IEEE Power & Energy Magazine - May/June 2018 - 97
figure 20. The Westinghouse 345-kV OCB at the Ohio
Valley Electric Corp. (From Westinghouse Descriptive Bulletin DB-33-254, July 1956.)
prevent voltage flashovers to the tank wall during the higher
63-ka current interruption.
the application of the oil breaker did require certain considerations by the utility engineering users, such the potential
of an oil fire in the event of failure. although this was a rare
event, its possibility influenced the location of the substations. as explained previously, the interruption of a fault can
be summarized as controlled explosions as the arc is extinguished within the interrupters. as fault current increased,
the magnitude of the resulting forces required design attention to tanks and foundations. energy-absorbing designs
internal to the tanks consisted of trapped air chambers and
submerged air bladders for shock absorbers; however, the
breaker stability during fault interruption still required specific sizing and hold-down bolting.
history shows that the production and installation of OCBs
met the needs of the electrical transmission systems into the
1980s. today, a breaker using sulfur hexafluoride gas is now
the one of choice to satisfy the continued demand of higher
voltages, increased currents, capacitance and reactor switching; however, thousands of OCBs remain in service.
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