VFD cable: symmetrical grounds, overall shield, 1 kV and 2 kV
A drive cable is a construction rather than a voltage class. Three conductors, three grounds laid in the interstices, an overall shield and a jacket that says so are what make it useful.
- Three symmetrical grounds
- 1 kV and 2 kV
- TC-ER tray rated
The construction exists to solve a specific problem. A pulse-width modulated drive output switches fast enough to produce reflected waves at the motor terminals and common-mode current on the cable, so VFD cable is built with a symmetrical three-conductor core, three bare grounds laid in the interstices, and an overall shield, usually copper tape or a combination of tape and braid. Low-capacitance insulation keeps charging current down on long motor leads.
Ratings are typically 1 kV or 2 kV, with XLPE insulation and a robust jacket, and tray ratings such as TC-ER so the cable can leave the conduit. Sizes run from 16 AWG for small motors up to 500 kcmil and beyond for large drives. The 2 kV constructions exist for higher system voltages and for long motor leads, where the standing wave at the motor terminals is more severe.
What reaches a buyer is usually a partial reel from a project where the drive package changed, or a plant standardisation that left four sizes in the storehouse. Because the construction is specific, a reel of ordinary three-conductor tray cable cannot stand in for it, and a reel of VFD cable is easier to place than its copper content alone would suggest. The construction is what a drive engineer specified, and it is what a buyer is paying for.
What we buy in this family
Condition and documentation decide the basis, not the family alone. These are the forms this material usually arrives in.
- 1 kV and 2 kV VFD cable
- Three symmetrical grounds with overall shield
- XLPE insulated drive cable
- TC-ER tray rated constructions
- 16 AWG through 500 kcmil
- Partial reels from drive retrofit projects
- Copper tape and braid shielded types
Why the three grounds are the point
A conventional three-conductor cable has one ground, and it sits asymmetrically. At drive frequencies that asymmetry gives common-mode current a path with different impedance on each phase, and the result shows as noise, bearing current or nuisance trips on a drive that worked on a bench. Three grounds, one in each interstice, make the geometry symmetrical.
That is why we look at the ground count before anything else. A reel with two grounds instead of three, or with the grounds cut short at one end, is a different product from the one a drive engineer specified. Where the print is legible it states the construction, and where it is not, the exposed end tells you.
Shield condition and the things that ruin a drive cable reel
The shield carries common-mode current back to the drive, and it has to be continuous to do that. Corroded tape, a section crushed where the reel was set down on a fork pocket, or a shield cut back for termination and never re-made all change how the cable behaves at high frequency, and none of it shows in a photograph of a flange.
Storage damage matters more here than on ordinary power cable, because the jacket is the only protection for a thin metallic layer. A reel left in standing water wicks moisture under the jacket at a cut end and corrodes the tape from inside.
Sizing, footage and the retrofit market
Most of this cable moves through retrofits rather than new construction. A plant replacing DC drives, or adding variable speed to a pump station, orders cable to a drive package and ends up with a partial reel and a coil. The sizes left over are the sizes over-ordered, usually one step larger than the motor needed. Above 100 feet a tagged reel is material; below it, it is a repair length.
Where this cable turns up in the two states
Drives are everywhere in the Upstate. Automotive suppliers run presses, conveyors and paint shop fans on variable frequency drives, and each drive package brings its own cable specification, so one plant can hold four incompatible VFD constructions at once. That is good for a seller with tagged reels and hard for one with a pallet of cut-offs and no print.
The same is true at water and wastewater plants across the Piedmont and the coastal plain, where pump stations are retrofitted drive by drive, and at the paper and chemical sites that have been replacing DC drives for years. Charlotte data halls run drives on chilled water plant, though that cable is installed in conduit and rarely comes back out as surplus.
Coverage
North and South Carolina
Every city page carries the local industrial base and access notes. Start from a state hub if you are not sure which one applies.
If the material is in one of these states
VFD cable questions
Can I use ordinary tray cable for a VFD?
It will carry current, but it does not have the symmetrical ground construction or the overall shield, so the drive sees a different high-frequency environment and the installation may not meet the drive manufacturer’s requirements. At review we do not treat ordinary tray cable as VFD cable, and we do not pay for it as such.
What is the difference between 1 kV and 2 kV VFD cable?
Insulation thickness and system voltage. The 1 kV constructions cover the common 480 V and 600 V drive systems with margin for reflected waves. The 2 kV constructions are for higher system voltages and for long motor leads where the standing wave at the motor terminals is more severe. The two are not interchangeable where a design specifies one.
Does a damaged shield matter on a drive cable?
Yes, more than on ordinary power cable. The shield is the return path for common-mode current, and a shield that is broken, crushed or corroded along part of a length behaves differently at high frequency. A reel with shield damage over a section is a cut-back decision rather than a whole-reel loss, and we assess it on the reel.
Do you buy VFD cable cut-offs?
We do, as recovery material, and we will say plainly when short lengths are not worth separating. A rack of five-foot tails from a panel shop is a weight question. A 300-foot partial reel with the print intact is a different conversation, and that is the one worth having first if a storehouse holds both.
Send vfd cable details
Construction, footage, condition and pickup city. Photographs can follow once a buyer has replied.
Or email saleselectricalbuyers@gmail.com
- No fee and no obligation to sell.
- Written lot terms before anything moves.
- Pickup scheduled around your access rules.