Inspection Detail

Inspection: 302933965 - Duke Energy (Buck Steam Station)

Inspection Information - Office: Nc Department Of Labor - Winston-Salem

Investigation Summary

Two utility employees were cleaning the cooling condensers on four step-up transformers. The two employees had cleaned the condensers on two of the transformers the day before, with one transformer energized and the other deenergized. They met at the substation to resume the operation and decided to switch jobs. The employee who had been working on the ground the day before was going to do the cleaning. The employees cleaned the third transformer, which was deenergized. When they finished, they moved to the last transformer, which remained energized. The employees put a 7.3-meter-long extension ladder against the side of the transformer and pulled a 38-millimeter-diameter fire-type hose into position to clean the cooling condenser. They turned off the pumps and fans, and the employee who was to do the cleaning climbed the ladder. He got into position to direct a stream of water through a plastic, adjustable nozzle. (The water was pumped from a river.) Facing the transformer, he directed the water toward the cooling condenser, located to his left, starting at the top, which was above his head. The other employee was on the ground in the diked area near the bottom of the ladder. The employee on the ground began to get wet, so he decided to walk about 6 meters away so he could watch the first employee and help direct him. Before the employee on the ground turned around, he heard an explosion. Electric arcing was occurring above the employee on the ladder. An electrical fault had occurred in the transformer, blowing off the cover and causing a high-voltage bushing to fail. Burning oil erupted from the damaged cover and bushing onto the employee on the ladder. The employee on the ground used the damaged hose to direct water onto his coworker, who had been engulfed in flame. The injured employee died of his burns about 2 hours after the accident.

Keywords: BURN, ELECTRIC ARC, ELECTRICAL, POWER LINE WORKER, HYDRAULIC FLUID, E PTD, ELEC UTILITY WORK, ELECTRICAL FAULT, TRANSFORMER, WATER