Table of Construction of Conductor for Cable for Fixed Wiring

Nominal Cross	Sectional Area	Solid/Stranded	Flexibility Class
Copper	Aluminum		Class of 1 of IS:
1 to 1.5	1.5	Solid	8130 - 1976
2.5 to 6	2.5 to 10	Solid/Stranded	- do -
10 and above	16 and above	Stranded	Class 2 of IS:
			8130 - 1976

Insulation Thickness of Single-Core PVC Insulated Cables (Unsheathed)

Nominal Cross Sectional Area of Conductor (mm2)	Nominal Thickness of Insulation (mm)	Nominal Cross Sectional Area of Conductor (mm2)	Nominal Thickness of Insulation (mm)
1.5	0.7	150	1.8
2.5 to 6	0.8	185	2.0
10 to 16	1.0	240	2.2
25 to 35	1.2	300	2.4
50 to 70	1.4	400	2.6
95 to 120	1.6	500 to 630	2.8

Cores shall be identified by different coloring of PVC insulation. As per the requirements of the specification following color scheme shall be adopted. In case of single-core cable used for control wiring of swich-gear, any color other than the below specified shall be permissible as agreed to between the purchaser and the supplier:

No of Cores	Color of Insulation for Cables for Fixed Wiring
1	Red, black, yellow, blue, white or grey
2	Red and black
3	Red, yellow and blue
4	Red, yellow, blue and black

As per the requirements of the specification, the laying up of cores shall be as follows:

1. In the case of flat, twin and three-cores cable (without ECC) two or three cores shall be laid side by side.
2. In the case of flat twin cables (with ECC) two cores with a bare ECC shall be laid side by side in the same plane (ECC occupying the central position)
3. In the case of circular twin, three, and four-core cables, the cores shall be laid together with a suitable right-hand lay. The interstices between the cores may be filled with unvulcanized rubber, thermoplastic material or any other suitable material. A binder tape of plastic material or proofed cotton may be applied over the laid-up cross areas. Vulcanized or unvulcanized rubber or thermoplastic material used as filling materials shall not be harder than PVC used for insulation and sheet.