What is LSF?
The term LSF is used for Low Smoke and Fumes compound. It is also known by the abbreviations LSZH- Low Smoke Zero Halogen and LSOH - Low Smoke Zero Halogen. This compound is used in applications where the cable is to emit low smoke and no halogen acid gases in the event of a fire so that the exit signs are clearly visible to people for escape. Since it does not contain halogen, no acidic gases are emitted while burning. LSZH – Low Smoke Zero Halogen.
Why does Zero Halogen Material have a test limit of 0.5% Halogen content?
Halogen is not present in LSF but the test method has an accuracy of +/- 0.5% hence, the specification has this value.
What is the operating temperature of PVC insulated building wire & XL-LSF insulated building wire?
Manufactured as per the ISI 694 standard, building wires are generally insulated with normal PVC insulation which has operating temperature of 70ºC. In cases where higher operating temperature and higher current carrying capacity is required then type HR PVC insulation can be offered which has operating temperature of 90ºC and the temperature of XL-LSF insulated building wire is also 90ºC.
What is G/Y in core identification?
It is the colour identification offered by means of bi-colour combination Green/Yellow colours. This colour combination is used for earthing. The distribution of colours is such that one of the colour covers at least 30% of the surface of the core while the other colour covers the remainder of the core surface.
What are the application areas of Mica Glass Taped - Fire Resistant (FR) cables ?
Fire resistant cables manufactured by VK Polyshell as per BS 7846 have special grade mica tape wrapping over the conductor. Mica as a mineral retains its insulation property even in case of extreme fire temperatures of up to 950°C. Mica tape over the conductor forms a tube when subjected to fire & provides a barrier to insulate the conductor and prevent short circuit. The areas of application for these cables include, 1.Essential safety circuits eg. fire detection, fire alarm etc. 2.Power supply to equipment used in fire fighting eg. sprinkler pumps, smoke extractors . 3.Services where circuit integrity is very important under fire conditions eg. special equipments in hospital.
What is the difference between RTD / Instrumentation Cable?
RTD Cables are be Triad Constructed. Instrumentation Cables are Pair constructed.
What is the difference between Unsheathed & Sheathed Single Core Cable as per IS-694?
Unsheathed - Only Core Insulation will be done and there will be no Sheathing. Sheathed - Sheathing will be done on Core Insulation.
What is the difference between Control & Instrumentation Cable?
Control Cables – They are generally Core Constructed. Instrumentation Cables – They are generally Pair Constructed with Shielding.
What does Type Test mean?
Type tests are the tests made before supplying, on a general commercial basis, a type of cable in order to demonstrate satisfactory performance characteristics to meet the intended application. These tests are of such nature that after they have been made, they need not be repeated, unless changes are made in cable materials or design or manufacturing process which might change the performance characteristics.
What is the range of approval for Type Test?
When type tests have been successfully performed on a type of cable with a specific conductor cross sectional area and rated voltage, the type approval is accepted as valid for cables of the same type with other conductor cross sectional areas and/or rated voltages subject to satisfaction of conditions set out in the IEC specification.
Why UV radiation resistant insulation is expected to have better life?
Polymers (specially Polyethylene) are known to be susceptible to UV radiation. Exposure to UV radiation for prolonged duration may result in developing surface-cracks. Hence Ducab add a special Ultra Violet Radiation resistant stabilizer package in the insulation materials. This protects the insulation from deterioration.
What is the difference between the Power & Control Cables?
Power Cables - No. of Cores 2,3, 3 1/2 & 4 Core Control Cables - Upto 63 Cores or above Standards Applicable for both - IS-694 & IS-1554.
What is the minimum installation bending radius of cable?
The minimum bending radius of cable is that radius below which the cables should never be bent. The minimum bending radius depends upon the type, voltage grade and construction of the cable. This value is provided wherever required by the customer. In practice wherever possible a generous bending radius should be used.
Why is it that some times the drums supplied have a smaller bending radius than recommended for installation?
Cables are supplied on the drums and are used only for transporting the cable from one place to other. Bending on the drum is carried out under controlled conditions in the manufacturing plant.
What is the Temperature with standability of PTFE & Fibre Glass?
PTFE - 250 Deg.C, FG Cables 400 Deg.C