Bare copper wire buyers in New York

Green insulation is not bare copper

This is the most common confusion on a grounding lot. A green conductor is an insulated conductor whose jacket happens to be green — usually THHN/THWN or XHHW-2. The green identifies it as an equipment grounding conductor under NEC 250.119, which reserves solid green, or green with one or more yellow stripes, for that purpose alone. No phase conductor and no neutral may be green.

The difference matters three ways. First, use: green insulated wire is a recognised equipment grounding conductor inside a raceway, and it is what an inspector expects to see pulled with feeder conductors. Bare copper serves a different set of roles — grounding electrode conductor to a rod or water pipe, bonding jumpers, ground rings — and in some installations the code requires an insulated conductor where bare would otherwise be acceptable, particularly in corrosive locations.

Second, handling: to use green insulated wire as bare copper, somebody has to strip it, and stripping 4 AWG or 250 kcmil by hand is slow, damaging work. Third, value: green insulated cable with an intact jacket and readable print should be sold as insulated building wire, on its own terms, not folded into a bare copper lot where it will be valued only for contained metal. Keep the two piles apart before anyone photographs them.

Where bare copper actually lands

Grounding electrode conductors connect the service or the source to earth. The electrode may be a driven rod, a metal water pipe, building steel, a concrete-encased electrode in the footing, or a buried ground ring, and NEC Table 250.66 sizes the conductor by the size of the service conductors. On a small service that can be 8 AWG copper; on a large service it climbs through 4, 2, 1/0 and beyond. That table is the reason a bare copper lot contains so much 6, 4, 2 and 1/0 in solid and 7-strand.

Equipment grounding conductors run alongside a circuit and provide the low-impedance fault path. Bonding jumpers tie metal parts that must sit at the same potential: water and gas piping, structural steel, cable tray, busbar enclosures, elevator rails and skid frames. In utility and industrial work the same material reappears as counterpoise and grid conductor around a substation, where 2/0, 250 kcmil and 500 kcmil soft-drawn stranded copper are buried in crushed stone and bonded to every structure.

Lightning protection, transit and telecom add smaller but very clean material: 2 AWG and 1/0 bare copper down conductors, ground ring conductor around antenna structures, and the heavy bonding conductor used in subway and rail traction grounding. All of it arrives on site as coils, and most of it leaves as coils when a project closes.

What decides what a coil is worth

Copper content sets the floor and condition sets the ceiling. Because the metal is exposed, bare copper is the easiest wire family in which to see whether a coil has been stored properly: bright salmon-colored copper with a clean surface has been indoors, and green verdigris with black oxide has not. Oxidised copper still contains the same metal, but it is no longer a conductor somebody wants to install, so the reuse premium disappears.

Tinning holds value better than most sellers expect. Tinned conductor to ASTM B33 is specified for damp, corrosive and marine locations, and it is bought by plants and contractors who need exactly that. Tinned surfaces dull to gray-brown rather than green, and a clean tinned coil in original packaging is a reusable product rather than a weighed lot.

• Size and stranding stated plainly — 4 AWG solid, or 250 kcmil 37-strand, not just 'ground wire'
• Temper: soft annealed and hard drawn are not interchangeable and are not priced the same
• Surface: bright bare, tinned, or oxidised, described honestly
• Package: original banded coil with a tag is worth more than a loose, tangled coil
• Contamination: solder, paint, steel ties, attached lugs and insulation remnants all reduce yield
• Weight per coil, and the count of coils in the lot