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Power Control Cables
AJANTA heavy duty Armoured and Unarmoured cables are manufactured with Copper / Aluminium Conductors PVC Insulated laid, up the inner sheath may be extrusion / taping process and is of thermoplastic material. The Armouring is of galvanized mild steel wire / strip. For single E core Armoured cables intended to be used in A. C. Circuit, the Armouring is of non-ferrous metals to avoid eddy current heating and finally sheathed with higher grade PVC. The cables are manufactured under strict quality control as per IS specification No. S: 1554 (Part 1) of 1988 and are suitable for operation upto 1100 Volts.
Colour of cores
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Single core
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Red, Black, Yellow, or Blue
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Two Core
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Red & Black
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Three Core
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Red, Yellow & Blue
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Four Core
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Red, Yellow, Blue & Black
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Five Core
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Red, Yellow, Blue, Black and Grey
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Six Core and above
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Two adjacent cores, (counting and directional core) in each layer, Blue and Yellow respectively and remaining cores Grey
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INNER SHEATH
Cables of two or more cores have a common inner sheath. The minimum thickness of inner sheath is 0.03-mm upto laid up diameter of 25 mm.
ARMOURING
Where the calculated diameter of inner sheath doesn't exceed 13 mm the ARMOUR is of round galvanized steel wires and for calculated diameter of inner sheath above 13 mm flat galvanized steel strips are used.
OUTER SHEATH
The outer is of suitable grade PVC compound
CRITERIA FOR SELECTION OF POWER CABLES
The following factors should be taken in to account while selecting the correct size and of cables
SYSTEM VOLTAGE - What is the system voltage and the type of system? Single phase, Three phase, earthed or unearthed AC or DC?
CURRENT CARRYING CAPACITY - The current rating is the main and basic criterion. Tables enclosed give the current carrying capacity of various types and sizes of cables, under different conditions of laying. Following parameters should be considered before selecting the correct size of cables
- Depth of Laying.
- Ambient temperature of ground or Air.
- Soil resistivity.
- Whether one or more groups of the cables are laid together.
- Any heating source near cable run.
MODE OF INSTALLATION The mode of installation determines the type of cable to be used. Electricity regulations require the use of Armoured cables for underground applications. In general, Armoured cables are recommended where there is any chance of mechanical damage. If subsequent mechanical damage after laying cables is not likely, cheaper Unarmoured cables can be used.
PERMISSIBLE VOLTAGE DROP For longer length of cable run it is necessary it is necessary to check that with the cable size selected, the voltage drop does not exceed the prescribed regulations limit. A higher size cable may have to be used if the voltage drop limits are not to be exceeded. LOAD CHARACTERISTIC One should take into account the characteristics of load. It is essential to ensure that the cable selected is capable of handing temporary overloads. AJANTA cables permit a conductor temperatures of upto 85o C under temporary overload conditions.
SHORT CIRCUIT RATING Short circuit rating depends on the expected level and the expected duration of the short circuit. In certain cases a large size of cable than the cable required for normal full load may be needed. The cables with high KVA capacity are expected to carry short circuit currents of high magnitude, "AJANTA" permit a short circuit temperature of 160oC
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