power cables

Constituents Code
Aluminum conductor A
Rallison XLPE insulation 2X
Steel round wire armour W
Steel strip armour F
Steel double round wire armour WW
Steel Double strip armour FF
Non-magnetic (A1) round wire armour Wa
Non-magnetic (A1) strip armour Fa
PVC outer sheath Y
 

Product Code
As per IS:7098 Part-1, the codes are:

Tests
In addition to all tests as required by IS:7098 Part-1, Rallison XLPE Cables are subjected to a number of in-house tests at every stage of production. Incoming raw material is also tested thoroughly to ensure consistency of quality.

Outer Sheath
Specially formulated heat resistant black PVC compound confirming to the requirement of Type ST-2 of IS:5831-1984, extruded to form the outer sheath. Rallison XLPE offers a specially formulated Flame Retardant Low Smoke Compound(FRLS) for outer sheath used in fire hazardous environment.

Armouring
Armouring is provided over the inner sheath to guard against mechanical damage. Armouring is generally of galvanized steel wires or strips (In single core cables used in AC system armouring is by non-magnetic hard aluminum wires/strips). Round steel wires are used where the diameter over the inner sheath does not exceed 13mm. Above 13mm, flat steel strip armour is used. Round wire of different sizes can be provided against specific request.

Inner Sheath
Laid up cores are bedded over with thermoplastic material for protection against mechanical and electrical damage.

Laying up
In multi-core cables, cores are laid up as per the above colour scheme, interstices are filled wherever necessary to make the laid up cores circular.

  Single core Black
  Two Core Red & Black
  Three Core Red, Yellow & Blue
  Four Core Red, Yellow, Blue & Black
  Three and half Core Red, Yellow, Blue and reduced neutral core in Black

Core Identification
Different colours identify the cores:

Insulation
Rallison's XLPE cables are specially made high grade cross-linked polyethylene for insulation by extrusion process.

Conductor
Conductors are made from electrolytic grade aluminium/copper conforming to IS:8130, and are compact circular or compact shaped.

General Construction of XLPE Cables

On cross-linking, slippage between flexible chains can be prevented. Cross-linked polyethylene (XLPE) is a thermosetting compound. It softens at the crytahne melting point of polyethylene (85