How to read a cable reel tag

What the tag is, and what it is not

A reel tag is the manufacturer's shipping and identification label. It is wired or stapled to one flange, often duplicated on the other, and sometimes a copy is rolled inside the drum or slipped under the outer wrap. It travels with the material from the factory to the utility store, from the store to the job, and, if you are fortunate, from the job back into the yard. The utility keeps a copy in its stores system. The drum keeps the original. When those two part company, the drum loses its identity and its price falls to the metal inside it.

It is not a test certificate and it is not a statement of condition. It says what was wound onto the reel on a particular day at a particular plant. Everything that has happened since — a winter in an open yard, a drop from a forklift, a flooded duct, twenty years in service — is absent from the tag. That gap is exactly where a buyer spends their time, and it is why a tag alone never closes a valuation.

Tags also get overwritten, and the overwriting is often more useful than the original. A running footage pencilled on the flange at the end of a pull, a cut recorded in marker, a stores label stapled over the mill label: these are the traces of what actually happened to the cable. Read all of them. Where a factory length and a handwritten remaining length disagree, the handwritten one is usually the truth, because somebody had a reason to write it down.

The fields, one at a time

Tags vary between manufacturers, but the same facts appear on almost all of them. The order below is roughly the order in which a buyer reads them, not the order in which they are printed.

Decoding the description line

The description line is a compressed specification, and it repays being read slowly. Take a typical medium-voltage string: 3-1/C 500 KCMIL CU 35 KV 133% XLPE 420 MILS CU TAPE SHIELD PVC JACKET. Seven pieces of information are packed into that.

The prefix tells you how many conductors and how they are arranged. 3-1/C means three single-conductor lengths, each handled separately, on its own reel or coil. A string beginning 3/C means one cable containing three insulated conductors under a single overall jacket, which is a different product with a different use and a different price. Next comes the conductor: 500 kcmil, copper. Kcmil means thousands of circular mils, so 500 kcmil is the same conductor that older drawings call 500 MCM. Then the voltage class — 35 kV here — followed by the insulation level as a percentage, the insulation type and its wall thickness in mils, the metallic shield, and the jacket.

Two of those deserve a sentence each. The percentage is an insulation level, not a grade or a score. A 100% cable is built for systems where a fault is cleared quickly; 133% is the heavier wall that most utility specifications default to and is the more saleable of the two. And the shield matters as much as the insulation: copper tape, concentric neutral wires, a lead sheath or a longitudinal drain wire all describe how the cable deals with charging current and fault current, and a buyer reading a description line is checking that the shield suits the system the cable would go back into.

Where the second copy lives

Before a tag fades, find the copies. The opposite flange usually carries a duplicate, and on wooden reels a stencil or paint-marked description is often applied directly to the flange face — that survives weather far better than a paper label. Steel reels frequently have the description stamped or stencilled on the side plate. Some manufacturers band a label under the outer wrap, so it appears when the first few feet come off, and some place a card inside the drum between the flanges.

This matters practically because the paper tag is the first thing to go. It fades in sun, it tears when a forklift brushes the flange, it is removed when a stores clerk files it, and it is soaked through within a season outdoors. If you are holding a reel with a legible tag, photograph it now and copy the essential line onto the flange in paint pen. That five minutes is worth more than any other preparation you can do before selling, because a legible description is the difference between a reuse buyer and a scrap buyer.

When the tag is gone

Work in a fixed order and stop as soon as the construction is established. First, the jacket print. Nearly all cable has a legend printed along its length, repeated every foot or two: manufacturer, size, voltage class, insulation, jacket, standard, and often the year. Clean a section with a rag, read it in raking light rather than direct sun, and photograph it flat. The print is the same information as the tag, applied by the same machine, and it is the single best substitute.

Second, the cut end. Square off the end if it has been crushed or bent, then look at it straight on. The conductor tells you copper or aluminum, stranded or solid, and roughly how many strands. The insulation shows as a ring whose thickness you can measure, and the shield, tape or wires sit outside it. Third, measure the outside diameter with a caliper or a pi tape and compare it against a cable table: diameter, insulation wall and conductor size together usually pin the construction down to one or two candidates.

Fourth, weigh it. A reel whose construction is known but whose footage is uncertain can be resolved with a scale and a weight-per-foot figure, which is the subject of its own guide. What weighing cannot do is recover a construction you have not identified, because the weight of a reel is the weight of its copper or aluminum plus insulation, jacket and drum, and those proportions change with every design.

• Read the jacket print along several feet, not one spot — print repeats and one section is often scuffed.
• Photograph the cut end square-on with a scale in frame before you cut anything further.
• Measure diameter over the jacket and over the insulation, and note both.
• Check the flange for a stencil, a stores label or a paint-pen length.
• Keep every fragment of the old tag in an envelope taped to the reel; a partial tag still proves a specification.

Six facts to write down before you call

A buyer can price a reel from a short, accurate message and cannot price one from a long, vague one. The list below is the whole of what is needed to start, and it is worth writing on the flange as well as sending, so that the reel and its description never separate again.

• The description line exactly as printed, including the standard and the year.
• The length claimed, and whether it comes from the tag, a stores record or your own measurement.
• Flange diameter and traverse, in inches.
• Reel number, serial or purchase order, if any of them survive.
• Storage history in plain terms: covered, open yard, on the ground, how many winters.
• Where it is and what can reach it — a dock, a gravel yard, a basement, a locked substation.