Electrical fires: the most common ones at home

Electrical fires are fires involving potentially energized electrical equipment. This sort of fire may be caused by short-circuiting machinery or overloaded electrical cables. These fires can be a severe hazard to firefighters using water or other conductive agents: Electricity may be conducted from the fire, through water, to the firefighter’s body, and then earth. Electrical shocks  have caused many firefighter deaths.

A fire will occur in a place you can’t easily see. Waste heat generated by the electrical current can cause wiring hidden within a home’s walls to expand and contract, eventually loosening it. Once that wiring is loose, the electricity can arc, with a heat output reaching 1,500 to 1,800 degrees Fahrenheit. That’s more than enough to ignite wood or old insulation under normal circumstances, but winter weather is less humid than in the summer. Inside a house in the winter months, the relative humidity within the walls can drop to that of the average desert, turning studs– wooden wall supports — into kindling, easily ignited by an arcing current.

Here we arrive at one of the problems with electrical fires: By the time you see smoke coming out of your outlet, a fire has most likely already begun and is spreading out of sight within your walls and up to your attic. Even worse, electrical fires can be particularly tricky to put out. Since they involve electricity, using water to put out the fire can cause electrocution. Chemical powders can cause the fire to smolder then reignite. You should turn off your power (if it’s safe) and leave your house. Once electricity is shut off to the equipment involved, it will generally become an ordinary combustible fire. Then call the emergency number to report the fire.