating units with a rated power level of up to 1500MW to withstand any fault currents, the company said.

The Xiluodu and Xiangjiaba plants, built and operated by the China Three Gorges Corporation, are located in the Jinshajiang River Basin, upstream of the Yangtze River, on the border between Yunnan and Sichuan provinces.

When they begin operations in 2015, the 12600MW Xiluodu plant will generate 64 billion kWh of electricity per year, while the 6400MW Xiangjiaba plant will generate 30.7 billion kWh.

Jinping I&II and Guandi plants, located in Yalongjiang River Basin, are being developed by Ertan Hydropower Development Company.

The Jinping I&II plants, with a total capacity of 8700MW, will generate 42 billion kWh of electricity when construction is completed in 2014.

The 2400MW Guandi plant, a complementary project for the Jiping I&II plants, will generate 11.8 billion kWh of electricity per year starting in 2013.