Inspection Detail

Inspection: 303393102 - Gpu Energy

Inspection Information - Office: Marlton Area Office

Investigation Summary

A utility worker was in an underground vault troubleshooting a lights-out call. He had removed a blown 100-amp fuse from an oil-filled cutout and replaced it with a 6-amp fuse in an attempt to energize the transformer in the vault. When he turned the switch to restore current to the 4,160-volt side of the transformer, the cutout exploded, causing an arc blast and igniting the oil in the cutout. The arc struck the employee in his head and upper torso. He died immediately from the severe burns he sustained. A forensic examination of the cutout determined that a small vent hole in the top of the fuse holder was blocked by carbon deposits that had built up from previous arcs. When the fuse holder was reinstalled in the cutout, the blocked vent allowed an air bubble to be created above the fuse. Then, when the cutout was brought online, a fault current tripped the fuse, creating an arc that was not quenched. The cutout was then destroyed, releasing the arc and the flaming oil.

Keywords: BURN, E GI V, ELECTRIC ARC, ELECTRICAL, POWER LINE WORKER, PPE, E PTD, TRANSFORMER VAULT, ELEC UTILITY WORK, ELECTRICAL FAULT