PVC Insulated Cables

Indian Standards Specification IS: 694-1977 Specification for PVC Insulated Cables for working voltage Upto and Including 1100 Volts covers the requirements and tests for unarmored PVC insulated cables with copper or aluminum conductors and flexible cords with copper conductor for electric power and lighting (including weatherproof cables) for voltages upto and including 1100 Volts. The type of cables covered in the specification for fixed wiring includes:

1. Single core (unsheathed)
2. Single core (sheathed)
3. Circular twin, three and four core (sheathed)
4. Flat twin with or without ECC (sheathed)
5. Flat three core (sheathed)

The cable covered in this standard is suitable for use on a.c. single phase or three phase (earthed or unearthed) system for rated voltages upto and including 1100 volts. These cables may be used on d.c. systems for rated voltages upto and including 1500 volts. They are suitable for use where the combination of ambient temperature and temperature rise due to load results in a continuous conductor temperature not exceeding 70oC.

As per the requirements of the standard, the conductor shall be composed of aluminum wires complying with IS: 8130-1976. The insulation and sheath shall be of PVC compound conforming to the requirements of Type I and Type 6 compound of IS: 5831-1970, respectively. The construction of conductors for cables for fixed wiring shall be as per Table 9.1.

Conductor of cables having their nominal cross sectional area less than 25 mm2 shall be circular only. Conductors having nominal cross sectional area 25 mm2 and above may be circular or shaped. The conductor shall be provided with PVC insulation applied by extrusion. The average thickness of insulation shall not be less than the nominal value specified in table by more than 10 percent of the specified thickness plus 0.1 mm. The insulation shall be so applied that it fits closely on the conductor and it shall be easily possible to remove it without damage to the conductor.