Typical Faults Analysis for 550 kV Circuit Breaker

Two faults of SF6circuit breaker porcelain bushing explosion and arc reignition in interrupting course are analyzed. According to the fault records, disassembly checks and material inspections, two faults are respectively due to improper proportion of stuffing in nozzle and fracture of turn-arm of insulated pull rod. The effect of nozzle material on interrupting capability of the SF6circuit breaker is analyzed.Conclusions are drawn that: ①Power industry should pay more attention to quality control and supervision of circuit breaker core components; ② Live-line detection technology, fault record analysis and familial defect diagnosis are important methods for diagnosing these kinds of latent faults in operating equipment.