21.External Plant
Contents
1. Advantages of Drop wire Drop wires Self Supporting Dia of Cdr 1 25mm and 0 91 mm Nowadays 0 51 mm DW are supplied Accessories used for Drop Wire 1 Support Clamp with U Back Can be fitted onto the bracket and can take 2 distribution Clamps 2 Drop wire Distribution Clamp Made up of Reinforced Plastic Material Thro this only DW will be taken No friction Rubbing of DW Distance between 2 support calmps on a Bracket 20 cm DW Joint should be done at a Fixture here 2 distribution clamps are used for one DW Jt so that the Loose ends of DW to Be jointed are not strained by span lengh On suspension of DW One Distribution Clamp is used for one DW POLELESS NETWORK What is Poleless and What is the size of cable used for this purpose 5 pair into the Subs Premises 5 pr cable is to be laid at Right angle 90 degrees to the Distribution cable Cemented portion at Subs premises to be chipped for 6 inches depth and 2 inches width cable will be laid inside 1 PVC pipe and then cement concreted For tap joint only 3 inches of Distribution cable is to be remove and correct pair to be tapped leaving the other pairs undisturbed 25 mm PVC Water pipe is to be used for bringing the 5 pr from Ground to the wall mounted DP at a Height of 140 cm Number of pairs to be tapped from Distribution cable 1 For one connection One Pair only 2 For 2 connections in a building 2 1 3 pairs 3 For 3 4 connections in Building 5 pairs 4 More than 4 C2. No 88 is available at 9 module from the top and 8th cct from Left Position and Counting Of CT Boxes POV DNB 3 B2 renien El E2 Ex D2 CT Box 4 th Row from the top and 2 nd Ct box from Left E1 CT Box 5 th Row 1 st from left Jumpering will be done only thro Jumper Rings Cabinets are numbered from 01 20 Pillars are numbered from 21 99 Nowadays since there is no use of cabinets Pillars are numbered from 01 99 Main features of Krone Tool and usage of parts The Inner Zone area is covered by a radius of 500 metres from Xge Here there will be NO pillars DPs are directly erected from MDF Rigid System of Cable Planning Less than 500 lines xge Cable section is from MDF to DP No Pillars in between Flexible system of Planning More than 500 Lines Here Pillars are introduced in between MDF amp DP DPs Type External DP 10 20 pair Internal DP Wall mounting 5 pr Dp PoleLess Minimum Height of Ext DP 9 Feet 27 28 29 30 31 32 Internal DP 8 Feet Wall mounting 140 cm 4 to 5 Feet DPs Numbering 4 Digits Ex 7707 The first 2 digits 77 represents the Pillar NO from which DP is working Next 2 digits 07 is Serial No of DP Inner Zone DPs starts with 00 Ex 0012 00 Inner Zone 12 Serial NO of DP DP Clamps Used at 3 places in a DP post to hold the DP post and GI pipe together Bottom Middle and Top Explain DP Dressing and Rehabilitation of DP Advantages and Dis advantages of Pillar System In a 1000 pr Pillar E
3. Quad 4 Conductors are twisted in a single operation in such a way that conductors forming one pair is opposite to each other to avoid X Talk PIJF COLOUR CODE In a 20 pr PIJF the Mate colours used are White Mate Pairs 1 5 Red Mate 6 10 Black Mate 11 15 and Yellow Mate 16 20 Colour Code Pair No 18 in a 20 pair Yellow Green 50 Pair 5x 10 pair Units Colour Binder for Unit No 1 Blue 1 10 2 Orange 11 20 3 Green 21 30 4 Brown 31 40 5 Slate Grey 41 50 100 Pair 5 X 20 pair Units Unit No 1 Blue 1 20 2 Orange 21 40 3 Green 41 60 4 Brown 61 80 5 Slate Grey 81 100 200 pair 4 Super Units x 50 pair 400pair 8 Super Units x 50 pair 20 21 22 Colour Binder For Super Units First SU Marker RED Binder Last SU Reference BLACK Intermediate WHITE Binder More Than 400pair cables are divided into 100 pair SU 800 8 SU x 10 pair 2400 24 SU x 100 pair Pair Gain systems are introduced in Local Network to provide Temporary relief to TNF Technically Not Feasible Areas where Cable Pair Scarcity is there Advantages of PIJF cable PCM Coaxial PCM cables were used for JUNCTION working Sizes of PCM Cable 10 2 0 63mm 20 4 48 6 and 96 8 The Diameter of Conductor of PCM Cable is 0 63 mm only The Aluminium Screening bisecting the Cable Core in PCM GO pair and RETURN Pair of a system will be Loaded on either side of Screening to avoid X talk Co axial Cables were used for LONG DISTANCE NETWORK Typ
4. External Plant and Access Network OBJECTIVE TYPE QUESTIONS UNDERGROUND CABLES TYPES The conductors used in UG cables High Conductivity Annealed copper conductors with round shape The Diameter of CU conductors used in UG Cables 0 40 mm 0 51mm 0 63 mm 0 90mm The Types of Insulation a Paper LSDC and Composite Sheathed Cable b Polythene In PIJF cables Purpose of Insulation a To insulate Physical separation and Electrical Separation between Cu conductors b For colour code Identification of Cable pairs The lay and overlapping of cable pairs are so chosen to To satisfy capacitance unbalance requirements and to prevent X Talk In PIJF cable the Moisture Barrier used is Petroleum Jelly In LSDC Lead Sheathed Dry Core Cable The Insulation is Paper The Sheath is Lead In PIJF Polythene Insulated Jelly Filled The Insulation is Polythene The Sheath is POLY AL The Mechanical protection in UG Cable 2 Layers of Steel GI Strips known as ARMOURED cable Cable Without Steel Tapes are Unarmoured Cables To be used in DUCT Laying Primary sizes The Higher Dia Conductor gt 0 51mm is used for Long Distance Lines 15 16 Paper Insulated Cables PCUT Paper Core Unit Twin used for Local Subscriber Network PCQL Paper Core Quad Local Used for Junction Network between 2 Exchanges minimum Dia 0 63mm PCQT Paper Core Quad Trunk used for Trunk Circuits Minimum Dia 0 63 mm PCQC Paper Core Quad Carrier Used For Carrier Circuits
5. als are available CT Box sizes 50 pair 100 pair Single Inlet Double Inlet type Types of CT Box wiring A Type Single Inlet CT Boxes are used Ct Box will be terminated either with Xge side or DP side Cables only B Type Double Inlet CT boxes are used EX In a 100 pr Double Inlet CT box 50 pr Left side is for Xge side cable and 50 pair Right DP side cable Exge side terminals and DP side terminals appear side by side No Jumpering required Metal Strap will be provided from Xge side to DP side C Type Wiring 100 pr Double Inet will take 100 pr xge side and 100 pr DP side Alternate 5 pairs on xge side and DP side will be thro Connected at the Bottom of Pillar and remaing pairs will be terminated on CT boxes Here also Metal Straps will be provided C Type Tip Jointing C Type CT box can be converted into A Type by Tip Jointing the Exge side cable Tail Krone Type CT Boxes Here a CT box is terminated either with Xge Side or with DP side 19 20 21 22 23 24 25 26 cables only Hence A Type wiring only in Krone CT Boxes In Krone type CT box cables are terminated with KRONE TOOL LSA PLUS Tool NO stripping of wire NO termination and NO Soldering IN Krone CT Boxes the counting of circuits is from Top to Bottom and from Left to Right In Krone CT Boxes the permanent Cable wiring is done on Top side of the Module The Jumpering is done at the Bottom side of the module In Krone CT box pair
6. ate Joints at Manhole Standard size of Drum is around 200 m for Big Size cables Joints will be placed on Support Frames on Side walls of Manhole and NOT On the Bottom Bed of Manhole in which case the Joint will be damaged Planning Period of Ductis 20 years
7. ation Tapes 7 Thermo Shrink Sheet with Metal Iron Channel 8 Branch Clips 9 Mastic Adhesive Black tape for sealing at ends 10 Plastic Cover Sheet while cleaning and placing Filling Compound While inserting the wires into UY Connectors the wires should reach upto the Top Head of the Button The Sheath earth Continuity must be given on Aluminiam Foil of Inner Sheath to prevent damages due to Lightning Extrea High Voltages Modified Blow Lamp Gas Torch with Yellow Flame to be used for heating TSF sheet Heating to be started from centre and proceeded towards one end No Air Bubbles to be present The sheet should be heated till such time the Green Dots available on the sheet just disappears DUCTED CABLE SYSTEM Advantages Ducted system Unarmoured DUCT cables only to be used in Ducted system Diameter of pipes PVC pipes of 4 Dia 102 mm to 105 mm This will accommodate maximum size of primary cable The number of pipes foreach rowis 4 Types of Ducting Sand Filled Ducting Concrete Filled Ducting 4 mm Nylon ropes to be drawn in PVC pipes 10 11 The Depyh of the Top Most pipe is 60 cm on Foot Path and 80 cm in Traffic roads The Types of Manholes 1 Straight Manhole A Manhole 2 Turning Manhole L Manhole 3 Branching Manhole T manhole Facilities to be provided in Man holes Maximum size of Duct Nest 48 Way 12 Rows X 4 Pipes The Distance between 2 Consecutive Manholes is 190 195 metres so as to accommod
8. es and Sizes of Coaxial 174 Coaxial Small Tube 2 Core 4 Core 375 Coaxial Large Tube 2 Core 4 Core 174 CXL means The Inner Diameter of outer CU Tube is 0 174 inches Similarly for 375 also In CXL Interstice Quads Pairs with Cdr Dia of 0 9 mm is available for INTERSTICE Working Polythene Discs placed at Uniform Intervels of 2 inches apart separates the Inner Solid Conductor and Outer CU Tube in CXL Cables CABLE LAYING Depth of Local Cable Trench 100 cm 3 3 Width 30cm T Horizontal Separation between Telecom Cable and Power Cable Not Less than 60 cm The Angle of crossing of Telecom amd Power cable is 90 degrees At crossing with Power cables the Telecom cable should be Laid SOLID with BITUMEN for 90 cm on either side Methods of Cable Laying a Laying Direct Burial by excavating Trench b Solid Laying Bitumen Concrete c Duct Laying PVC Duct Nest amp Unarmoured Cables At Road Crossings use RCC pipe GI At Bridge Culverts GI pipe with cement Concrete At Railway Crossing CI Cast Iron Pipe GI Where Solid Laying is done 1 Inadequate clearance between power cable and Telecom cable Bitumen Solid Laying 2 At the Leading in Leading Out points of Bridge Culverts With GI pipe and Cement Concrete In case of Road cutting Permission ids denied Thrust Boring Sideways Boring to be adopted to negotiate the road Placing of Warning Bricks For one cable Longitudinally 4 4 Bricks per metre Mo
9. onnections 10 pair Intl DP APLAB DIGITAL CABLE FAULT LOCATOR 3039 General Types of Cable Faults 1 Earth Fault 10 11 12 Low Insulation Fault Break Disconnection Short Loop Foreign Potential a A WwW N 6 Dry Joint Corrission Basic Requirements of Detection and Localization of Faults Refer 2 1 at Page 161 What is the voltage of Insulation Megger 100 volts Principle of working of Aplab Locator Pulse Echo method Pulse Reflection Method What are the functions of various Knobs swiches Refer page 164 amp 165 Purpose of Horizontal position knob Controlling Left to Right Horizontal Movement of Curve Pulses Vertical Position Contrlling UP and Down Movement of pulses Horizontal Expansion Expanding the pulse Curve along X axis to have an accurate Display Vertical Gain Controls the vertical amplification of the pulse to have a puse of sufficient height The Fault pair is connected to L1 Terminal The Good Reference pair is connected to L2 Terminal If Required How many Ranges are available 0 0 3 KM range Both buttons not pressed 0 1 Km Range First button pressed Il Button NOT Pressed 0 3 Km range Button Not Pressed II button Pressed 0 10 KM Range Both Buttons Pressed What is the power Supply 12 15 Volts Nickal Cadmium Batteries External DC also can be connected The V 2 Constant is different for different types of cable V 2 is selected thro Velocity Selector a Thumb Wheel S
10. re than one cable Transversely 10 11 12 13 14 What are the steps involved in Cable Laying 1 Survey of Cable route Decide the side of the road Marking of Cable Trench Excavation of Cable Trench as per the standards Inspection Cable Trench for its Depth and Alignment Approval of Trench for Laying Cable N OORA W PY Laying of Cable as per standards Use Cable Rollers inside Trench 8 Placing of Warning Bricks 9 Closing Cable Trench 10 Ramming Of Cable Trench 11 Making Cable History with Route Index Digaram What is Dial before Dig service What is the use of Flooding of Cable Trench Shortest Cable Route must be selected The Arrow mark on Cable drum denotes the Direction of Rotation of the Drum CABINETS PILLARS amp DPs Cabinets Pillars are Partial Flexible Points Sizes of Cabinets Pillars Old Type Not used now 300 pr 500 700 1000 1400 pairs Sizes of Krone Type Pillars Used now 800 pairs 1000 1600 and 2000 pairs Old Type Cable from Exge MDF to Cabinet Primary Cabinet to Pillar Secondary Pillar to DP Distribution Krone Type Pillars No Cabinets are used now Cable from Exge MDF to Pillar Primary Pillar to DP Distribution CT Boxes are Cable Terminal Boxes where Cables either from xge or Cables to DPs are terminated Exge side CT Box Primary cable is terminated DP side CT Box Distribution cables are terminated Conventional Type CT Boxes Not used now Screw Type Termin
11. to be used Here 20 pairs are arranged in a Modular strip colour code wise and they are jointed in a Single Compression of Modular Tool EX For 400 pr Joint 20 No of 20 pr strips are reqd along with Compression Tool The UY connectors CAN NOT be used on Paper Cables Plumbers Metal Lead is used for wiping and sealing in Lead Sleeve Technique LSDC Cables and CXL cables IN ALSS plumbing Technique The Main Sleeve used is 1 Auxiliary Sleeves are 2 The Main Sleeve is Plumbed over the Auxiliary Sleeves Various sizes of TSF Kits for PIJF TRO 1 PSF 2 dacitusenisuapideaceanies TSF 7 Which Kit to be used on which size cable Refer Book Ex TSF 1 20 51 20 63 TSF 2 20 9 50 63 TSF 7 More than 800 51 PIJF What is TSR Thermo Shrink RE Entry Kit while attending Faults Tools used in XAGA Technique 1 Crimping Tool for conductor jointing 2 Modified Blow Lamp or Gas Torch Yellow flame with Moderate Temperature to be used for heating the Thermo Shrink Sheet What is the purpose of Aluminium Cannister 1 To give round shape to yhe Joint 2 TSF sheet will have more Grip and adhesiveness over Cannister 3 To some extent it gives Mechanical Strength Mention some Items in TSF KIT 1 CTC Carbon Tetrea chloride Liquid for cleaning 2 Cable Filling Compound Jelly 3 Sheath Continuity CU wires with Crocodile Clips at the ends 4 Emery Sheets for rubbing on the Cannister and Sheath 5 Metal Aluminium Cannister 6 Insul
12. witch 16 17 18 20 21 V 2 Constants 1 Paper Insulated 104 2 Jelly Filled 88 3 PVC 82 The Meter should Be earthed at Earth Terminal If the Battery is LOW RED LED will Glow Low Battery Display The Break Fault Open CCT is denoted by the pulse with UPWARD Projection The Short Loop Fault is denoted by DOWNWARD Projection The pattern of the Original Transmitted Pulse is BREAK The FOOT of the Original T pulse and the FOOT of the REFLECTED Pulse FAULTY PAIR should be synchronised Press the READ Button The Distance to the Fault is displayed CABLE JOINTS What is straight Joint Ex 100 pr to 100 pr What is Branch Joint Ex 800 pair to 2 NOS of 400 pr Jointing Closure Techniques used 1 Lead Sleeve Plumbing Technique LSDC cable 2 ALSS Auxiliary Lead Sleeve Composite sheathed 3 XAGA 250 technique PIJF cables Thermo Shrink Filled Kits are used Conductor Jointing Paper Insulated Cable Conductors are jointed thru TWIST method with correct size PAPER SLEEVES 2 Paper sleeves are required for one pair Here the Insulation to be removed Conductors Twisted Jointed and if Reqd Soldered More than 0 51 mm PIJF For jointing the pairs UY CONNECTORS B Connectors Buttons are used 2 Buttons are reqd for one pair CRIMPING TOOL alone to be used splicing Here NO removal of Insulation NO Jointing and NO soldering For Higher size PIJF cables gt 200 pairs MODULAR CONNECTOR 20 Pair Strips are
13. xchange side Primary pairs 400 pr 4 CT Boxes DP side Distributon pairs 600 pairs 6 CT boxes CABLE RECORDS Maintenance of Cable records will help in Discovering and Localizing Cable faults and for Rehabilitation of Cable Network Mention cable records to be Maintained 1 Town Plan Town Map Exchange Area lay out Map Primary Secondary Cable Diagram Single Diagram Cabinet Pillar Lay out Pillar Diagrams For each pillar separate Diagram Junction Cable Diagram N OORA W PP Line Route index Diagram for primary Secondary and Distribution Cables mentioning Route Joint Locations geographically Mention the Cards to be Maintained 1 MDF Card Tag Block wise 11 12 2 Pillar Card CT Box wise 3 DP cards 4 Subscriber Index Cards 5 Repeated Fault Card What is Dial Before Dig Service IN MDF Counting is always from Bottom to Top MDF verticals are numbered from 01 99 from Non Growing end Tag Blocks Connection strips are numberd from 00 09 from Bottom to top Ex 157 22 15 th vertical Tag block No 7 and CCT No 22 What is CRMS Cable Records Management System What are the benefitsof CRMS Refer Book What is FRS Fault Repair Service Manual FRS Computerized FRS and DOT Soft FRS While attending the Faults The Lineman Should Go to the Subscriber Premises FIRST Action to be taken on Repeated Fault Cases What are the advantages of Computerized FRS compared to Manual FRS DROP WIRE
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