Delplace, Michael and Vos, Eddie. Electric Short Circuits Help the Investigator Determine Where the Fire Started. Fire Technology. Vol. 19, No. 3. August 1983. National Fire Protection Association.

Abstract: This article explains procedures investigators may follow to determine if the fire was of electrical origin. The inspection of short circuits can reveal important information about the fire. Damage to wires and arcs can help investigators trace the steps of the fire.

Copper wiring can survive a fire with little or no damage. Its melting point is 1,981 degrees F. When it is heated it releases an oxide that can be removed with hydrochloric acid for examination. This procedure will not destroy the evidence that lay beneath the oxides. Aluminum wires have a much lower melting point and are usually destroyed by fires, leaving no evidence behind.

This article lists indicators of damage caused by electrical arcs, heating or alloying, and mechanical damage. The article also explains how to trace the point of origin by examining short circuits and electrical arcing. The point of origin must reinforce other observations found at the fire scene such as burn patterns and witness accounts. Once the point of origin has been determined, a source of heat and combustible materials should be found near the area of origin.

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