Example OpEx Event Report -13.8 kV Bushing Failures

摘要

On Dec. 9 at 2300 hours, a transformer differential alarm was received and the Unit 3 generator tripped offline. Immediate investigation revealed failure of one of the C-phase standoff bushings in the 13.8-kV leads tunnel between the generator breaker and step-up transformer. Further investigation revealed rainwater intrusion through cracks in the concrete deck of the transformer yard. Calcium deposits were formed, copper grounding bars were oxidized, and other bushings and sections of the bus bar were wet.