Electrical contractors no longer need to pull extra cable to meet the NEC's requirement for AFCI circuits in bedrooms. Southwire's Romex NM-B four-conductor non-metallic cable simplifies two-circuit wiring and reduces installation costs.
“Over the years, local codes have been developed in certain areas of the country that require separate circuits for bedrooms,” says David Mercier, technical director for Southwire's electrical division. “Our product allows the contractor to run back-to-back bedroom circuits while simplifying installation.”
The cable's second neutral can be reidentified, making it suitable for multi-circuit applications, such as three-function bathroom fans. The cable has also been used for whirlpool baths, ceiling and fan lights, and kitchen disposals and dishwashers. The NEC requires bedrooms to be equipped with AFCI breakers to protect a home against fire damage caused by faults in the electrical system. Southwire introduced the Type NM-B 2/2 cable to help contractors comply with the Code without changing their wiring practices.
“We had a distributor come to us on behalf of a contractor stating that with the new AFCI requirements he could no longer share a neutral on a three-conductor cable,” Mercier says. “He still wanted to make one cable pull to a bedroom rather than two, so we came up with a solution.”
After determining that the contractor's problem wasn't an isolated case, Southwire began developing a new product. The company made slight modifications to its existing cable and launched the new product as Romex Extra Circuit in May 2002. The manufacturer replaced the blue conductor in the standard four-conductor cable with a white neutral with a red stripe, making it possible to install the product in not only bedrooms, but bathrooms as well. Like many of Romex's other products, the cable is color-coded to ease identification and installation.
“We have received a very good response,” Mercier says. “Contractors who were originally using shared neutrals are excited about having a solution that does not require them to pull two cables. Plus those contractors who were not previously using shared neutrals have embraced this product due to the labor savings it provides.”
This non-metallic sheathed cable may be used for exposed and concealed work in normally dry locations no warmer than 90° C. NM-B cable is primarily used in residential wiring as branch circuits for outlets, switches, and other loads. The 600V rated cable may be run in air voids of masonry block or tile walls where such walls aren't subject to excessive moisture or dampness.
The cable meets or exceeds UL standards 83 and 719, Federal Specification A-A-59544, and the requirements of the NEC.
It's manufactured as 2-, 3-, or 4-conductor cable with a ground wire. Copper conductors are soft copper. Stranded conductors are arrow-straight. Conductor installation is 90° C rated polyvinyl chloride (PVC), nylon jacketed. The cable jacket is color-coded for size identification: 14 AWG — White, 12 AWG — Yellow, 10 AWG — Orange, and 8 AWG and 6 AWG — Black.