Stay Ahead Of The Spark
Understanding And Preventing Electrical Fires
Published: August 2014
By Tom O'Connor
The leading cause of residential fires in the United States each year - and the second leading cause of nonresidential fires - is electrical failure and malfunction. Electrical fires have caused hundreds of deaths, thousands of injuries and more than a billion dollars in property damage over the last several years alone. Fortunately, being able to understand the causes, and having the ability to identify the hazards that lead to these fires, can go a long way in preventing them.
As an electrician or lineman, it is important to be aware that the most common causes of electrical fire are short circuits in wiring or cables and overloaded conductors, cables or equipment. They also include poor or loose connections, built-up static electricity, use of inferior-grade materials or equipment, frequent blowing of fuses, and the presence of flammable materials near electrical heat sources.
As a result, many electrical fires can be avoided by renewing aged wiring, using good quality wires and cables, keeping fuse boards away from combustible materials, using fuses of adequate capacity and steering clear of joints when wiring. Soldering and proper mechanical joints can be made if this cannot be avoided.
Other everyday fire-avoidance tactics include replacing any damaged or loose wiring/electrical cords and keeping extension cords away from doorways, walkways or under carpets. If an extension cord is necessary, an additional circuit or outlet must be installed to avoid using them so frequently. Making customers aware of the dangers of extension-¬cord use can convince them to add circuits or outlets.
It is also imperative to follow any manufacturer's instructions and warnings when plugging in an appliance or piece of equipment. This will help prevent overloading an outlet. Also, only one high-voltage appliance or piece of equipment should ever be plugged in to an outlet, or run off of one circuit, at a time.
Ensure you follow NEC requirements anytime outlets are installed in kitchens, bathrooms, laundry areas, basements, outdoor areas or anywhere it may come in contact with water. Primarily, they should be equipped with ground-fault circuit interrupters (GFCIs). The Occupational Safety and Health Administration (OSHA) requires their use for all construction activities.
OSHA defines a GFCI as "a fast-acting circuit breaker designed to shut off electric power in the event of a ground-fault within as little as one-fortieth of a second. It works by comparing the amount of current going to and returning from equipment along the circuit conductors. When the amount going differs from the amount returning by approximately 5 milliamperes, the GFCI interrupts the current."
Ensure GFCI devices meet these expectations. Select tamper-resistant outlets where children or animals can easily access them.
The National Fire Protection Association's (NFPA) Online Guide for Home Safety advises homeowners that outlets or switches that feel warm, fuses that blow frequently, circuits that trip, and lights that flicker or dim are cause for concern. Ensure you pass this information on to customers. Let them know these are telltale signs that an electrical fire could be imminent. Instruct them to discontinue use and contact you or another qualified electrician to address the problem. This will empower them to take action.
The NFPA also recommends, "placing fixtures on level surfaces, away from things that can burn, and to use lamps that match the fixture's recommended wattage." The organization said that 63 percent of all home-structure fires between 2007 and 2011 involve electrical distribution to lighting equipment, lamps and lighting fixtures.
According to the United States Fire Administration's Statistical Report: Electrical and Appliance Fires, (2009–2011), "In 79 percent of residential building electrical fires, the fire spread beyond the object where the fire started." Therefore, it is important to know how to confront an electrical fire. The first course of action is to call 911 and alert colleagues or other building occupants of the danger. If the fire is small enough and you have been trained and are equipped to do so, you may attempt to extinguish the fire.
However, electrical fires are extremely dangerous. Not only can they cause burns, but they also can lead to electrical shock. Therefore, these types of fires must be extinguished properly. Class C fire extinguishers are designed for use on fires caused by electrical equipment. The C classification means the extinguishing agent is nonconductive. Using water to attempt to contain or extinguish an electrical fire can result in the flames getting bigger or lead to electrocution.
Although electrical fires seem to be inevitable in some cases, following these prevention tactics, along with awareness of the hazards that cause them, will drastically reduce the chance that a fire will occur.
For more information, visit www.nfpa.org and www.osha.gov. Both organizations offer useful publications, standards, technical assistance programs and compliance tools.