How to read a reel tag and a jacket legend

Start with the tag, not the wire

The tag is usually stapled to the reel flange or wired to a spoke. It states the manufacturer, the product type, the conductor size, the voltage rating and the length originally on the reel. If the tag survives, you have most of what a buyer needs.

What the tag does not tell you is how much is left. That is measured, estimated from the wrap count, or read off the remaining length printed on the outer wrap.

Then read the print legend

Every cable has a legend printed along the jacket, repeated every foot or so. It reads like a sentence: manufacturer, type, size, temperature and voltage rating, and any listings. For example, a line that includes THHN or THWN-2, 12 AWG, 90C, 600V, and a sunlight-resistant mark identifies a 600-volt building wire rated for wet locations.

Photograph one clean stretch of that print. It is the single most useful photo in a surplus quote, because it resolves type and size without guessing.

Know what the common abbreviations mean

Type letters describe insulation and jacket, not the metal. THHN is thermoplastic, XHHW is thermoset, MC is metal-clad, TC is tray cable, USE-2 is underground service, SER is service entrance. The number after the letters sometimes indicates voltage class, as in 2kV.

Conductor size is either AWG (14 down to 4/0) or MCM/kcmil (250 through 1000 and above). Both appear on the same job, so a reel is never just large or small.

Four details that decide the value

1. Type and standard. A listed assembly with a legible legend is worth more than unidentified cable of the same size.
2. Size and metal. 4/0 aluminum and 4/0 copper are the same diameter and not the same material. A cut end settles it.
3. Footage. A full reel, a half reel and a 40-foot tail are three different transactions.
4. Condition. Intact jacket, no water intrusion, no UV cracking, no heat damage. Reel-end photos show most of it.