Prevention of fires in your home is one of the most important aspects of design and construction. National statistics show that a regular source of fire stems from faulty wiring inside the walls of a home. Consider for a moment all the nails teenagers, parents, or tenants might pound into walls for hanging pictures, installing shelves or cabinets, and hanging hooks, then multiply that by the number of families moving in and out of a dwelling over time. It is likely that the wires in a wall may get pierced causing the bare copper conductors to be exposed. Under that condition, unintended electrical arcing can occur. An electrical arc can reach 10,000 degrees and is capable of igniting materials such as insulation or wooden wall members.
To prevent the occurrence of unintended arcing inside a home, a device called an arc-fault circuit-interrupter (AFCI) needs to be installed in a home’s electrical panel. In the recent past, building standards only required AFCIs on electrical circuits serving bedrooms. However, in January 2008, the national standard was expanded to require AFCIs on electrical circuits serving: family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, or similar rooms or areas. Additionally, the revised standard requires that AFCIs also be a “combination type”, which means the device must also provide arc-fault protection for devices wired in series down to 5 amperes. This series arc detection is beneficial to detect lower level arcing in both branch circuits and power supply cords. While the new requirement impacts new construction, for the safety of your family, it is a wise investment to install AFCIs in your home’s existing electrical system.
For more information and technical details you may also consult the National Fire Prevention Association or NFPA. The organization maintains and publishes 300 separate codes and standards. Code number 70 is called the National Electric Code or simply the NEC. (Note: the NEC is not a separate organization or group.) The specific section dealing with AFCI’s is NFPA-70 NEC 2008 Capter 2, Article 10, Section 12, or in shortened tech-speak: NEC 210.12)
Greg Bertaux PE, CIEC.
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