Energized neutral effects on corrugated gas supply lines

Abstract

In the course of performing fire investigations, it is not uncommon to encounter a fire where the ignition source is identified as electrical in nature. Furthermore, we have all likely encountered a situation where the fire occurred as a result of the neutral circuit being energized (short circuited to line potential). This article will share what occurred during one particular instance where a home owner witnessed and photographed an energized neutral event. Fortunately, a fire did not occur, but easily could have. The home owner photographed the gas appliance connector connected to a water heater that was glowing red hot during the event. It is the intent of this article to share the particulars of this case and explore the effects of an energized neutral circuit as it relates to current flow in a gas appliance connector. The energized neutral circuit was witnessed and documented by the home owner. The glowing gas appliance connector was a real event, not theoretical or staged. The glowing gas appliance connector did not result in a fire; however, it did raise questions regarding the current carrying capability of the gas appliance connector and what level of surface temperatures resulted from the current flow through the short section of gas line. The energized gas appliance connector was duplicated in the lab. The external surface temperature of the gas appliance connector was measured at various current levels and documented.