The color of the sheath shall be black or any other color as agreed to between the purchaser and the supplier.
For weatherproof cables, the color of sheath shall be black only.
The difference between maximum and minimum measured values of overall diameter of sheathed circular cables shall not exceed 15 percent of the maximum measured value at the same cross-section.
2) Cable Construction (Up to 1.1KV)
Copper Cable up to 6mm2 =Solid/Stranded ,
Copper Cable up to 10mm2 =Solid/Stranded
Copper Cable above 6mm2 =Stranded ,
Copper Cable above 10mm2 =Stranded
3) Cable-Testing (Up to 1.1KV)
The core(s) shall be carefully removed from a sample approximately 3 m long from the finished cable. They shall be so immersed in a water-bath at 60±3ºC that their ends protrude at least 200 mm above the water-level. After 24 hours, a voltage of 3 kV (rms) shall be applied between conductors and water. This voltage shall be raised to 6 kV (rms) within 10 seconds and held constant at this value for 5 minutes. If the sample fails in this test, one more sample shall be subjected to this test, which should pass.
The cores which have passed the preliminary test given in 16.2.1 shall be subsequently tested with a dc voltage of 1.2 kV in the same water-bath at the same temperature. The conductors shall be connected to the negative pole and water to the positive pole of dc supply by means of a copper electrode.
The core shall withstand this dc voltage test for 240 hours without breakdown.
The voltage shall be applied continuously, but if there are any unavoidable interruptions during the 4 hours period, that period shall be increased by the time of interruptions. The total of such interruptions shall not exceed 1 hour otherwise the test shall be started again.
The cables and cords shall withstand without breakdown an ac voltage of 3 kV (rms) or a dc voltage of 7.2 kV applied for a period of 5 min for each test connection
Single-core cables shall be immersed in water at ambient temperature one hour before the testing and the test voltage shall be applied between conductor and water for the specified period.
Abstract of IS 1554
1) Insulation Color (up to 11 KV)
For reduced neutral conductors, the insulation color shall be black.
2) Arrangement of Marking (up to 11 KV)
For cables having more than 5 cores, the core identification may be done by numbers. In that case, the insulation of cores shall be of the same color and numbered sequentially, starting with number 1 for the inner layer. The numbers shall be printed in Hindu-Arabic numerals on the outer surface of the cores. All the numbers shall be of the same color which shall contrast with the color of the insulation. The numerals shall be legible.
When the number is a single numeral, a dash shall be placed underneath it. If the number consists of two numerals, these shall be disposed one below the other and a dash placed below the lower numeral. The spacing between consecutive numbers shall not exceed 50 mm.
3) Type of Armor(up to 11 KV)
Where the calculated diameter below armoring does not exceed 13 mm, the armor shall consist of galvanized round steel wires. Where the calculated diameter below armoring is greater than 13 mm, the armor shall consist of either galvanized round steel wires or galvanized steel strips.
4) Cable Identification/ Marking (up to 11 KV)
Type of Cable Legend: (i) Improved fire performance or Category C1 FR ( Cables in constrained areas, Does not propagate fire even when installed in groups in vertical ducts),(ii) Improved fire performance for Category C2 FR—LSH (Cables in constrained areas with limited human activity and/or presence of sophisticated systems)
Jignesh Parmar has completed M.Tech (Power System Control), B.E(Electrical). He is member of Institution of Engineers (MIE),India. Membership No:M-1473586.He has more than 14 years experience in Transmission -Distribution-Electrical Energy theft detection-Electrical Maintenance-Electrical Projects (Planning-Designing-Technical Review-coordination -Execution). He is Presently associate with one of the leading business group as a Deputy Manager at Ahmedabad,India. He has published numbers of Technical Articles in "Electrical Mirror", "Electrical India", "Lighting India","Smart Energy", "Industrial Electrix"(Australian Power Publications) Magazines. He is Freelancer Programmer of Advance Excel and design useful Excel base Electrical Programs as per IS, NEC, IEC,IEEE codes. He is Technical Blogger and Familiar with English, Hindi, Gujarati, French languages. He wants to Share his experience & Knowledge and help technical enthusiasts to find suitable solutions and updating themselves on various Engineering Topics.