The circuit breakers, to be installed in five 750kV transmission substations around the country, will replace outdated air blast-type circuit breakers that have been in operation for nearly four decades.
The replacement of the circuit breakers will be done in four phases, starting in 2011 and ending in 2014.
The 800kV SF6 circuit breaker of ABB features a single operating mechanism per pole, replacing the two found in conventional 800kV breakers.
ABB claims that this provides reduced initial costs, greater reliability and considerable reductions in maintenance costs.
The company will also supply control cabinets with bay control devices for the circuit breakers, along with an on-line condition monitoring system built on its substation automation technology.
