| Sl. No. |
Description |
| 1.0 |
SCOPE : |
1.1 |
This specification covers the requirements and tests for armoured and unarmoured single core, twin core, three core and multi-core copper conductors PVC insulated and sheathed cables for railway signaling. This specification covers the complete requirement of underground (U/G), unscreened (U/S), Railway Power Cable.. |
| 1.2 |
The cable covered in this specification shall be suitable for use on AC systems (earthed or unearthed) for rated voltages upto & including 1100 volts. These cables may be used on DC systems for rated voltages upto and including 1500 volts to earth. |
| 1.3 |
The cables covered in this specification or suitable for use where the combination of ambient temperature and temperature rise due to load results in a conductor tempretaure not exceeding 70°C. |
| 2.0 |
GENERAL REQUIREMENTS : |
| 3.0 |
CONDUCTORS : |
| 3.1 |
The conductor shall be composite of plain, annealed high conductivity copper wire (s) complying with IS:8130 except for annealing test requirements. This diamensions, nominal weights and resistance of conductor shall be in accordance with the values given in Table-1. Any other sizes may be accepted as agreed between the purchaser and the manufacturer. In such cases, the wire diameter, the insulation thickness and the tolerances thereon shall be specified by the purchaser.
|
| 3.2 |
Conductors of nominal area less than 25 sq. mm shall be circular only. Conductors of nominal area 25 sq. mm and above may be circular or shaped. |
| 4.0 |
|
| 4.1 |
The insulation shall be of PVC compound conforming to the requirements of Type ‘A’ compound of IS:5831-84. (General purpose insulation for maximum rated conductor temperature 70°C operation) except for insulation resistance, tensile strength and percentage elongation. Re-cycled or re-claimed material shall not be used. |
| 4.2 |
The insulation shall be applied by extrusion in one continues process and shall be homogeneous and free from any joints or repairs it shall fit closely on the conductor but shall not adhere to it so that it is possible to remove it easily, without damage to the conductor. |
| 4.3 |
The cores of cables shall be identified by different colouring of PVC insulation. The colours shall conform reasonably with the standard colours shown in IS:9938. The following colour scheme shall be adspted :- |
| |
1 Core - Red, black, yellow, blue or grey. |
2 Core - Red and black. |
3 Core - Red, yellow and blue. |
4 Core - Red, yellow, blue and black. |
| 5 Core - Red, yellow, blue, black and grey. |
6 Core - Two adjacent cores ( counting and direction core) in each and above layer,
blue and yellow, remaining cores grey. |
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| 5.0 |
LAYING UP |
| 5.1 |
The cores of twin three and multi-core cables shall be laid-up together with suitable lay. The outermost layer shall have right hand lay and the successive layers shall be laid with opposite lay. Where necessary, the interstices shall be filed with mom hygroscopic material |
| 6.0 |
INNER SHEATH (Common Covering) |
| 6.0 |
LAYING UP : |
| 6.1 |
The laid up cores shall be provided with an inner sheath applied by extrusion. It shall be ensured that it is a circular as possible. |
| 6.2 |
The Inner sheath shall be so applied that it fits closely on the laid up core and it shall be possible to remove it without damage to the insulation. |
| 6.3 |
PVC used shall meet the requirements of type ST-1 (General purpose sheath for use at maximum rated conductor temp. 70°C) compound of IS:5831-84. Re-cycled or Re-claimed material shall not be used. The Colour of the PVC for Inner Sheath shall be either grey or black. |
| 7.0 |
ARMOURING : |
| 7.1 |
Armouring shall be applied over the insulation in case of single core cables and over the inner sheath in case of twin, three and multi-core cables. |
| 7.2 |
Armouring shall consist of the following :
- Galvanised round steel wire to IS:3975 except tensile strength and percentage elongation, or
- Galvanised steel strip to IS:3975 except tensile strength and percentage elongation or
- Any other material (as agreed between the purchaser and the manufacturer).
|
| 7.3 |
Where the calculated diameter below armouring does not exceed 13mm, the armour shall consist of galvanized round steel wires only. Wire armouring shall be applied upto 9 Core of 1.5 mm² conductor nominal cross sectional areas.
Above 9 Core of 1.5 mm² or any other sizes of conductor where the calculated diameter below armouring is greater than 13mm, the armouring shall consist of either galvanized round steel wire or galvanized steel strips.
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| 8.0 |
OUTER SHEATH : |
| 8.1 |
The outer sheath shall be applied by extrusion in one continuous process and shall be homogeneous and free from joints and repairs.
PVC compound conforming to the requirements of Type ST-1 compound to IS:5831-84. except for tensile strength, percentage elongation and shrinkage shall be used for outer sheath. The colour of the outer sheath shall be black. Re-cycled or Re-claimed material shall not be used. |
| 9.0 |
MARKING : |
| 9.1 |
The following information shall be legibly and indelibly indicated throughout the length of the cable by indenting or embossing of the cable. The identification or embossing shall only be done on the outer sheath.
- Name or trade mark of the manufacturer
- IRS Specification Number.
- Month and Year of Manufacturer.
- Drum Number.
- Size of the cable (e.g. 2 C x 25 sq. mm)
- Sequential length marking at every meter with an accuracy of ± 0.2%.
|
| 9.2 |
Finished cable is being supplied in non returnable wooden drum |
