Inspection Detail

Inspection: 315526434 - International Line Builders, Inc.

Inspection Information - Office: Santa Ana District Office

Investigation Summary

On October 26, 2011, Employee #1 was the foreman of a four-person crew working for a company that built and maintained electric power distribution systems. The crew was replacing an existing unfused 225 KVA pad mount transformer (PMT) with a new fused 300 KVA PMT. The existing overhead feed was to be replaced with a new underground feed for the new transformer. After crew members isolated the existing PMT from the overhead service, they realized that they neglected to identify the phase sequence. A rotation meter was to be used to identify the phase sequence, which required them to reconnect the overhead service. Temporary jumpers were used to reconnect the power from the overhead lines to the pothead feeding the PMT. Employee #1 was located directly in front of the PMT with an 8-ft hot stick attached to the PMT switch to reenergize its secondary side. A coworker was standing on the back side of the PMT, holding the rotation meter that was connected with long leads to the front of the PMT. When Employee #1 turned on the PMT switch with the hot stick, there was no reading on the rotation meter. Employee #1 turned off the PMT switch and asked the coworker to hold down the button on the meter to enable the reading. When Employee #1 again turned the on the PMT switch with the hot stick, the PMT exploded. Hot oil spewed out and ignited. Employee #1 was hospitalized with first- and second-degree burns to his face, hands, and upper back. The coworker sustained minor burns to his face.

Keywords: BURN, ELECTRICAL TESTING, ELECTRICIAN, FIRE, LUBRICATING FLUID, TEST EQUIPMENT, EXPLOSION, FACE, TRANSFORMER, HAND