Cu/XLPE/Cws/Lat/HDPE 76/132kv XLPE Insulated Power Cable

4. MANUFACTURING FEATURES
The conductor shall be round compact stranded copper wires. The resistance of each conductor at

20ºC shall be in accordance with IEC 60228 standard. The surface of the conductor shall be clean

and free from any foreign particles, which may contaminate the insulation or cause high electrical

field stress in the conductor screen.

Conductor screen, Insulation and Insulation screen

Extrusion of conductor screen, insulation and insulation screen shall be by single pass, triple

extrusion method. Conductor screen, XLPE main insulation and insulation screen shall be produced

by triple extrusion and dry curing.

Conductor screen shall consist of semi-conducting tapes applied over the conductor and a

continuous layer of extruded semiconducting XLPE compound covering the entire surface area of the

conductor and firmly bonded to the inner surface of the insulation.

The insulation shall be XLPE and shall be applied by extrusion and cross-linked to form a compact

and homogeneous layer in accordance with the Standards specified. The insulation material shall be

of Super Clean polyethylene mixture suitable for cross-linking (XLPE).

Insulation screen shall consist of a layer of extruded non-strippable semi-conducting thermosetting

compound.

After triple extrusion, the insulated cores shall be degassed to remove the by-product in the core from

the cross-linking process.

Bedding

Semi-conducting water-blocking tapes (swellable tapes) over the insulation screen shall be applied to

prevent longitudinal water penetration between insulation screening and metallic sheath. The

swellable tape(s) shall cover the entire surface area of the insulation screen.

Metallic screen

Plain copper wires and a layer of counter helix metallic copper tape shall be applied over the

semi-conducting water blocking tape to accommodate the required fault current.

Metallic sheath

A layer of AL-plastic composite tape shall be applied over the semi-conducting water blocking tape to

accommodate the required radical water tightness.

Outer sheath

The outer-sheath shall be of an extruded layer of black color High Density Polyethylene (HDPE).It

shall be highly chemical resistance and withstand the mechanical force during fabrication, transit,

installation and operation.

Outer conductive layer

A coating of Graphite shall be applied over the over sheath to carry out D.C. Voltage Test.