B
I would like to consult you and ask your opinion about the failure, while in service, of a POWL-VAC circuit breaker protecting the main transformer (GSU). The specs are the following:
Type: 15PV1000-63 Vacuum Circuit Breaker
3-phase, 60 Hz, 15 kV, 3000 A Continuous
Rated Short Circuit Current Cap = 48 kA
Impulse Withstand Rating = 95 kV
Instruction Books: IB-60010, IB-60013
The phase "A" damage parts are burned sliding contacts (with erosion marks), burned VI lower contact block, burned strut kit, shiny molten metals deposited on the strut kit, burned yoke, burned bell crank, base of the vacuum bottle and movable stem are also burned, soot deposits on the porcelain shell, part of the lower primary disconnect near the lower wishbone insulator was also burned. Phase B and C were not damaged.
Other observations on the phase A are bent operating pin and silver whiskers growing on the surface of the lower contact block. What do you think is the cause of the severe overheating of the said parts? And what are your recommendations (solutions and interventions) to prevent similar incidents from happening in the future?
Type: 15PV1000-63 Vacuum Circuit Breaker
3-phase, 60 Hz, 15 kV, 3000 A Continuous
Rated Short Circuit Current Cap = 48 kA
Impulse Withstand Rating = 95 kV
Instruction Books: IB-60010, IB-60013
The phase "A" damage parts are burned sliding contacts (with erosion marks), burned VI lower contact block, burned strut kit, shiny molten metals deposited on the strut kit, burned yoke, burned bell crank, base of the vacuum bottle and movable stem are also burned, soot deposits on the porcelain shell, part of the lower primary disconnect near the lower wishbone insulator was also burned. Phase B and C were not damaged.
Other observations on the phase A are bent operating pin and silver whiskers growing on the surface of the lower contact block. What do you think is the cause of the severe overheating of the said parts? And what are your recommendations (solutions and interventions) to prevent similar incidents from happening in the future?