Inspection Detail

Inspection: 310194956 - Western Utilities Transformer Service

Inspection Information - Office: Van Nuys District Office

Investigation Summary

At approximately 10:00 a.m. on October 26, 2006, Employee #1, a lineman supervisor with 22 years of experience working for a high-voltage electrical contractor, was evaluating a job to determine the work needed to complete it. His employer had been contracted to install a 12,000-volt power line at Vandenberg Air Force Base. The project had been started by and then abandoned by a previous contractor. Power poles, wires, and a transformer had already been installed, none of which were energized. The project began at an existing electrical substation, in an energized 12,000-volt electrical panel. The section of the electrical panel involved in the project was not energized. However, the energized portion of the panel was approximately 2 feet below it, and no insulating barriers separated the two sections. Employee #1 wanted to examine the connections inside the electrical panel to determine the amount and type of work that still needed to be done. This included checking the integrity of the connections, using a high potential (HI-POT) test. A coworker apparently working at the substation advised Employee #1 and the company superintendent that the panel was still energized and cautioned them not to open it. The coworker also told them that the panel would be deenergized in about a week and that they should open the panel then. Employee #1 told the coworker that they had the necessary protective equipment, they knew what they were doing, and they had permission to open the panel. The coworker acquiesced and returned to a desk in the substation. Employee #1, who was not wearing face, hand, or body personal protective equipment (PPE), removed the access cover to the panel line connections and began checking for voltage with a non-contact voltage "tick" tracer. He observed uninsulated concentric ground conductors leading from the project cables toward the area of the energized electrical bus. Just as he turned to his right to tell the company superintendent what he had seen, the panel exploded and an electrical flash fire occurred. The coworker later confirmed that he had heard the "tick" tracer indicating the presence of electricity and immediately heard two explosions in rapid succession. Employee #1 suffered third-degree burns to his hands and second-degree burns to his face and head, which resulted in complete hair loss. He was transported to Fresno Burn Center, where he was hospitalized for five days. Two months after the accident, Employee #1 was still unable to use his hands. The subsequent investigation concluded that Employee #1 and the company superintendent knew that high voltage was present in the panel but did not isolate the high voltage from their project area. It was also concluded that Employee #1 had not worn the face, hand, and body protective equipment required for work in an energized electrical panel. The employer was cited for a serious, accident-related violation.

Keywords: BURN, HEAD, PPE, CONSTRUCTION, LOCKOUT, ELECTRICAL FAULT, FACE, HAND