TECHNICAL CATALOGUE 1

Transcription

1 1 TECHNICAL CATALOGUE

2 Company Profile Silvassa Plant Thane Plant Mysore Plant RPG Cables, a division of KEC International Limited has established itself as one of the leading manufacturers of Power, Control & Telecommunication Cables in India. One of the oldest cable manufacturing company (1958), we have been serving the industries with quality cables for over 5 decades. The state-of-the art manufacturing plants are located at Thane for HT Cables upto 33 kv and EHV Cables upto 132 kv and Silvassa for LT Cables upto 1.1 kv (Power and Control). The manufacturing facility at Mysore manufactures LT Power and Control Cables, apart from Telecom Cables (Fiber Optic & Jelly Filled), Instrumentation, Fire Survival and Signaling Cables. RPG Cables also offers expertise in Turnkey contracts involving cable laying, jointing, testing and commissioning. To keep pace with the changing needs of the customers and requirement of cables for voltage grades above 132 kv, the company is coming up with a new manufacturing unit near Halol, Gujarat with capability to manufacture cables up to 400 kv. The brand name Asian is synonymous with stringent norms in quality, environment and safety management. The plants have been ISO 9000 and ISO certifed. RPG Cables has been making major export thrust in keeping with its global aspirations. We match international quality standards and cables can be designed to comply with required international standards. The division has also been given recognition by the Govt. of Maharashtra for achieving excellence in Exports.

3 Manufacture of LT Cables Asian brand LT Cables are being manufactured for over 50 years having presence in more than 10 countries. Since year 2000 LT cables manufacturing was shifted to SILVASSA and MYSORE plants from Thane. SILVASSA Unit LT cables are manufactured at Silvassa unit since year PVC insulated and XLPE insulated cables are manufactured upto 1000 sqmm (single core) and 630 sqmm (Multicore) conforming to IS, IEC & BS standards. Special cables, as per user requirement, such as screened drive cables, XLPE insulated Fire Survival Cables etc. are also manufactured. MYSORE Unit Incorporated in 1982, Mysore Plant started manufacturing Telecom Cables. LT Cables, manufacturing range was added in the year PVC insulated and XLPE insulated LT Power and Control Cables, Instrumentation Cables, Jelly Filled (Telecom) & Optic Fiber cables are manufactured to National and International standards. Unit is equipped to manufacture multi - tube, unitube, aerial bunched, armoured and un-armoured cables. 1

4 SPECIFICATION & CONSTRUCTION 1.1Kv cables are designed and manufactured based on the national (IS) & international (IEC, BS) standards and project based customer specifications. Following are the standard stages of cable design & manufacturing. CONDUCTOR - The current carrying component : KEC offer cables with Electrolytic Copper (Plain or Tinned) and Aluminium conductor in form of Solid, Stranded Circular, Compacted Circular and Shaped as per IS 8130, IEC & BS EN The sector shaped conductor are manufactured with pre-spiral lay which gives compact shape to the cable with reduced diameter at laid up stage. INSULATION - The dielectric barrier to meet rated voltage level : XLPE, the 90 C thermoset dielectric, is applied as insulation over the conductor by extrusion process. Cross Linked Polyethyelene (XLPE) as per IS , IEC , BS Laying up of Cores - The multi-cores are Laid-up with appropriate tooling to form a compact circular shape, PVC fillers can be applied (wherever necessary) to provide circular shape. INNERSHEATH - The bedding for armour : PVC / LSZH innersheath is applied as a protection over the laid up cores, Innersheath can be offered in two forms Extruded or Taped. Extruded PVC bedding of ST2/LSZH PVC as per IS 5831, IEC , BS Taped Bedding of Thermoplastic tape to be compatible with temperature rating of the cable as per IS , IEC ARMOUR - The mechanical protection (or Earthing element) of cable : Galvanised Steel Round Wire as per IS 3975, IEC , BS Galvanised Steel Flat Strip as per IS 3975, IEC For Single Core cables to be used in AC circuits Aluminium Round Wire or Flat Strip armour is provided to avoid magnetic hysteresis losses. For cables to be used in mines, required armour conductance (may be 75% to 40%) can be achieved by Double wire armour or by incorporating Tinned Copper Wires with Galvanised Steel Wires OUTERSHEATH - PVC / LSZH outersheath is applied by extrusion process generally Black in colour with sequential length marking and required details Printed with non-contact ink jet printer. Poly-Vinyl Chloride (PVC) as per IS 5831, IEC , BS Low Smoke Zero Halogen (LSZH) as per IEC

5 SPECIAL REQUIREMENTS KEC Cables can be custom designed & manufactured for special requirements as follows : FR innersheath & outersheath material can be offered to meet the requirement of reduced Flame propagation characteristics as per ASTM-2863, IEC Part 3. FRLS innersheath & outersheath material can be offered to meet the requirement of reduced Flame propagation characteristics and Low Smoke & Low acid gas emission as per ASTM 2843, ASTM-2863, IEC Part 3, IEC , SS Copper tape, Copper wires or Aluminium tape can be provided as shielding / screening over laid up cores or innersheath. Cables with LEAD sheath over bedding can be offered. Fire Survival cables : Heat barrier Glass backed mica tape can be applied over the conductor for Fire Survival cables to meet the test requirements of 750 C for 3 hours as per IEC Fire Survival Cables are used where the applications require circuit integrity during a fire mainly in Fire Alarm systems, sprinkler systems in schools, hospitals, shopping malls, cinemas etc. 3

6 TYPICAL CROSS SECTIONAL VIEW OF LT CABLES 1. - Copper or Aluminium (A) 2. Insulation - Type XLPE (2X) 3. Outersheath - ST2 PVC (Y) 1 Core Unarmoured Cable Typical Cable Codes : 2XY, A2XY 1. - Copper or Aluminium (A) 2. Insulation - Type " XLPE" (2X) 3. Innersheath - ST2 Extruded PVC {(P)} or Thermoplastic tapes {(T)} 4. Outersheath - ST2 PVC (Y) 2 Core Unarmoured Cable Typical Cable Codes : 2XY(P), 2XY(T), A2XY(P), A2XY(T) 1. - Copper or Aluminium (A) 2. Insulation - Type " XLPE" (2X) 3. Innersheath - ST2 Extruded PVC {(P)} or Thermoplastic tapes {(T)} 4. Outersheath - ST2 PVC (Y) 3 Core Unarmoured Cable Typical Cable Codes : 2XY(P), 2XY(T), A2XY(P), A2XY(T) 1. - Copper or Aluminium (A) 2. Insulation - Type " XLPE" (2X) 3. Innersheath - ST2 Extruded PVC {(P)} or Thermoplastic tapes {(T)} 4. Outersheath - ST2 PVC (Y) 3.5 Core Unarmoured Cable Typical Cable Codes : 2XY(P), 2XY(T), A2XY(P), A2XY(T) 1. - Copper or Aluminium (A) 2. Insulation - Type " XLPE" (2X) 3. Innersheath - ST2 Extruded PVC {(P)} or Thermoplastic tapes {(T)} 4. Outersheath - ST2 PVC (Y) 4 Core Unarmoured Cable Typical Cable Codes : 2XY(P), 2XY(T), A2XY(P), A2XY(T) 4

7 TYPICAL CROSS SECTIONAL VIEW OF LT CABLES 1. - Copper or Aluminium (A) 2. Insulation - Type " XLPE" (2X) 3. Innersheath - ST2 Extruded PVC {(P)} or Thermoplastic tapes {(T)} 4. Armoured - Aluminium Round wire / Flat strip 5. Outersheath - ST2 PVC (Y) 1 Core Armoured Cable Typical Cable Codes : 2XWaY(P), 2XWaY(T), 2XFaY(P), 2XFaY(T), A2XWaY(P), A2XWaY(T), A2XFaY(P), A2XFaY(T) Copper or Aluminium (A) 2. Insulation - Type " XLPE" (2X) 3. Innersheath - ST2 Extruded PVC {(P)} or Thermoplastic tapes {(T)} 4. Armoured - G.S.Round wire / Flat strip 5. Outersheath - ST2 PVC (Y) 2 Core Armoured Cable Typical Cable Codes : 2XWY(P), 2XWY(T), 2XFY(P), 2XFY(T), A2XWY(P), A2XWY(T), A2XFY(P), A2XFY(T) Copper or Aluminium (A) 2. Insulation - Type " XLPE" (2X) 3. Innersheath - ST2 Extruded PVC {(P)} or Thermoplastic tapes {(T)} 4. Armoured - G.S.Round wire / Flat strip 5. Outersheath - ST2 PVC (Y) 3 Core Armoured Cable Typical Cable Codes : 2XWY(P), 2XWY(T), 2XFY(P), 2XFY(T), A2XWY(P), A2XWY(T), A2XFY(P), A2XFY(T) Copper or Aluminium (A) 2. Insulation - Type " XLPE" (2X) 3. Innersheath - ST2 Extruded PVC {(P)} or Thermoplastic tapes {(T)} 4. Armoured - G.S.Round wire / Flat strip 5. Outersheath - ST2 PVC (Y) 3.5 Core Armoured Cable Typical Cable Codes : 2XWY(P), 2XWY(T), 2XFY(P), 2XFY(T), A2XWY(P), A2XWY(T), A2XFY(P), A2XFY(T) Copper or Aluminium (A) 2. Insulation - Type " XLPE" (2X) 3. Innersheath - ST2 Extruded PVC {(P)} or Thermoplastic tapes {(T)} 4. Armoured - G.S.Round wire / Flat strip 5. Outersheath - ST2 PVC (Y) 4 Core Armoured Cable Typical Cable Codes : 2XWY(P), 2XWY(T), 2XFY(P), 2XFY(T), A2XWY(P), A2XWY(T), A2XFY(P), A2XFY(T). Multicore Control Cable 1. - Copper or Aluminium (A) 2. Insulation - Type " XLPE" (2X) 3. Innersheath - ST2 Extruded PVC {(P)} or Thermoplastic tapes {(T)} 4. Armoured - G.S.Round wire / Flat strip 5. Outersheath - ST2 PVC (Y) Typical Cable Codes : 2XWY(P), 2XWY(T), 2XFY(P), 2XFY(T), A2XWY(P), A2XWY(T), A2XFY(P), A2XFY(T). 5

8 sectional (Note 1) TABLE-1A Technical Data for Class-2 conductor as per IS: Minimum No of wires Maximum D.C. Resistance Maximum A.C. Resistance Non Compacted C Circular (Circular / Shaped) Plain Copper Tinned Copper 6 Aluminium Plain Copper Tinned Copper Aluminium sq.mm CU AL CU AL ohm/km ohm/km ohm/km ohm/km ohm/km ohm/km Note 1 : s of 1.5 sq.mm to 10 sq.mm can be manufactured as per class-1 solid conductor as per IS TABLE-1B Technical Data for Class-5 Flexible Copper conductor as per IS: sectional Maximum dia of individual strand in conductor Maximum D.C. Resistance Maximum A.C C Plain Copper Tinned Tinned Plain Copper Copper Copper sq.mm mm ohm/km ohm/km ohm/km ohm/km

9 TABLE: 2 - CAPACITANCE 1.1kV XLPE INSULATED CABLES - APPROXIMATE CAPACITANCE (microfarads/km) sectional Single Core Two Core Multicore (More than Two Cores) sq.mm Unarmoured Armoured TABLE 3 - REACTANCE 1.1kV XLPE INSULATED CABLES - APPROXIMATE REACTANCE (ohms/km) sectional Single Core Multicore sq.mm Unarmoured Armoured

10 TABLE 4 A- IMPEDANCE (Plain Copper 90 C 1.1kV XLPE INSULATED CABLES - APPROXIMATE IMPEDANCE (ohms/km) sectional Single 90 C 90 C sq.mm Unarmoured Armoured TABLE 4 B- IMPEDANCE (Aluminium 90 C 1.1kV XLPE INSULATED CABLES - APPROXIMATE IMPEDANCE (ohms/km) sectional Single 90 C 90 C sq.mm Unarmoured Armoured

11 TABLE 5 A- VOLTAGE DROP (Plain Copper 90 C 1.1kV XLPE INSULATED CABLES - APPROXIMATE VOLTAGE DROP (mv/a/m) sectional Single 90 C 3 90 C sq.mm Unarmoured Armoured TABLE 5 B- VOLTAGE DROP (Aluminium 90 C 1.1kV XLPE INSULATED CABLES - APPROXIMATE VOLTAGE DROP (mv/a/m) sectional Single 90 C 3 90 C sq.mm Unarmoured Armoured

12 TABLE 6 - SHORT CIRCUIT CURRENT RATINGS 1.1kV XLPE INSULATED CABLES - Short Circuit Ratings for 1 second sectional XLPE Insulated (for 90 C) sq.mm Copper Aluminium ) Maximum Initial temperature before short circuit : for linked polyethelen (XLPE) - 90 C 2) Maximum final temperature during short circuit : 250 C Short Circuit Rating for other duration can be calculated from : I sct = Short Circuit rating for "T" seconds I sc1 = Short Circuit rating for one second T = Duration in seconds BASIC ASSUMPTION FOR CURRENT RATINGS & RATING FACTORS SCOPE The current ratings of cables as indicated in various tables have been calculated on certain assumed conditions. In actual practice these conditions may be different. Therefore to determine the actual current ratings as per installation conditions, the tabulated ratings shall be multiplied with appropriate factors BASIC ASSUMPTION FOR CURRENT RATINGS Maximum permissible temperature - 90 C for Cross linked polyethylene Ground/Duct temperature - 30 C Ambient temperature - 40 C Thermal resistivity of soil C cm/w Depth of laying for 1.1kV cables mm Single core cables installed in one circuit in following arrangement Multi core cables installed in single circuit 10

13 TABLE 7 - CURRENT RATINGS Current Ratings for 2 Single Core Unarmoured / Armoured Cables according to IS sectional Direct in Ground (30 C) Amp. Direct in Duct (30 C) Amp. Direct in Air (40 C) Amp. Copper Aluminium Copper Aluminium Copper Aluminium sq.mm XLPE XLPE XLPE XLPE XLPE XLPE Note : Normal current ratings are given in standard conditions, if site conditions are different, current rating should be multiplied by rating factor as given in page no. 19 to 21 TABLE 8 - CURRENT RATINGS Current Ratings for 3 Single Core Unarmoured / Armoured Cables according to IS sectional Direct in Ground (30 C) Amp. Direct in Duct (30 C) Amp. Direct in Air (40 C) Amp. Copper Aluminium Copper Aluminium Copper Aluminium sq.mm XLPE XLPE XLPE XLPE XLPE XLPE Note : Normal current ratings are given in standard conditions, if site conditions are different, current rating should be multiplied by rating factor as given in page no. 19 to 21 11

14 TABLE 9 - CURRENT RATINGS Current Ratings for 2 Cores Unarmoured / Armoured Cables according to IS sectional Direct in Ground (30 C) Amp. Direct in Duct (30 C) Amp. Direct in Air (40 C) Amp. Copper Aluminium Copper Aluminium Copper Aluminium sq.mm XLPE XLPE XLPE XLPE XLPE XLPE Note : Normal current ratings are given in standard conditions, if site conditions are different, current rating should be multiplied by rating factor as given in page no. 19 to 21 TABLE 10 - CURRENT RATINGS Current Ratings for 3, 3.5, 4, 5 Cores Unarmoured / Armoured Cables according to IS sectional Direct in Ground (30 C) Amp. 12 Direct in Duct (30 C) Amp. Direct in Air (40 C) Amp. Copper Aluminium Copper Aluminium Copper Aluminium sq.mm XLPE XLPE XLPE XLPE XLPE XLPE Note : Normal current ratings are given in standard conditions, if site conditions are different, current rating should be multiplied by rating factor as given in page no. 19 to 21 Note : For 3.5 Core cables consider cable size above 16sqmm conductor area.

15 TABLE 11 - THICKNESSES Insualtion, Innersheath, Outersheath Thicknesses of XLPE Insulated Cables according to IS sectional Minimum Innersheath Thickness Single Core Armoured Multicore & Single Core Unarmoured Minimum Innersheath Thickness Minimum Outersheath Thickness (Flat strip armoured cable) Minimum Outersheath Thickness (Round wire armoured cable) Nominal Outersheath Thickness (Unarmoured cable) 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core sq.mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm

16 sectional Approximate O.D. ( +/-2 mm) - Un-armoured TABLE 12 - OVERALL DIAMETER (OD) Overall Diameter of XLPE Insulated Cables according to IS Approximate O.D. ( +/-2 mm) - Flat strip armoured Approximate O.D. ( +/-2 mm) - Round wire armoured Nominal Diameter of Round wire armour 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core sq.mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm mm

17 TABLE 13 - WEIGHTS Approximate Nett Weight of Copper, XLPE Insulated Cables according to IS sectional Approximate Nett Weight - Unarmoured Approximate Nett Weight - Flat strip armoured Approximate Nett Weight - Round wire armoured 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core sq.mm kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km sectional TABLE 14 - WEIGHTS Approximate Nett Weight of Aluminium, XLPE Insulated Cables according to IS Approximate Nett Weight - Unarmoured Approximate Nett Weight - Flat strip armoured Approximate Nett Weight - Round wire armoured 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core sq.mm kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km kg/km

18 TABLE 15 - CONTROL CABLES 1.5sq.mm Multi core Control XLPE Insulated Cables according to IS Number of Cores Minimum Inner sheath Thickness Minimum Outer sheath Thickness Round wire armoured Flat strip armoured Nominal Outer sheath Thickness Round wire Un- dia armoured Approximate Overall Diameter Nett Weight of Cable Round wire armoured Flat strip armoured Unarmoured Round wire armoured Flat strip armoured Unarmoured In Ground (30 C) Current Ratings (TYPE A 70 C PVC) In Duct (30 C) In Air (40 C) Standard Drum Length mm mm mm mm mm mm mm mm kg/km kg/km kg/km Amps Amps Amps mtrs Note : Normal current ratings are given in standard conditions, if site conditions are different, current rating should be multiplied by rating factor as given in page no. 19 to 21 16

19 TABLE 16 - CONTROL CABLES 2.5 sq.mm Multi core Control XLPE Insulated Cables according to IS Number of Cores Minimum Inner sheath Thickness Minimum Outer sheath Thickness Round wire armoured Flat strip armoured Nominal Outer sheath Thickness Round wire Un- dia armoured Approximate Overall Diameter Nett Weight of Cable Round wire armoured Flat strip armoured Unarmoured Round wire armoured Flat strip armoured Unarmoured In Ground (30 C) Current Ratings (TYPE A 70 C PVC) In Duct (30 C) In Air (40 C) Standard Drum Length mm mm mm mm mm mm mm mm kg/km kg/km kg/km Amps Amps Amps mtrs Note : Normal current ratings are given in standard conditions, if site conditions are different, current rating should be multiplied by rating factor as given in page no. 19 to 21 17

20 TABLE 17 - STANDARD DRUM LENGTH FOR 1.1kV XLPE COPPER POWER CABLES sectional Unarmoured Cables Armoured Cables 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core sq.mm STANDARD LENGTH (MTS) WITH +/-5% TOLERANCE STANDARD LENGTH (MTS) WITH +/-5% TOLERANCE Note : For multicore copper cables above 400 sq.mm steel drum required. TABLE 18 - STANDARD DRUM LENGTH FOR 1.1kV XLPE ALUMINIUM POWER CABLES sectional Unarmoured Cables Armoured Cables 1 Core 2 Core 3 Core 3.5 Core 4 Core 1 Core 2 Core 3 Core 3.5 Core 4 Core sq.mm STANDARD LENGTH (MTS) WITH +/-5% TOLERANCE STANDARD LENGTH (MTS) WITH +/-5% TOLERANCE Note : For multicore copper cables above 400 sq.mm steel drum required. 18

21 Method of Installation The current ratings are also based on the following methods of installation: A) Single core cables: Type of Installation Method of Installation a) Laid direct in the ground : i) Three cables in close trefoil formation or ii) Two cables touching in horizontal formation. b) In air : i) Two single-core cables are installed one above the other & fixed to a vertical wall as follows: the distance between the wall & the surface of the cable being 25 mm in each case. B) Twin & Multi-core cables : Installed singly in ground & in air. Cables of sizes upto & including 185 mm 2 are installed at a distance between centres of twice the overall diameter of cable. Cables if sizes 240 mm 2 & above are installed at a distance between centres of 90mm. The ratings for two cables may be applied with safety in case where such cables are installed in horizontal formation, on brackets fixed to a wall, either spaced as indicated above or touching throughout. ii) Three single-core cables are installed in trefail formation touching. A) RATING FACTORS i) Rating factors related to variation in ambient air temperature Air temperature in Deg. C Rating factor XLPE ii) Rating factors related to variation in ambient ground temperature Ground temperature in Deg. C Rating factors XLPE Depth of laying B) RATING FACTORS i) for depth of laying (Cables laid direct in the ground) Size cm up to 25mm 2 25mm 2 up to above 300mm 2 above 300 mm & above

22 Nominal area of conductor mm 2 Nominal area of conductor mm 2 ii) for variation in thermal resistivity of soil (twin & multi-core Cables laid direct in the ground) for value of thermal Resistivity of soil in C cm/w iii) for variation in thermal resistivity of soil (2 & 3 single-core Cables laid direct in the ground) 2 cables touching, for value of thermal Resistivity of soil in C cm/w 3 cables in Trefoil touching, for value of thermal Resistivity of soil in C cm/w A) GROUP RATING FACTORS For single core cables laid in Trefoil formation A) Cable laid in ground in horizontal formation B) Cable laid in Trefoil Ducts in horizontal formation No of Trefoils in group Distance/Spacing between trefoils No of Trefoils Distance/Spacing between trefoils Touching 15 cm 30 cm 45 cm in group Touching 15 cm 45 cm

23 C) Cable laid on Racks / Trays in covered trench with removable covers where air circulation in restricted, Trefoils are seperated by two cable diameter horizontally and the trays are in tiers with 30 cm. gap between them. D) Cable laid in open air trench, Trefoils are seperated by two cable diameter horizontally and the trays are in tiers with 30 cm. gap between them. No of racks / Trays in tiers No. of trefoils in Horizontal No of No. of trefoils in Horizontal formation racks / Trays formation in tiers B) GROUP RATING FACTORS For Multi-core cables A) Cable laid inside concrete trench with removable covers, on cables trays where air circulation is restricted, the cables are spaced by one cable diameter & trays are in tiers by 300 mm. The clearance from the wall is 25 mm. No of Cable trays in tier No. of cables B) Cable laid on trays exposed to air, the cables are spaced by one cable diameter & trays are in tiers by 300 mm. The clearance between the wall & the cable is 25 mm. No of Cable trays in tier No. of cables B) Cable laid on trays exposed to air, the cables touching & trays in tiers by 300 mm. The clearance between the wall & the cable is 25 mm. No of Cable trays in tier No. of cables D) Cable laid direct in ground in horizontal formation E) Cable laid in single way duct/pipes in horizontal formation No of Trefoils in group Distance/Spacing between trefoils No of Trefoils Distance/Spacing between trefoils Touching 15 cm 30 cm 45 cm in group Touching 15 cm 30 cm 45 cm

24 GUIDANCE ON HANDLING, STORING & LAYING OF POWER CABLES Handling (Unloading at site) : Damage to cables can occur due to the incorrect handling to which the drums & cables may be subjected, causing breakdown of the drum flanges & in exceptional cases,movement of the drum barrel takes place. The cable drums should not be dropped or thrown from railway wagons or trucks during unloading operations as the shock may cause serious damage to cable layers. A crane should be used for unloading cable drums. When lifting drums with the crane, it is recommended that the lagging should be kept in place to prevent the flanges from crushing on to the cable. If the crane is not available, a ramp should be prepared with approximate inclination. The cable drum should be rolled over the ramp by means of ropes and winches. Additionally a sand bed at the foot of the ramp may be prepared to brake the rolling of the cable drum. Cable should not be dragged along the earth surface. Cable ends should always be sealed by means of suitable end sealing materials to prevant moisturisation of cores and armour. Drums should be rolled in direction of arrow marked on the drum. Storage : Cables should be stored in a dry covered place to prevent exposure to climatic conditions and wear and tear of wooden drums and it should preferably be on a concrete firm surface which will not cause the drums to sink and thus lead to flange rot and extreme difficulty in moving the drums. All drums should be stored in a manner to leave sufficient space between them for air circulation. It is desirable for drums to stand on battens placed directly under the flanges. In no case should the drums be stored, On the Flat, i.e., with flange (see fig.) Cables should be protected from direct rays of the sunrays by leaving the battens on or by covering the cables with thick black polythene sheet. Note:- Cable ends must be sealed with end caps during storage & transportation. Laying : For laying of cables special care is to be taken to prevent sharp bending, kinking, twisting. Cable should be unwound from drum by proper mounting of the cable drum on a cable wheel and ensuring the spindle strong enough to carry the weight without bending and that it is lying horizontally in the bearings so as to prevent the drum creeping to one side or the other while it is rotating. It is important that the rolling of the drum to this position should be in accordance with the arrow on the flange-to prevent loose turns during unwinding. Provision should be made to break the drum to avoid further rolling & buckling of cable during sudden stop. A simple wooden plank can serve this purpose. Cable must be pulled from the top This is incorrect way of pulling the cable & will cause kinks & twist in cable. Shall be avoided at all 22

25 However, following salient points are to be considered during laying procedure of cables laid in racks and in built-in trenches. Before laying cables shall be checked with megger as a primary check. During laying try to place power cables at the bottom most layer and control cables at the top most layer. Single core power cable for use on A.C. system shall not pass through steel conduit or shall not be surrounded by steel which may lead to heat generation due to magnetic hysteresis. In case of multicore power cables, cables shall be laid side by side, with spacings not less than one cable diameter. However derating factors for cables laid on trenches are to be referred. The clamps shall not be placed at intervals more than 1200 mm. for horizontal and 1000 mm. for vertical runs. Where the cables are necessarily laid & jointed in very cold regions, both the cables & the ambient temperatures should be above 0 C & the cable should not be bent to very small radius. This is due to the reason that at very low temperatures PVC compound become stiff & brittle & are likely to crack & shatter when struck hard or bent to small radius. A joint being the weakest point of the electric power transmission system,the jointing work should be made skillfully. In this connection, it is always advisable that the method & the working instruction of the supplier should be strictly followed. For armoured cables all bonding clamps at the joints and terminations and the armour wires should be thoroughly cleaned. The clamps should be adequately tightened. This is necessary to ensure proper electrical contact, because armour is the only return path for earth fault current. For Unarmoured cables the external earth bonding connector of adequate size should be used. All joints, terminations, armour wires and external metallic bonding should be connected to earth. Wherever possible armour at one end of cable should be connected to main earth system of the supplying end with metallic connectors. The design of the junction box and the composition of the filling compound should provide effective sealing against ingress of moisture to conductor ferrules/lugs and armour connectors. After installation 4kV dc voltage, increased gradually, shall be applied to the cable for 15minutes to each core against the balance cores and armour. No breakdown should occur during the test. Minimum Bending Radius for L.V. Cables:- Type of cables : Minimum internal radius of bend Single core Cables : 15 D Multi core Cables : 12 D Where D is the overall diameter of cable. R Maximum permissible tensile strength for cables A) Maximum safe pulling force for cables (when pulled by pulling eye) :- For Copper Cables For Aluminium Cables B) Side wall Pressure :- = 5.0 Kgf x number of cores x conductor -section = 50 N x number of cores x conductor -section = 3.0 Kgf x number of cores x conductor -section = 30 N x number of cores x conductor -section (Subjected to maximum of 2000kgf or 20,000 N) = (Maximum Pulling force(kgf x 100 ) /Minimum Bending Radius(mm) (Subject to a maximum of 500kgf or 5,000 N/m) C) For cables pulled with stocking :- Armoured cables P = 9 D 2 Unrmoured cables P = 9 D 2 Where, P = Pulling force in Newtons D = Outer diameter of cables in mm 23

26 Manufacturing Process for for LT PVC LT PVC Cables Cables CONDUCTOR WIRE DRAWING / ANNEALING / STRANDING INSULATION CURING LAYING UP SCREENING (OPTIONAL) INNERSHEATH EXTRUDED / TAPED ARMOUR G. I. ARMOUR / AL ARMOUR OUTERSHEATH TESTING PACKING 24

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28 KEC is one of the oldest players in the industry and global leader in the Infrastructure Engineering, Procurement and Construction space. Established in 1945, KEC has a signifcant presence in the segments of Power Transmission & Distribution, Cabling, Railway, Telecom and Water Resource management. KEC s strengths lie in Engineering, Design, Manufacture and Testing, supply of transmission towers, telecom towers, cables and Construction of turnkey infrastructure projects. KEC s focused approach towards project management enables the creation of world class products, innovative solutions, customized to overcome extreme terrain and climate. With proven technical process in handling mega projects and superior project management expertise, KEC has made an indelible mark on the world map by constantly and consistently reengineering itselfto retain its position of leadership in the areas of quality, technology, capacity and capability. RPG Enterprises is one of India s largest business conglomerates. Since its inception in 1979, RPG Enterprises has been one of the fastest growing business houses in India. RPG Enterprises has diverse businesses under its fold ranging from Power, Tyres, Infrastructure, IT to Pharma. The Group s management comprises individuals extensively qualifed and experienced in their domain areas. RPG s wide ranging business invite growing returns and high esteem in the eyes of all its stakeholders. The Group lives by values of keen entrepreneurial skills, performance and excellence. Corporate Office 6th Floor, RPG House, 463. Dr. Annie Besant Road, Worli, Mumbai , India. Tel.: , I Fax : powercables@kecrpg.com I telecomcables@kecrpg.com I exportcables@kecrpg.com Works Thane : II Pokharan Road, PB No. 11, Thane, Pin , Maharashtra, India. Silvassa : Plot No. 273/4, Demni Road, Dadra, Silvassa, Pin , UT of D & NH, India. Mysore : 349/350, Hebbal Industrial, Hootgalli, Belavadi Post, Mysore, Pin , Karnataka, India. Sales Offices Delhi Zensar Business Centre N-83, 1st Floor (Above PNB), Connaught Place, New Delhi , India. Tel. : Fax : Kolkata Halwasiya Mansion, Ground Floor, 6/2, Moira Street, Kolkata , India. Tel. : Fax : Mumbai 6th Floor, RPG House, 463. Dr. Annie Besant Road, Worli, Mumbai , India. Tel. : , Fax : Vadodara A-304, Siddhi Vinayak Complex, Faramji Compound, Bh. Rly. Station, Alkapuri, Vadodara , India. Tel. : Fax : Pune Flat No.9, KSHITIJ,1 st Floor, 769/6, Lane No.7, Prabhat Road, Deccan Gymkhana, Pune , India. Tel. : , 6065 Fax : Hyderabad 406 & 407, Maheshwari Chambers, Erramanzil, Somajiguda, Hyderabad , India. Tel. : Fax : Chennai Bhavani Mansion No.3, 4th Lane, Nungambakkam High Road, Chennai , India. Tel. : , Fax : Bangalore C/o. CEAT Limited, Jasmine Mansion, 4th Floor, 19, J. C. Road, Bangalore , India. Tel. : Fax : July 2011 MANGALAM M :