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|  XLPE Cables served by us are highly acclaimed in the market for their phenomenal workability. XLPE insulated cables or any others; you can rely on them in any tough conditions put before. Also, when it comes to rates, our XLPE insulated cables are available at the least prices than any other market. We are one of the major XLPE power cables manufacturers in India.
BAJAJ-XR Cross Linked Polyethylene Power Cables (XLPE)
Different types of cables in the voltage grade 1.1 to 33 kV are being used today in utilities and industries depending on their mechanical and electrical properti~s on one hand and economy in using them in the other. Among these, paper cables, ever since their introduction have been enjoying undisputed acceptability. However, the advent of XLPE cables in the late 70's marked the beginning of a gradual but steady replacement of paper cables especially for higher voltagE; applications.
XLPE cables could command an immediate acceptance resulting from their ease of handling, moisture proof sheathing, easier jointing procedures and ease of maintenance.
The XLPE range of cables offered by BAJAJ CABLES is known by its brand name BAJAJ-XR.
BAJAJ-XR cables of 6.6 kV to 33 kV grade are manufactured as per Indian Standard 7098 (Part II) of 1985.
PROPERTIES AND ADVANTAGES OF BAJAJ-XR CABLES
The excellent thermal properties of BAJAJ-XR cables permit maximum continuous conductor operating temperature of 90.C and short circuit temperature of 250.e. Moreover, it has very low dielectric loss which does not vary much over the entire operating temperature range.
These characteristics, alongwith the low dielectric constant make BAJAJ-XR cables particularly suitable for high voltage applications. Given below are additional outstanding features.
High Continuous Current Rating:
Its ability to withstand higher operating temperature of 90.C enables much higher current ratings than those of Pve.
High Short Circuit Rating:
Maximum allowable conductor temperature during short circuit of 250.C is considerably higher than for PVC cables resulting in greater short circuit withstand capacity.
High Emergency Load Capacity:
BAJAJ-XR cables can be operated even at 130.C during emergency, therefore in systems where cables are installed in parallel, failure of one of two cables will not bring down the system capacity because the remaining cables can carry the additional load even for longer duration until repairs/replacements are carries out.
Low Dielectric Losses:
BAJAJ-XR cables have low dielectric loss angle. The dielectric losses are quadratically dependent on the voltage. Moreover, these losses occur continuously in every charged cable whether it carries load or not. Hence use of XLPE cable at higher voltages would result in considerable saving in costs.
Charging Currents:
The charging current are considerably lower permitting dose setting of protection relays.
Easy Laying and Installation:
Low weight and small bending radii make laying and installation of cable very easy. The cable requires less supports due to low weight.
High Safety:
High safety against mechanical damage and vibrations.
APPLICATIONS
Because of the excellent mechanical and electrical properties BAJAJ-XR cables are being used extensively in all power stations and in industrial plants. They are ideally suited for chemical and fertilizer industries where cables are exposed to chemical corrosion or in heavy industries where severe load fluctuations occur and for systems where there are frequent over voltages. Cables can also be used at higher ambicol temperature on account of their higher
operating temperature. Their excellent installation properties permit the cable to be used even under most difficult
cable routing conditions and also in cramped conditions e.g. city distribution network. Single core cables due to their excellent installation properties are used in power stations, sub-stations and industrial plants with advantage.
CONSTRUCTION
BAJAJ-XR cables are manufactured and tested in accordance with 15:7098 (Part II) - 1985. Its salient constructional features are as under:
Conductor:
The conductors m,ade from electrical purity aluminium wires, are stranded together and compacted. All sizes of
conductors of single or three core cables are circular in shape. Conductor construction and testing comply to IS:
8130 - 1984.
Installation:
High quality BAJAJ-XR (XLPE) unfilled insulating compound of natural colour is used for insulation. Insulation is
applied by extrusion process and is chemically cross linked by continuous vulcanization process.
Shielding:
All BAJAJ-XR cables rated above 3.3 kV are provided with both conductor shielding and insulation shielding. Both conductor and insulation shielding consist of extruded semi-conducting compound.
Additionally, insulation is provided with semi-conducting tape and non-magnetic metallic tape screen over the extruded insulation.
Conductor shielding XLPE insulation and insulation shielding are all extruded in one operation by a special process. This process ensures perfect bonding of inner and outer shielding with insulation.
Inner Sheath (Common Covering):
In case of multicore cables, cores are stranded together with suitable non-hygroscopic fillers in the interstices and provided with common covering of plastic tape wrapping. As an alternative to wrapped inner sheath, extruded PVC inner sheath can also be provided.
Armouring:
Armouring is applied over the inner sheath and normally comprises of flat steel wires (strips) for multicore cables.
Alternatively, round steel wire armouring can also be offered. Single core armoured cables are provided with non
magnetic armour consisting of hard drawn flat or round aluminium wires.
Outer Sheath:
A tough outer sheath of heat resisting PVC compound is extruded over the armouring in case of armoured cables or over non-magnetic metallic tape covering the insulation or over the non-magnetic metallic part of insulation screening in case of unarmoured single core cables. This is always black in colour for the best resistance to outdoor exposure. The outer sheath is embossed the voltage grade and the year of manufacture. The embossing repeats every 300/350 rnrn along the length of the cable.
TESTING AND QUALITY CONTROL
BAJAJ-XR cables are manufactured under advanced manufacturing and testing facilities. The cables are type tested and routine tested in accordance with IS 7098.
The following tests are carried out as routine tests on every length of cable manufactured:
- Conductor resistance test
- Partial discharge test
- High voltage test
Test Voltages:
Test voltages applied between conductors and screen/armour are shown below in Table.
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| Voltage Rating of Cables | Test Voltage (for 5 minutes) | | 3.8 / 6.6 kV (E) | 12 kV (rms) | | 6.35 / 11 kV (E) | 17 kV (rms | | 11 / 11 kV (E) | 28 kV (rms | | 12.7 / 22 kV (E) | 32 kV (rms | | 19 / 33 kV (E) | 48 kV (rms |
In order to achieve consistency in quality, in addition to above tests, rigorous quality control measures are effected at every stage of production stage of production. Accirdingly, every batch of raw materials and inprocess cables are rested to check for their physical and electrical properties.
Besides standard types, these laboratories also possess special equipment for precision testing and quality control particularly for XLPE cable such as Instron Tensile Testing Machine, Melt Index Tester, Differential Scanning Calorimeter, Infra-red spectrograph, Oscillating Disc Rheometer, Microtomes, Blown Film Extruder etc.
Partial Discharge Detection in Finished Cables:
This is a modem PD detection equipment where the discharge magnitude can be directly read on a calibrated meter. The detector is associated with 50 kV noise-free transformer, discharge-free capacitor and suitable matching units. Besides, specially designs corona-free terminators are used for testing purposes.
Special Features of Partial Discharge Detector Laboratory:
The presence of partial discharge of even minute magnitude is not desirable in XLPE cables and hence a highly sensitive detector has been employed with the help of which discharges as low as 5 pcl cm can be detected. The noise from supply source is prevented by providing isolating transformer and low pass filters. The complete equipment is housed in C( specially shielded room to prevent external noise that would otherwise interfere with the measurements.
Short Circuit Rating of BAJAJ-XR Cables:
Thermally admissible short circuit currents for BAJAJ-XR cables of 6.6 kV to 33 kV grade is' calculated as:
Full load conductor temperature prior to short circuit: 90.C, Maximum short circuit conductor temperature: 250.C,
IK = 0.094 A/vt.
Where IK : Short circuit current in KA (rms)
t : Duration of short circuit in seconds
A : Area of aluminium conductor in mm2
OPERATING CHARACTERISTICS
The operating characteristics of BAJAJ-XR cables with aluminum conductor are based on standard conditions of installation as provided in Table.
| Maximum Continuous Operating Conductors Temperature | 90 deg. C | | Standard Ground Temperature | 30 deg. C | | Ambient Air Temperature | 40 deg. C | | Thermal Resistivity of Soil | 150 deg. C cm / watt | | Depth of Laying | 90 cms for cable upto 11 kV (E) or (UE) grade and 105 cms for 22 kV and 33 kV grade cables. | | Method of Installation | | | Three Core Cables | Insalled Independently | | Single Core Cables | Three cables in a trefoil touching each other. |
Arrangement for which reduction in current rating is not required:
For cables sizes up to 70 sq. mm. conductor section, reduction in rating for grouping for cable in air need not be applied, provided, the circuits are run with a clearance of atleast 7S mm and installed in a horizontal plane, when number of circuits are more than three. For cables above 70 sq. mm. conductor section, no reduction in rating should be applied provided the circuits are run with clearance of atleast 150 mm, and installed in a horizontal plane as and when the number of circuits exceed four.
Short time and Intermittent Rating:
As in the case of any other electrical equipment, electric cables also, although, designed to carry a continuous load with a specified temperature rise under defined ambient conditions; are capable of carrying loads in excess of such continuous rating for short duration without harmful effect.
If the cable are loaded cyclically having considerable no load or low load periods followed by short overload periods, the current carrying is comparatively higher than the normal current rating. However, this has to be worked out based on the actual working conditions.
Cables exposed to solar radiation:
To reduce the effect of solar radiation it is recommended that the cable should be shielded from the direct rays of the sun without restricting the ventilation. On account of heating of the exposed cable due to solar radiation the rating of the cable installed out-door and not shielded from the sun is less if shielded.
It is advisable to shield the exposed portion of the cable route from the direct rays of sun instesd for the entire rout.
KNOW THE SUPERIOR PRODUCT
The L T-XLPE Cable
- LT-XLPE cables have a higher conductor temperature rating i.e. 90'C as against 70'C of PVC and hence higher current rating.
- LT-XLPE cables have longer life as compared to conventional PVC Cables.
- Max. temperature limit under short circuit conditions for LT-XLPE Cables is 250'C as against 160'C for PVC Cables.
Hence, XLPE Cables have higher short circuit rating.
- LT-XLPE Cables have higher emergency overload capacity than PVC Cables (upto 60 %).
- The moisture resistance of LT-XLPE cables is nearly 100 times that of PVc.
- Insulation resistance of LT-XLPE Cables is very high compared to PVC (as high as 1000 times).
- LT-XLPE Cables have high corrosion resistance in polluted atmosphere as compared to PVC Cables.
- LT-XLPE Cables have low installation cost because of light weight, dimensions and are far more flexible.
- LT-XLPE cables have better properties of resistance to chemical and corrosive gases.
- LT-XLPE cables have better properties to withstand vibrations, hot impacts.
- Jointing of LT-XLPE Cables is easier and quicker.
- LT-XLPE Cables are ideal for transmission and distribution of power.
Click Here for Overall Diameter of 1.1 KV, 3.5 Core, XLPE / PVC Insulated, PVC Sheated (Armoured & Unamoured) Cables
Click Here for Current Rating (In Group) for XLPE Insulated 1.1 KV, Grade Cables
Click Here for Current Rating (InGroup) for XLPE Insulated 3.3 KV, Grade Cables
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