5 kV to 35 kV substation cable in Cuyahoga County

Cable that came down out of the tray

Mill and forging plants retire medium voltage cable where it hangs. A feeder that ran from a substation to a motor control house for thirty years is de-energised, meggered, condemned on paper, and then cut loose at both ends by an electrician with a recip saw. What reaches the laydown is not a reel. It is a hundred-foot coil, a bundle dragged over a pipe bridge, or a length still sitting in an overhead tray waiting for a scissor lift.

Two things follow from that. The terminations are gone, so the stress cones and elbows that would describe the cable's history are in a bin somewhere else. And the footage is approximate until somebody walks the route. A cable schedule says 240 feet; the tray run measures 265 with the drops. On medium voltage that gap matters, because the material is heavy and the conductor content is being weighed against a length nobody has confirmed.

What a Cleveland medium voltage lot holds

The common constructions are three-conductor 15 kV EPR with a copper tape shield under a PVC or CPE jacket, single-conductor XLPE with a concentric neutral from older outdoor work, and 5 kV shielded cable that fed smaller substations and large drives. Conductor sizes run from 2 AWG up to 750 kcmil, and paralleled sets are normal wherever the load demanded them.

• 15 kV EPR, tape shield, three-conductor
• 25 kV and 35 kV single conductor, XLPE
• 5 kV shielded cable to large drives
• Bare concentric neutral, direct buried
• Spliced runs carrying two or three joints

Condition, test sheets and what a jacket will admit

Cable that has been in service is not judged on appearance. Jacket print gives the manufacturer, the voltage class, the conductor size and the insulation type, and if that print is still legible after three decades the cable deserves a closer look. Chalking, sun-crazing on a coil that sat outside, and a jacket that cracks when it is bent over a thumb are each a reason to slow down.

The other document is the plant's own test record. A feeder that failed an insulation resistance check or a partial discharge test was retired for a reason, and the sheet that says so travels with the material or it does not. Cable condemned for a fault at one point may be sound for the rest of its length, but that is a judgement made after the ends are taped and the run is measured.

How review and pickup run

Review starts with a two-foot sample off each end and a walk of the route with the plant electrician. Shield type, stranding, jacket material and print are recorded, and the length is either wheeled or taken from the schedule with the variance written down. Nothing is cut to length, loaded or valued before a written description exists on both sides.

Pickup inside Cleveland is a rigging job before it is a freight job. Coils out of an overhead tray are heavy and awkward, urban yards on the Flats leave little turning room, and a 48-foot trailer may not reach the door. Where a crane or a forklift has to lift a coil off a rack, the plant usually supplies it, and the load leaves against a weight ticket rather than an estimate.