VFD Cable

Raw Material Verification
Copper rod, insulation compounds, shielding materials, armor materials, fillers, binding tapes, sheath compounds, and cable drums are inspected for material grade, dimensions, documentation, and surface condition before production.

Copper Wire Drawing
Copper rod is drawn into the required wire diameter while controlling roundness, surface quality, tensile properties, conductivity, and dimensional consistency.

Conductor Annealing
Where required, controlled annealing improves conductor flexibility, elongation, and processing performance for subsequent stranding and cable installation.

Conductor Stranding
Copper wires are stranded according to the required conductor class. Wire count, lay direction, lay length, conductor diameter, strand tension, and surface smoothness are carefully controlled.

Conductor Compaction
Compacted conductor designs may be used to improve roundness, reduce cable diameter, and create a stable surface for insulation extrusion.

Conductor Resistance Testing
Conductor resistance is measured and corrected according to the applicable reference temperature to verify electrical compliance before insulation processing.

Insulation Extrusion
XLPE, PVC, EPR, or project-specified insulation is extruded over each conductor. Extrusion temperature, insulation thickness, minimum thickness, eccentricity, surface finish, and cooling conditions are monitored continuously.

Online Spark Testing
The insulated conductors pass through online spark testing equipment to identify insulation discontinuities or defects before further cable assembly.

Core Identification
Phase conductors and grounding conductors are identified using insulation colors, printed numbers, longitudinal markings, or customer-specified identification methods.

Symmetrical Core Assembly
Phase conductors and grounding conductors are arranged according to the approved cable design. Correct symmetry helps support balanced electrical performance and improved electromagnetic compatibility.

Filler and Binding Application
Fillers are applied where required to maintain cable roundness and structural stability. Binding tapes secure the assembled core without damaging the insulation.

Shielding Application
Copper tape, copper braid, aluminum foil, or composite shielding is applied according to the required shielding design. Coverage, overlap, braid density, tension, continuity, and surface consistency are monitored.

 Inner Sheath or Bedding
For armored constructions, an inner sheath or bedding layer is applied to protect the cable core and provide a stable base for armor installation.

Armor Application
Steel tape or steel wire armor is applied where additional mechanical protection is required. Armor dimensions, coverage, tension, overlap, and cable geometry are inspected during production.

Outer Sheath Extrusion
PVC, PE, LSZH, TPE, or another specified sheath material is extruded over the completed cable assembly. Thickness, eccentricity, surface quality, overall diameter, and cooling are controlled.

Cable Printing and Meter Marking
The outer sheath is printed with the manufacturer name, cable designation, rated voltage, conductor size, standard, production batch, meter marking, and customer-specific information where required.

Electrical and Shielding Tests
Finished cables may undergo conductor resistance testing, insulation resistance testing, voltage withstand testing, continuity testing, shielding continuity verification, and other tests required by the applicable specification.

Dimensional Inspection
Conductor diameter, insulation thickness, shield dimensions, braid coverage, bedding thickness, armor dimensions, sheath thickness, overall diameter, and ovality are verified using calibrated equipment.

Rewinding and Length Verification
Finished cables are wound onto drums or reels while checking cable length, meter markings, bending radius, winding direction, cable ends, and drum loading.

Final Inspection and Release
Before shipment, the product model, length, drum number, markings, test records, packing condition, labels, shipping marks, and order documentation are reviewed. Only approved products are released for delivery.