Brief Introduction of SWA Armored XLPE Power Cable

The cables are designed for distribution of electrical power with nominal voltage Uo/U ranging from 3.6/6.6KV to 19/33KV and frequency 50Hz. 

They are suitable for installation mostly in power supply stations, indoors and in cable ducts, outdoors, underground and in water as well as for installation on cable trays for industries, switchboards and power stations. 

This article mainly introduce the cable from the construction as following.

1 Conductor of SWA Armoured XLPE Power Cable :

Plain annealed copper or aluminium complying with IEC 60228/BS 6360. 

Copper conductors shall be stranded (class 2) and aluminium conductors shall be either solid or stranded (class 2).

2 Conductor Screen of SWA Armoured XLPE Power Cable: 

Extruded layer of semi-conducting cross-linkable compound is applied over the conductor and shall cover the surface completely.

3 Insulation of SWA Armoured XLPE Power Cable:

Insulation is of cross-linked polyethylene compound XLPE (GP8) conforming to Insulaton Screen Extruded layer of semi-conducting cross-linkable compound is applied over the insulation. 

6 Inner Covering & Fillers of SWA Armoured XLPE Power Cable

For cables with a collective metallic layer or cables with a metallic layer over each individual cores with additional collective metallic layers, semi-conducting inner covering and fillers shall be applied over the laid up cores. 

The inner covering is made of non hygroscopic material, except if the cable is to be made longitudinally watertight. 

The inner covering shall be extruded or lapped.

5 The extruded semi-conducting layer shall consist of bonded or cold strippable semi-conducting compound capable of removal for jointing or terminating. 

As an option, a semi -conducting tape may be applied over the extruded semi-conducting layer as a bedding for the metallic layer.

6 The screen is tightly fitted to the insulation to exclude all air voids and can be easily hand stripped on site.

7.Metallic Layer of SWA Armoured XLPE Power Cable

8 The metallic layer shall be applied over each core or applied as a collective screen. 

The metallic screen shall consist of either copper tapes or a concentric layer of copper wires or a combination of tapes and wires. 

The metallic layer provides an earth fault current path, capable of withstanding fault current to earth of 1000A for one second at maximum temperature 160°C. Copper wires are applied over the conducting water blocking layer with a minimum diameter of 0.5mm. 

And over the copper wires, copper tape with minimum thickness of 0.1mm can be applied helically with overlap.

9 Armour (for armoured cable) of SWA Armoured XLPE Power Cable

The armour consists of galvanized steel wire applied over the inner covering with diameter specified .

10 Separation Sheath (for armoured cable) of XLPE Power Cable 

The separation sheath comprises a layer of extruded PVC, PE or LSZH. 

The nominal thickness is calculated by 0.02Du + 0.6mm where Du is the fictitious diameter under the sheath in mm. 

The nominal separation sheath thickness shall not be less than 1.2mm.