LT Control Cable
LT cables use stranded copper conductors. Although small conductor of cables may use solid conductors. The overall assembly may be round or flat. Non-conducting filler strands may be added to the assembly to maintain its shape. Special purpose LT cables for overhead or vertical use may have additional elements such as steel structural supports. Some LT cables for outdoor overhead use may have no outer sheath.
Conductor
Annealed Bare Electrolytic Copper/ Aluminum Conductor
Insulation
Conductors are insulated with PVC Compound
Colour Identification:
- Single Core: Red, Yellow, Blue, Black, White, Greent
- Two Core: Red and Black
- Three Core: Red, Yellow and blue
- Four Core: Red, yellow, Blue & Black
- Five Core: Red, Yellow, Blue, Black & Light Grey
Laying of Cores
Cores are laid up with a suitable lay. The final layer direction shall be kept right hand lay.
Armouring
It is applied over inner sheath. It may consist of galvanized Round Steel wires or galvanized Flat Steel Strips conforming to IS 3975. Round Wire armouring is provided, where the calculated diameter under armour is 13.0 mm. Above this, armouring is either round wire/steel strip.
Outer Sheath
A final covering of PVC Compound, confirming to IS:5831-1984, is applied over Armouring in case of Armoured Cable or Over Inner Sheath in case of Unarmoured cable, called as “Outer Sheath”. The Insulation, Inner Sheath or Outer Sheath can be PVC, FRLS PVC or FRHF Compound, depending upon their application.