Electrical Fires
Problems with fixed wiring
Electrical Fires
Tool Chest
Fixed wiring is the permanent wiring in the walls of a structure that connects things like wall sockets and light fixtures to a power source.
Renovations—especially the do-it-yourself kind—are a leading cause of electrical fires. Sometimes it's the tools themselves that cause them, thanks to frayed cords or not using extension cords appropriately.
However, most electrical fires are caused by problems with fixed wiring. Often, it's because the renovation adds an additional burden to existing electrical systems, and they can't handle it.
Goings-On Behind the Walls
Because electrical wiring is usually hidden inside walls, it's easy to not give it much thought. This oversight can and does lead to problems. According to the National Fire Protection Association, nearly 40,000 housefires and 350 deaths in the United States every year are caused by faulty home wiring and other electrical equipment such as plugs, lighting, and extension cords.
In the Nick of Time
If you're doing a remodeling that requires new wiring, get a permit before you start and have it approved by a qualified electrical contractor. If your municipality doesn't require these inspections (most do, however) or you can't find a qualified inspector, call your local fire department or building department for help.
It's especially a problem if you live in an older home, as the wiring in older homes wasn't designed to handle the higher demand that newer appliances place on it. Although it's true that today's appliances are more energy efficient than they were in the past, they're also bigger and we use more of them.
Problems like the following could very well be lurking behind your walls and in your ceilings:
Burned wire insulation in ceiling lights, typically caused by using bulbs with higher wattage than old fixtures can handle.
Frayed insulation around lights. Using improperly sized bulbs causes this, too.
Damaged insulation around fixed wiring. This happens over time from wires rubbing together. Nicks in the insulation or overloaded circuits are other culprits. Wires get hot, and the heat buildup causes insulation to crack or fray.
Tool Chest
Arcing takes place when an electrical current jumps through a tiny gap of air.
All of the above can cause a nasty little phenomenon called arcing, which is pretty much what the name implies: electrical current jumping between two things. Here, the current leaps through the air between the ends of broken wires or at loose receptacle connections. The energy from the current heats up the surrounding area, causing you guessed it, a fire. If there's not much oxygen to feed it, it can smolder for hours before bursting into flames.
Devices called arc fault circuit interrupters (AFCIs), which are installed in circuit-breaker panels, detect arcs that are so subtle that they typically don't trip circuit breakers. They're not a substitute for good wiring, but they do offer a measure of protection for older or damaged wiring. If you're in an older home, consider having them installed. If your home was built after January 1, 2002, circuit interrupters were installed on all bedroom circuits, as per national electrical code requirements.
Alternative wiring, signs of trouble
Alternative Wiring Products
A Fine Mess
Electrical inspections typically aren't required when houses are sold, which means that worn-out wiring and "fixes" made by previous owners often aren't discovered until they cause problems.
During the mid-1960s to the mid-1970s, many homebuilders substituted less-expensive aluminum wiring for copper wiring in branch circuits-the circuits that feed electricity from a house's main circuit panel to its rooms. While aluminum was believed to be a safe substitute, it didn't prove to be over time, as the wiring oxidized and loosened at connections, resulting in arcs and overheating.
Many home electrical systems have been upgraded to safer copper wiring, thanks to a public information campaign conducted by the Consumer Product Safety Commission. However, experts believe that thousands of homes from this era have yet to be repaired and are still at risk.
Aluminum wiring is permitted, and is commonly used, for main incoming lines and any dedicated 220-volt loads such as stoves or ovens. Houses that have aluminum branch wiring can be made safer by replacing outlets and switches with aluminum-rated outlets and switches-a cheaper solution than rewiring with copper wire.
Signs of Problems
How do you know if your house's electrical wires are a potential fire risk? The following is a list of warning signs that you shouldn't ignore:
Flickering lights
Outlets that feel hot to the touch
Circuit breakers that repeatedly trip
If any of this is going on in your home, disconnect all appliances that are plugged into the overworked circuits and call a licensed electrician right away.
Other Causes of Electrical Fires
Animals like squirrels and other rodents are a leading cause of fires with unknown origins. Typically, it's their lifelong need to chew that causes the problems, but their nests can also be fire hazards.
Lightning strikes cause almost 20,000 fires every year. Most happen outside, but they can and do happen indoors, too, thanks to the natural attraction between the electrical currents in wiring and lightning bolts.