Type NM-B
Cu-Clad Conductor
600 V | Premium Building Wire

The Copperweld® NM-B Advantage
Copperweld NM-B Cable is a welcome value to every stakeholder in the residential space. Installed to NEC requirements in Articles 310 and 240, Copperweld NM-B cable offers more electrical efficiency than its alternatives, pointing to lower monthly utility costs and smoother running appliances. Its light weight and flexibility create opportunities for labor savings for electrical contractors. Discouraging pilferage and theft, it offers thieves only a small fraction of the scrap value of single-metal copper NM-B cable, offering value to homebuilders and contractors alike. Copperweld NM-B cable can offer long-term cost stability to the supply chain.
Product Overview
Cu-Clad Aluminum (CCA) Conductor — Drawn from a copper-clad aluminum rod, with the copper metallurgically bonded to an AA 8000 series aluminum core, where oxygen-free copper forms a minimum of 10 percent of the cross-sectional area of a solid conductor or each strand of a stranded conductor.
Application Standards — UL (UL-83, UL-719, UL-1581, UL-2556); NFPA 70 (NEC®) Article 334; ASTM-B-566; NEMA RV 2-2011
Conductors — For wire sizes 12-10, solid annealed THHN Copper-Clad Aluminum with solid Copper Clad Aluminum ground. For 8 AWG sizes and larger, stranded annealed THHN Copper-Clad Aluminum with solid Copper-Clad Aluminum ground.
Conductor Insulation — Color-coded Polyvinyl Chloride (PVC) compound meeting the required thickness of Type THHN or THWN-2 with a heat-stabilized Nylon jacket rated for 90°C in dry locations.
Grounding Conductor — For NM-B 12-10 AWG sizes: ground will be 12-10 AWG, solid, annealed conductor. For NM-B 8 AWG sizes and larger: ground will be 8 AWG, solid, annealed.
NM-B Jacket — Made with 30-mil flame retardant and moisture resistant PVC to safety listing standards. Colors according to industry norms and specific application.
Theft Deterrent
Metallugically bonded conductor results in lower scrap value, reducing theft.
Energy Efficient
Better energy efficiency than standard residential branch circuit wiring.
Cost Stable
Reduced exposure to commodity fluctuation improves your bottom line.
Identification, Applications and Usage
Copperweld® Copper-Clad Aluminum Type NM-B (non-metallic sheathed cable) is referenced by Article 334 of the National Electrical Code. OSHA safety listed: UL E492024. ETL listing: 5021266.
Wiring Methods: Per Article 334 of the NEC, Copperweld® Type NM-B shall not be used in wet or damp locations where an electrolyte might be present. It may only be used in dry locations for indoor wiring. Copperweld® NM-B cable should be sized per NEC ampacity table 310.16 using the 60°C column. It may be used as the primary electrical conductor for the residential branch circuit system, providing service for outlets, switches and 240 Volt appliance loads. It cannot be used as a service entry cable, nor can it be buried. Copperweld NM-B must be protected from physical damage per Article 300.4 of the NEC. It must not be installed in locations exposed to corrosive fumes or vapors. Per Article 590, Copperweld® NM-B can be used in temporary installations as feeders and branch circuits for power and lighting. Type NM-B is rated 600-volt for both exposed and concealed work in dry locations, as defined by the National Electrical Code.
Identified for use with wiring devices, splice connectors and equipment terminals rated for Cu, Cu/Al and CO/ALR. When terminating with twist-on splice connectors, pre-twisting is not recommended. Torque until the wires are tight under the cap and visibly twisted together two times outside of the cap to ensure electrical contact. Do not over-torque or under-torque. Ensure secure connection limiting wire deformation. Copperweld® NM-B is made with ASTM B-566 Copper-Clad Aluminum bare wire, which carries its own component listing, RU DVVU2. Copperweld NM-B conductors are suitable to terminate on 15 and 20 ampere rated wiring devices (receptacles and snap switches) marked ‘copper only’ or ‘CO/ALR’. For termination on devices rated 30 amperes or greater, the termination must be marked ‘CU/AL’ or equivalent. Please consult UL Product IQ guide information RTRT and WJQR if further confirmation is required. Copperweld® NM-B CCA conductor satisfies Article 110.14 Electrical Connections as being a similar metal to copper for the purposes of electrical connections. Copperweld® NM-B may be pigtailed to single-metal copper wire in dry locations. Copperweld® NM-B cable should not be terminated with single-metal aluminum wire without the application of an oxide inhibitor or a terminal or connector specifically listed for the intermixing of dissimilar conductor metals. Copperweld® ASTM B-566 Copper-Clad Aluminum wire is not dissimilar to copper, brass or zinc plated steel.
Code Compliant
NEC Compliant for 600 Volt residential branch circuit conductors since 1972.
Safety Tested
Listed by UL and ETL to NM-B Standard UL 719 for residential electrical wire.
Performance Proven
50 years of safe residential use with standard circuit components.
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