Littleton First Rescue in Littleton, Colorado has responded to multiple house fires in recent months. The fires were caused by electrical arcing at the main electrical service panel on the home’s exterior.
Electrical arcing is an electric current, often strong, brief, and luminous, in which electrons jump across a gap. Electric arcs across specially designed electrodes can produce very high heats and bright light. Unwanted arcs in electrical circuits can cause fires.
The arcing that caused these house fires was a result of the main electrical service line being pulled loose from the breaker panel due to the ground settling around the home’s foundation. This hazard is found where the main electrical lines are run underground onto the property, not where the lines are run overhead from power poles.
In a typical situation, the main electrical lines are run underground to the home foundation and then up to the breaker panel. When the ground around the foundation settles over time, a condition may occur where the conduit, and the main electrical line within it, is pulled down from the breaker panel. This stress can loosen the connection of the main electrical line to the breaker panel and the cause electricity to attempt to arc across the gap. This arcing eventually ignites the exterior of the house. Because the fire starts on the exterior; an interior smoke alarm system will not activate until the fire spreads to the interior of the home.
Homeowners with underground electrical service should have their breaker panel inspected regularly. If a gap is found or the conduit connection is broken, call your local electrical utility department and ask for inspection and repair.
For more information on electrical fire safety click:
http://www.usfa.fema.gov/citizens/home_fire_prev/electrical.shtm