Electrical Case Study

Case Synopsis: A fire broke out in the electrical room of a dialysis treatment center. A roofing company installed a new roof on the building just six months prior to the fire. An expert was retained, on behalf of the insurer of the roofing company, to determine if water intrusion caused the fire.

Expert Analysis: An inspection of the equipment in the electrical room showed that the fire was caused by the failure of a 400A, 3-pole, 480V molded case circuit breaker. The interphase barriers had deteriorated and caused a phase-to-phase and subsequently a phase-to-ground short circuit. The arc caused nearby combustibles to ignite. Inspection of the damaged distribution panel and other panels in the electrical room showed no signs of rust or water intrusion. Inspection of the ceiling directly above the electrical distribution panel showed no signs of leaks. Inspection of the new rubber roof above the electrical room showed that it was in pristine condition and that the roofing contractor had used good materials and that the quality of the installation showed good workmanship. The circuit breaker failed due to age and insulation breakdown and not because of water intrusion.

Result: The insurer dropped the case against the roofing contractor.