Composition And Designation Of Finished Cables

4.11 The composition and designation of finished cables are given in the following table.

Sr. No.	Designation	Complete Bunched Cables overall Dia in mm	Total Mass approx in Kg/km
1	3 X 16+25	19	250
2	3 X 16+16+25	19	325
3	3 X 25+25	22	325
4	3 X 25+16+25	22	395
5	3 X 35+25	24	435
6	3 X 35+16+25	24	495
7	3 X 50+25	32	585
8	3 X 50+16+35	32	650

Note : The fires of the designation refers to the number and size of the phase conductor, the middle To the street lighting conductor (were provided) and the last to the bare messenger wire. The Sixes shown are the nominal sectional areas.

• XLPE insulation confirming IS-7098 (P.I) IS 14255.
• Cable Phase conductor or street Lightening conductor will confirm to IS-8130/1984 duly compacted.
• The messenger (neutral conductor) will generally confirm to IS-398 (Part 4) 1994 for Aluminium Alloy Conductors or ACSR Conductors duly compacted.

Insulation

The insulation shall be either of cross-liked polyethylene compound or of PE compound. Confirming to requirement given in Tables 2 and 3 respectively.

Sr. No. (1)	Tests (2)	Requirements (3)
1	Tensile strength	12.5N/mm2, Min
2	Elongation at break	200 percent, Min
3	Ageing in air oven: a) Treatment : Temperature Duration b) Tensile strength variation c) Elongation variation	1350C + 30C 7 days + 25 percent, Max + 25 percent, Max
4.	Hot set: a) Treatment : Temperature Time under load Mechanical Stress b) Elongation under load c) Permanent elongation (set) after cooling	200 + /-30C 15 Min 20 N/cm2 175 percent, Max 15 percent, Max
5.	Shrinkage: a) Treatment : Temperature Duration b) Shrinkage :	1300C + 30C 1 hour 4 percent, Max
6.	Water absorption (Gravimetric): a) Treatment : Temperature Duration b) Water absorbed	850C + 20C 14 days 1 mg/cm2, Max
7.	Volume resistively a) at 270C b) at 900C	1X1013 ohm –cm, Min 1X1011 ohm –cm, Min
8.	Carbon Black a) Content b) Dispersion	Under consideration

Sr. No.	Property	Requirements
1.	Volume resistively a) at 270C b) at 700C	1X1014 ohm –cm, Min 1X1012 ohm –cm, Min
2.	Tensile strength	10 N/mm2, Min
3.	Elongation at break	300 percent, Min
4.	Melt flow index	3, Max
5.	Vacant softening point	850C, Min
6.	Carbon Black a) Content b) Dispersion	Under consideration
7.	Environmental stress cracking	No cracks shall be visible to marked eye

The conductor (with protective barrier, wherever applied) shall be provided with cross-linked polyethylene or polyethylene insulation applied by extrusion.

Thickness of Insulation

The average thickness of insulation shall be not less than the nominal value (ti) specified in Table-4.

Nominal Area of Conductor	Nominal Thickness (ti)
mm2	mm
(1)	(2)
16	1.2
25	1.2
35	1.2
50	1.5
70	1.5
95	1.5

Tolerance Thickness of Insulation
The smallest of measured values of thickness of insulation shall not fall below the nominal value (ti) specified in Table 4 by more than 0.1mm + 0.1 (ti).

Application of Insulation
The insulation shall be so applied that it this closely on the conductor (or barrier, if any) and it shall be possible to remove it without damaging the conductor. The colour of insulation shall be black. Customer can opt other colour of insulation on specific demand.

Polyethylene Insualtion

The Polyethylene insulation shall generally confirms to IS:6474-1971. The following properties shall be maintained in routine production.

• Melt Flow Index : 0.5 or less
• Yield Stress : Not less than 8n/mm2
• Percentage Elongation : Not less than 350
• Carbon Black Content : Between 2 & 3
• Vicat Softening Point : Not less than 850C

Volume

• At 270 C : 1 X 1015 Ohm Cm (min)
• At 700 C : 1 X 1013 Ohm Cm (min)

8. Identification

8.1 Manufactures, Identification
The manufacturer shall be identified through out the length of the cable by means of a tape bearing the manufacturers name or trademark and year of manufacture. In case the above method cannot be employed, or if the purchaser so desires, colour identification threads in accordance with a scheme to be approved by the Bureau of Indian Standards (BIS) shall be employed. Normally identification details are embossed in any one of phase conductor.

8.2 Cable Identification
Cables with cross-linked polyethylene insulation shall be identified through out the length of the cable by the legend 'XLPE 90' and year of manufacture by a printed tape. No identification is required for polyethylene insulation.

Notes

• Single tape bearing manufacturer's name or trademark and the cable identification, that is, XLPE 90, if provided shall be acceptable against the requirement of 8.1 and 8.2.
• Identification required in 8.1 and 8.2 shall be given on any one of the insulated conductor of cables.

9. Packing And Marking

The cable shall be wound on a drum (see IS 10418: 1982) of suitable size and packed. The ends of the cable shall be sealed by non-hygroscopic material.

The cable shall carry the following information either stenciled on the drum or contained in a Label attached to it :

• Reference to this Indian Standard, fro example, Ref IS 14255:
• Manufacturer's name or trade - mark:
• Type of cable and voltage grade:
• Nominal cross-sectional area of phase conductor:
• Length of cable on the drum:
• Number of lengths on the drum (if more than one):
• Directions of rotation of drum (by means of an arrow):
• Gross mass;
• Country of manufacture; and
• Year of manufacture.

9.2 The cable (drum or label) may also be marked with the Standard Mark

Note
The use of the Standard Mark is governed by the provision of Bureau of Indian Standards Act, 1986 and the Rules and Regulations made there under. The details of conditions under which the license for the use of Standard Mark may be granted to manufacturers of producers may be obtained from the Bureau of Indian Standards.

9.3 Standard Length
The standard length of 500 with +5% and longer length shall be acceptable.

9.4 Non Standard Length
Non standard length no less than 50% of the standard length shall be accepted to the extent of 10% of the ordered quantity.