As the first Ultra High Voltage outdoor GCB, an Indian MNC CG has designed and developed the 800 KV versions through its own R and D efforts in the year 2009. The development is done to serve the growing demands of Indian Grid network for transmission of huge power added through 11th and 12th plans of the Ministry of Power, Government of India. These breakers are designed to clear a fault current of 50 kA. These GCBs are of Live Tank Design with spring-pneumatic mechanism. Closing is through spring and opening through air pneumatic pressure. The breaker has four break interrupters and employs dual flow puffer action for current interruption. This ensures high operational reliability and safety of power transmission.
The GCBs are capable of clearing the severe rate of rise of recovery voltage due to short line faults and high recovery voltage peak due to out of phase switching. Small currents such as capacitor bank switching currents, transformer magnetising currents, cable or line charging current are interrupted smoothly without any re-strikes or re-ignition and over voltages are minimized.