Type THHN / THWN-2 Cu-Clad Conductor

The Copperweld^® THHN Advantage

Copperweld THWN-2 is a welcome alternative for small circuits applications. Lightweight and flexible, it pulls easily through conduit over long runs and bends. Installed to NEC requirements in Articles 310 and 240, Copperweld THWN-2 offers more electrical efficiency than its alternatives, pointing to lower monthly utility costs, less voltage drop and smoother running appliances. Discouraging pilferage and theft, it offers thieves only a small fraction of the scrap value of single-metal copper THHN, offering value to builders and contractors alike.

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-83, UL-1581, ASTM B566-4

Conductors — Solid or stranded annealed bimetallic conductor meeting ASTM B566 with an 8000-series aluminum core.

Conductor Insulation — Color-coded Polyvinyl Chloride (PVC) compound meeting the required thickness of Type THHN/THWN-2 with a heat-stabilized Nylon jacket rated for 90°C in dry locations.

Copperweld^® THHN/THWN-2 building wire is for general purpose applications defined by the NEC. It is allowed for new construction or rewiring for 600-volt applications and is appropriate for use in wet or dry locations in temperatures not to exceed 90˚C. For applications requiring Type MTW, the conductor is appropriate for use in dry locations at 90°C, or not to exceed 60°C in wet locations or where exposed to oils or coolants. In ducts or on trays for residential, commercial and industrial applications in fixed locations, in dry and damp locations.

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 THHN/THWN-2 conductors are referenced by Article 310 of the National Electrical Code for use in general wiring. OSHA safety listed: UL E510284.

Wiring Methods: Per section 310.3(B) and Table 310.4(A) of the National Electrical Code referencing Conductor Materials and Applications & Insulations Rated for 600 Volts, THHN/THWN-2 conductors are primarily used in conduit and cable trays and may also be used for services, feeders and branch circuits in commercial or industrial applications as specified in the National Electrical Code. THHN applications are suitable for use in dry locations only at temperatures not to exceed 90°C. THWN-2 applications are suitable for use in either wet or dry applications, with temperatures that do not exceed 75°C.

Copperweld THHN/THWN-2 is 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 below the cap to ensure safe electrical contact. Do not exceed the number of wires per the manufacturer’s instructions. Do not over-torque or under-torque. When terminating to panel lugs, circuit breaker terminals and wiring devices, torque to 12 to 14 lbf-in. Ensure secure connection while limiting wire deformation. Copperweld^® THHN/THWN-2 is made with ASTM B-566 Copper-Clad Aluminum copper bimetal, which carries its own component listing, RU DVVU2. Per UL Guide Information RTRT and WJQR, Copperweld^® NM-B can terminate with any wiring device (receptacle or switch) rated copper-only or CO/ALR. Copperweld^® THHN/THWN-2 satisfies Article 110.14 Electrical Connections as being SAFE for termination with ALL Copper-Only, Cu/AL or CO/ALR terminal connectors (Push-In, Crimp and Twist-On Types) and equipment. Copperweld^® THHN/THWN-2 may be pigtailed to single-metal copper wire in dry, damp and wet locations; however, code-compliant termination methods must be applied for each location. Listed connection equipment is required for damp and wet locations for all conductor material types, where oxide inhibitor must be applied. Copperweld^® THHN/THWN-2 should not be terminated with single-metal Aluminum wire without the application of an oxide inhibitor along with a terminal or connector specifically listed for the intermixing of dissimilar metals. Copperweld^® ASTM B-566 Copper-Clad Aluminum wire is not dissimilar to copper, brass or zinc-plated steel, and can be terminated with those metals without oxide inhibitors in dry locations only.