Building Wire / House Wire

Wires & Cables

SINGLE CORE, TWIN INSULATED WIRES IN VOLTAGE GRADE 650/1100V

Normal area of Conductor Number/Nom. Dia. of wire Thickness of Insulation (Nom.) Approx. Overall Diameter Current Carrying capacity*  Rating Resistance (Max.) Per km. @ 20 C
mm. mm. mm. sqmm amp. Sq. mm.
1.0 14/.3 0.7 2.8 11 18.10
1.5 22/.3 0.7 3.1 14 12.10
2.5 36/.3 0.8 3.8 19 7.41
4.0 56/.3 0.8 4.4 26 4.95
Standard Colours: Red, Yellow, Blue, Black & Green (for earthing). 
Supplied in 90 meter lengths in attractive cartons. Conform to IS 694:1990. ISI License No.CM/L-7167980

SINGLE CORE, UNSHEATHED WIRE IN VOLTAGE GRADE 650/1100 V.

Normal area of Conductor Number/Nom. Dia. of wire Thickness of Insulation (Nom.) Approx. Overall Diameter Current Carrying capacity*  Rating Resistance (Max.) Per km. @ 20 C
mm. mm. mm. sqmm amp. Sq. mm.
6 84/.3 0.8 5.2 31 3.30
10 140/.3 1.0 6.6 42 1.91
16 126/.4 1.0 7.8 57 1.21
25 196/.4 1.2 9.7 71 0.780
35 276/.4 1.2 10.9 91 0.554
50 396/.4 1.4 13.2 120 0.386
Standard Colours: Red, Yellow, Blue and Black. Other colours in request.
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Building Wire / Flame Retardant Low Smoke Cables

The Growing importance of flame retardance

Until recently flame retardance was never a major consideration when choosing a cable; physical performance and reliability always took precedence.In the recent past, however, growing awareness of fire hazards has resulted in the development of flame retardant low smoke cables.  Development, fuelled by devastation fires in power stations and elsewhere in the country: situations where cables laid in horizontal and vertical trays, spread extraneously caused fires.Generally outer, sheathing material is made of chlorinated polymers like PVC, CSP, PCP, etc., polymers which have inherent resistance to flame propagation. Yet, in the event of a fire, they propagate fire and release large volumes pf dense smoke, toxic gas and hydrochloric acid.  Flame retardant cables therefore should fulfill the following four criteria:

  • FlameRetardance in:Ability to restrict flame propagation
  • Low smoke Emission :Smoke emitted should not obscure visibility
  • Low Acid Gas Emission : Gases which when combined with water produce high corrosive acids which damage plant and equipment.
  • Low Toxic Gas Emission: Gases less injurious to health.

Flame Retardant Low Smoke (FRLS) Cables

Capital Cables has been in the forefront in the development of cables for applications where the fire associated phenomenon is of concern. The development of these cables needs the awareness of the environment in which the cables will be laid and probable situation in fire conditions. Capital Cables has subjected its cables to a rigorous evaluation under different fire situations. This development has been possible by the usage of various polymers and elastomers, designs and composites.

The three important considerations in the selection of cables are:-
  • The power requirements that cable has to meet with: The environment and special requirements like oil resistance, abrasion; resistance etc.
  • The possible consequences of fire and liabilities in the environment.
  • The cable specification must be evolved as a compromise by evaluating these considerations.

The design, construction and testing of FRLS cables is relevant to technical specifications such as IS:1554 Part I and II, IS:7098 Part I and II, etc. In addition, several special tests are carried of FRLS cables and constitute components to fulfill the needs of improved fire performance characteristics.

Special Tests

Over and above the standard tests, FRLS cables and its components are subjected to series of special tests to fulfill the need of improved fire performance characteristics.

Physical Testing

R&D and Quality Control in cable industry utilizes physical testing as a very important tool. Capital Cables has a modern Computerized tensile testing setup having facilities for optical extensometry, low and high temperature extensometry. The Computerized facility enables accurate control on evaluation.

Smoke Measurement

Smoke is a by-product of combustion, which is manifest by its opacity. Smoke however is particulate in nature. Hence the evaluation is based on optical methods and Gravimetric. The testing being environmentally influenced, the selection of the method is done accordingly. The common methods of testing are:-

ASTMD – 2843

This method is designed to test the smoke density in context to a fixed interval of time and defined environment. A sample of the material of fixed dimension is placed on a sample holder and a flame of specified intensity is applied for four minutes. The smoke generated is evaluated by the percentage obscuration on an optical system which is in the path of the smoke by measurements at intervals of 15 seconds. A plot of percentage obscuration against time is made and the percentage smoke density is calculated.

The area integration method actually gives a quantitative indication of the smoke generation potential of a material with respect to time.

ASTM E- 662

This is the latest method of evaluation of smoke characteristics which is based on optical principles but relates to assessment of generation of smoke in flaming and non-flaming mode of material.

The inference between the two standards is not comparable due to environmental differences yet both serve as comparatives for material behavior.

3 Meter Cube

The test has been adopted for evaluation of the cable as a whole from the aspects of smoke generation. Adaptations of this technique is done in the UITP and IEC standards.

The test involves an assembly of a 3 meter cube test chamber where in a meter length of cable or a number of cables are placed depending on diameter. The ignition is with an alcohol flame

Oxygen Index Test (LOI) as per ASTM-D 2863

The test serves to determine the oxygen concentration at room temperature which the vertically held specimen, which is ignited at its upper end, ceases to burn of its own accord within 3 minutes. This test is further extended to temperature index requirement. The test is a source to determine the temperature at 21% oxygen, when a vertical specimen which has been ignited at the top ceases to burn of its own accord within 3 minutes. The test indicates the relative capacity of the materials to resist combustion in the context of oxygen concentration in the atmosphere. The temperature index further enhances at a higher temperature.

HCL Liberation as per IEC-754

The problem of corrosion is quantitative after a fire incident. The corrosive emissions are a function of the basic components of the system that on decomposition by fire give our acidic fumes. In the case of PVC sheathing materials, it is Hydrochloric acid.

A sample of the cable compound is introduced in a tube furnace, which is subjected to a controlled rate of heating for a fixed period. The product of de-composition is collected in an alkaline media and the corresponding HCL evolved is estimated.

Apart from the tests on materials used in the cables, following test on finished cables are carried out:

Tests on electric cables under fire conditions as per IEC 332-1

Tests carried out on single vertical insulated cable sample.

Flammability Testing \-chimney test fir Class F3 as per Swedish Standard S5 4241475Under this test, a sample of the cable is suspended in the chimney and ignited by means of Ethanol fire.

Flame Tests as per IEEE standard 383, 1974

This test is for bunched cables via the vertical tray to determine their relative ability to resist fire.

Fire Survival (FS) Cables

An advanced range of Fire Survival or Flame Resistant Cables are also available. Even under severe fire conditions when the outer protection and insulation have been destroyed, circuit integrity to essential services such as fire extinguishing systems, safety alarms, emergency lighting, etc., is maintained by these cables. This enables controlled shutdown of the plant and evacuation of personnel to safe areas. This range of cables has very low smoke and low halogen emission figures.

In addition to all the tests that FRLS cables undergo, Fire Survival Cables are also tested to IEC recommendations 331 of 1970.

IEC-331 Test

A sample of the complete cable, 1200 mm long, shall have 100 mm of sheath or outer covering removed from each end. At one end of each cable, the conductors are suitably prepared for electrical connections and at the other end the exposed cores are spread apart to avoid contact with each other. The cable is held horizontally by means of clamp at each end. The middle portion of the cable is supported by metal rings, placed approximately 300 mm apart. Power supply of not less than 3 A capacity at the test voltage is provided. A 3 A fuse which is inserted in the circuit should not fuse during the stipulated test period.

Applications

FRLS and FS cables are specially designed for buildings and installations where a high degree of safety of personnel and equipment is envisaged. The cables are especially recommended for use in the following buildings and installations:

  • Hospitals
  • High rise buildings
  • Theatres
  • Hotels
  • Schools
  • Warehouses
  • Industrial Complex
  • Power Stations
  • Data Processing Centres
  • Underground trains
  • Offshore and onshore platforms