1. CABLE AND LAYING -B. Prasad Chartered Engineer amieclub@gmail.com

2. Cable cut view 3. TYPE OF CABLE BASEDON CONSTRUCTION Coaxial cable Mineral-insulated copper-clad cable Twinax cable Flexible cables Non-metallic sheathed cable (or nonmetallic building wire, NM, NM- B)[1] Metallic sheathed cable (or armored cable, AC, or BX)[1] Multicore cable (consist of more than one wire and is covered by cable jacket) Shielded cable Single cable (from time to time this name is used for wire) Twisted pair Twisting cable 4. Cable for electrical PVC cable upto 3.3KV XLPE cable upto 33KV LT and HT ABC cable Instrumentation cable Concentric core cable Flexible cable & wire FR/FRLS/LSOH cable Fire survival cable Under water cable 5. Elastomer Trailing cable Locomotive cables Ship wiring cable Wind mill cable/solar cable Welding cable Mining cable LFH cable and wire Fire survival cable EPR, Silicon, EVA cables 6. Telecom PIJF cable 5-2400 pair Indoor telephone cable QUAD/PCM cable Optical fibre cable Armoured/duct/aerial Torpedo cable TOW cable Composite cable 7. Fiber-Optic Cable Advantages: It operate at high speeds It has a large carrying capacity The signals can be transmitted further without being strengthened. It is immune to interference caused by electromagnetic noise such as radios, motors, or other nearby cables. It is cheaper to maintain. You do not have to worry about grounding1 the cable. Disadvantages: The cable is more expensive than copper cables. It is difficult to install. 8. Construction of cable 9. Construction of XLPE 10. Construction of EHV XLPE single core 11. XLPE has replaced conventional cable 12. Insulating material PVC (Polyvinyl Chloride) PE (Polyethylene) XLPE (Cross-Linked Polyethylene) EPR (Ethylene Propylene Rubber) LSF (Low smoke and fume) Polytetrafluoroethylene (PTFE) Thermoplastic Rubber (TPR) Neoprene (Polychloroprene) Styrene Butadiene Rubber (SBR) Silicone Rubber Chlorosulfonated Polyethylene (CSPE) 13. Junction bus 1. Electrical Junction Boxes 2. Wiring Junction Boxes 3. Electric Junction Boxes 4. Plastic Junction Boxes 5. Cable Junction Boxes 6. Plastic Electrical Junction Boxes 7. Weather proof junction boxes 8. Flameproof junction boxes 14. Cable lug Material: copper & aluminium Conductivity : Copper 99.7% iacs Aluminium 61.2% 15. Cable lug ---contd 16. Cable manufacturers Name of manufacturer Brand 1. N.C cable industries National 2. Evershine Electric Works ECKO 3. Electric Cable Industries ECI 4. Paragon Cable Company paragon 5. Surya Power Limited ALCAB 6. National insulated cable co. NICCO 7. Indian cable company INCAB 8. Aluminium industries limited ALIND 9. R.K Electrical KALINGA 10. Polycab Industries POLYCAB 11. Plaza Cable PLAZA 12. Empire Cable Industries EMPIRE 13. Hovels cable HAVELL 14. Cable corporation of India CCI 15. Kei Industries Limited KEI 17. Historical progress of cable technology 18. Historical voltage development in country 19. Indian and international standard 20. Reduction in insulation thickness 21. Metallic sheath 22. Lead sheath construction 23. Electrical Resistivity Material Resistivity (- cm@20 deg.C) Copper 1.724 Aluminium 2.826 Steel 13.8 Lead 21.4 24. Density of material 25. Importance of cable installation A poor installation creates unreliable service other agency my damage the cable. Telephone cable, communication cable, water line, gas pipe line may get affected 26. Location of cabling Laying direct in ground In pipes, Closed or Open ducts, Cable trays and On surface of wall 27. Step of cable installation Route survey Permission Trial pits Pipe laying Material shifting, drum placement Trenching cable laying Bedding and tiling Backfilling Cable installation record tagging 28. Route survey Type of surface like footpath, PCC, RCC, soil type Hazardous like tree roots, pillars, sever line, drain, bus stop, water pipe, gas pipe Cable root passing from private property Cable root away from parallel running gas, water pipe, communication cable etc Road crossing, over bridge, drain crossing 29. Trial pit Along the proposed cable root. Trial pit at the interval of 15-20 meter 30. Permission Before starting the excavation permission to be taken Railways Traffic police and defence Forrest department Communication and gas authority Other service department if any 31. Digging To display Men at work Don't damage the other cable Least use of pickaxe and chisel Correct Depth depending upon voltage grade 32. Depth of cable LT cable (1.1KV) 0.75 m HT cable (11KV) 0.90 m HT cable (33KV) 1.20 m Sand - covered with 150 mm Width of the trench - 350 mm minimum Loop approximate -3 meter each side 33. Minimum bending radius Voltage rating PILC cable PVC & XLPE cable KV Single core Multicore Single core Multicore Upto 1.1 20D 15D 15D 12D 1.1 to 11 20D 15D 15D 15D Above 11 25D 20D 20D 15D 34. Pipe laying if cable crossing the road, gate, railway track, water line Type of pipe: GI, cemented, HDPE pipe Ends to be sealed to avoid choking, clogging. Standard depth of pipe: 1m across the road, 1.8 m across railway track. Standard size of pipe: 1.5 times of cable Spare pipe: for future expansion , Ends to be sealed 35. Bedding Before and after cable laying and jointing work is over a bedding of sieved earth or river bed sand of 100 mm depth both below and above the cable. Keep distance between two cable in single trench. Avoid zig-zag 36. Cable under bed/on support 37. CABLE LAYING IN TRAY 38. Cable laying on rack 39. Tagging on cable 40. Use barricading tape 41. Cable handling 42. Cable handling tools Jack Roller Drum trailer Crimping tool 43. Cable installation record Type of cable and its size Voltage level Cable no, drum no. Date Rout map, location of cable joint Installation test record like IR value, HV test if any 44. Testing of cable installation Insulation resistance test High voltage test Continuity test Value IR value : minimum 1M-ohm/KV HV test value : minimum 1KV/KV +1 for 5 minutes 45. Cable testing Type test Routine test Pre-commissioning test A) for new cable after installation B) After repairing the breakdown 46. Insulation resistance test Before jointing and after jointingS no. Voltage Test voltage New installation Old installation Recorded IR value 1 upto1.1KV 500 V dc for 1 min. 1.0KV dc for 1 min. 50M 2 11KV 1.0KV dc for 1 min. 2.5KV dc for 1 min 200M 3 33KV 2.5KV dc for 1 min. 5.0 KV dc for 1 min. 500M 4 66KV 5.0 KV dc for 1 min. 5.0 KV dc for 1 min. 500M 47. High voltage test value Sr. Voltage level of the cable under test Test voltage Observed leakage current (maximum) New installation Old installation New installation Old installation 1 upto1.1KV 3KV 660V 0.5mA 2mA 2 11KV 18KV 6.5KV 0.5mA 2mA 3 33KV 60KV 19.5KV 0.5mA 2mA 4 66KV 115KV 38KV 0.5mA 2mA 48. Cable testing at manufacturers works a) Tensile Test (For Aluminium Conductor) b) Wrapping Test (For Aluminium Conductor) c) Annealing Test (For Copper Conductor) d) Conductor Resistance Test e) Test for thickness of Insulation & Sheath f) High Voltage Test g) Insulation Resistance Test h) Tensile Strength & Elongation at break test for Insulation and Sheath I) Hot Set Test - (for XLPE Insulation only) j) Partial Discharge test (for H.T. Screened cable) 49. Cable short circuit ISC = kA /t K= Constant Al -- 0.094 (XLPE) Cu -- 0.14382 (XLPE) A - Cross Section Area (mm 2 ) T- Time in seconds 50. Earthing Metal screen (if any) and armour of cable to be earthed. All metal pipes in which cables have been installed need to be earthed. 51. Corrosion Types Encountered With Power Cables Anodic Corrosion (Stray DC Currents) Cathodic Corrosion Galvanic Corrosion Chemical Corrosion AC Corrosion Local Cell Corrosion Other Forms of Corrosion 52. Voltage drop calculation For DC and single phase AC two wire systems Voltage drop = (2xIxLxRxt)/1000 Where I = current in ampere L = length of cable in meter (one conductor only) R = resistance of one conductor from table t = temperature correction factor 53. Voltage drop ----contd For three phase AC systems Voltage drop = (1.732xIxLxRxt)/1000 Note: formula is applied when power factor is unity. Power factor to be considered in load and reactance to be considered. Note: formula is applied when power factor is unity. Power factor to be considered in load and reactance to be considered. 54. Resistance 55. Voltage drop value in% 56. Failure in cable Internal and surface discharge may result failure of the insulation. Proper drying, due to low /bad quality of fluid. Ingress of moisture and degradation of insulation. Crack in the sheath, due to abnormal temperature, electrical stress, mechanical tension. Voids due to partial discharge. Overheating, deformation, ionization etc. NB: permitted size of voids in cable to be 22-25 micron. 57. Root marker Aluminium Cast Iron Material with Standard or Custom design Fibreglass Reinforced Plastic [FRP] 58. Cable tape Size: Length: 5Y, 5m, 10Y, 10m, 20Y, 20m. Width: 12mm, 15mm. 17mm, 18mm, 19mm, 25mm, 48mm, 50mm. 59. Cable gland Type of Cable Gland Size Entry Type/Thread Specification of application Ingress Protection required. Material 60. Parts of gland 61. Type of Gland A1 and A2 Type Cable Gland BW Type Cable Gland CW Type Cable Gland Single Compression Cable Gland Double Compression Cable Gland Flameproof Cable Glands E1W Type Cable Gland Flange Type Cable Gland PG Type Cable Gland Marine Type Cable Gland Metric Threaded Cable Gland Weather Proof Cable Glands 62. Cable ties material Nylon 66 Nylon 66 UV Stabilized Nylon 66 Heat Stabilized Polypropylene Tefzel 63. DIN rail and terminal block 64. De-rating factor Thermal insulation factors Ambient temperature Group factor Depth of laying Thermal resistivity Depth of laying (cm) 75 90 105 120 150 180 Cable size < 25 sqmm 1 0.99 0.98 0.97 0.96 0.95 Cable size < 300 sqmm 1 0.98 0.97 0.96 0.94 0.93 Cable size 300 sqmm 1 0.97 0.96 0.95 0.92 0.91 65. Busbar Material : Aluminium Copper Technical specification Rating Current:3200Amp. System:415Vac, TPN, 50Hz. Fault Level:50KA. For 1 Sec. Operation Temp:40 C rise over 45 C ambient 66. Cable entry Indoor application:Top and bottom both Outdoor application: Only bottom 67. Conduit Fittings & Accessories Construction: Galvanized steel, helically wound, Flexible Conduit System. Temp: -50 C to +200 C Features: Highly Flexible and mechanical strength IP: IP4 68. ACT FAST AND INITIATE FIRST . ---- 69. THANK YOU