1、R 48b2591 Ob7037 Ob4 W INTERNATIONAL TELECOMMUNICATION UNION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE OUTSIDE PLANT TECHNOLOGIES FOR PUBLIC NETWORKS Geneva, 1991 - U862591 0678038 TTO o ITU 1991 Ail rights reserved. No part of this publication may be reproduced or utili
2、zed in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. INTERNATIONAL TELECOMMUNICATION UNION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE OUTSIDE PLANT TECHNOLOGIES FOR PUBLIC NETWORKS Gen
3、eva, 1991 4862573 Ob78040 b5 o ITU 1991 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 4862593 Db7804L 595 TABLE OF CONTENTS Page -
4、1 -. 1 . PART I . BASIC INFORMATION ABOUT THE CONSTRUCTION OF TELECOMMUNICATION CABLES . CHAPTER 1 . BASIC INFORMATION ABOUT THE USAGE OF TELECOMMUNICATION CABLES . Introduction 1 2 3 4 5 General Cable - Characterized by service function . 2.1 Trunk and junction 2.2 Main cables 2.3 Distribution cab1
5、 es Cable - Characterized by supporting structure . 3.1 Ducts 3.2 Aerial . 3.3 Direct buried . 3.4 Underwater . 3.5 Building (indoor) 3.6 Cable tunnel . Cable - Environment . 4.1 Duct cables . 4.2 Aerial cables . 4.3 Buried cables 4.4 Building cables and wires . 4.5 Open wire . 4.6 Subscriber connec
6、tion wire . 4.7 Cable tunnel cables . Cablestructure design considerations 5.1 Underground systems 5.2 Pole lines 5.3 Buried consauction . Table of Contents 1 3 3 3 4 4 4 5 5 5 5 5 5 5 6 6 6 6 6 III Page 5.4 Buildings 7 . 5.5 Cable tunnels 7 7 7 Cable size 7 8 Conductor size . 7 6 Cable types - Gene
7、ral CHAPTER 2 - BASIC MATERIALS TO BE USED FOR THE CONSTRUCTION OF TELECOM- MUNICATION CABLES 9 1 Basic materials to be used for the construction of telecommunication cables . 9 2 Metals 9 2.1 Copper 9 2.3 Lead and its alloys 11 2.2 Aluminium . 10 2.4 Steel . 13 2.4.2.1 Hot-dip zinc-coated (HDZC) st
8、eel tape . 13 2.4.2.2 Sendzimir process zinc-coated (SEZC) steel tape . 14 3 Plastics 16 3.1 Plastic insulation materials . 16 3.1.1 Polyolefms . 16 3.1.2 Cellular or foam/skin . 16 3.1.3 Polyvinyl chloride (PVC) . 17 3.2 Plastic sheath materials . 17 3.2.1 Fire retardancy of plastic sheath material
9、.,. 17 4 Paper . 18 . 5 Compounds for impregnating and coating the external protection of metallic sheaths and armourings . 18 5.1 Compound characteristics . 18 5.2 Properties 20 CHAFER 3 - THE BASIC ELEMENTS USED IN TELECOMMUNICATION CABLES 21 1 Conductors 21 1.1 Copper 1 . 21 1.2 Aluminium . 22 1.
10、3 Special conductor materials 22 .- IV Table of Contents 48b259L Ob78043 368 II Page 2 Symmetrical pairs (pair or quad) 22 2.1 Insulation 22 2.1.1 Plastic 23 2.1.2 Pulp . 23 2.1.3 Paper . 23 2.2 Make up 24 2.3 Electrical characteristics . 24 3 Coaxial pair . 27 3.1 Dielectric insulation 27 3.2 Scree
11、ning tapes . 28 3.3 Outer conductor insulation 28 3.4 Electrical characteristics . 28 4 Water blocking of cable core . 28 4.1 Paper or pulp insulation 28 4.2 Embedded cellulose fibres 28 4.3 Continuously filled cable 28 4.4 Discrete water blocks 30 5 Cable core wrapping 31 6 Cable sheath 6.1 Screeni
12、ng 6.2 Metal sheaths 6.2.1 Lead sheath 6.2.2 Aluminium 6.2.3 Steel 6.3 Plastic sheath 6.3.1 Moisture barrier sheath 6.4 Anti corrosion sheath servings 6.5 Termite protection 31 32 32 32 32 33 33 34 36 36 7 Armouring . 36 7.1 Beddings for armoured cable 37 7.2 Steel tape mouring . 37 7.3 Steel tape a
13、rmouring . 37 7.4 Servings for armoured cables 37 8 Sheath combinations 37 Table of Contents V 4862571 067601.i4 2T4 CHAPTER 4 . BASIC TELECOMMUNICATION CABLE CORE AND SHEATH MAKEUPS 39 1 Symmetric pair polyolefin insulated conductor cables . 39 1.1 General . 39 1.2 Cable core construction 39 1.2.1
14、Unit pair and unit quad cables 39 1.2.2 Concentric audio cable 40 1.2.3 Cables for analogue carrier application 40 1.2.4 Cables for digitai transmission with a bit rate of up to 2 Mbit/s 1.2.5 Filling 1.2.6 Wrapping . 2 Coaxial cable . 2.1 General . 2.2 Cable core conswction 0.712.9 mm coaxial pair
15、cable 1.U4.4 mm coaxial pair cable 2.619.5 mm coaxial pair cable 2.2.3.1 Modified coaxial pairs 2.2.4 Wrapping . 2.2.1 2.2.2 2.2.3 3 4 Pulp insulated unit twin cable 3.1 General . 3.2 Cable core construction . 3.2.1 Units for multiple unit pulp (Mup) cables . 3.2.2 Unit lay up . 3.2.3 Wrapping . Sym
16、metric pair paper insulated cables . 4.1 General . 4.2 Cable core construction 4.2.1 Unit twin or quad cables of more than 100 pairs or 100 quads . 4.2.1.1 Sparepairsorquads Cables for andogue carrier application 4.2.2 4.2.3 Wrapping . 5 Cable sheath 5.1 5.2 Plastic shearh without metallic iayer . M
17、etailplastic sheath wirb aluminium tape . 40. 41 42 42 42 42 42 42 42 44 44 44 44 45 45 45 46 48 48 48 48 48 48 48 48 48 49 VI Table of Contenis 4662531 0678045 130 Page 49 5.3 Metaplastic sheath with aluminium tape and tinned-steel ta. 5.4 MetaUplastic bonded sheath with coated aluminium or steel t
18、ape . 49 5.5 MetaUplastic sheath with copper/steel/copper laminated tape . 49 5.6 Metaplastic sheath with welded metal shea tb 49 5.7 Cables of special construction . 49 5.8 Composite sheath consmction 49 6 Special aerial cable consauction 50 6.1 Self-supporting sheath . 50 7 Subscriber connection c
19、ables . 51 7.1 Flat self-supported connection cable . 51 7.2 Round seif-supported connection cable . 51 7.3 Buried connection cable 52 8 Cable sheatb information . 53 8.1 Identification 53 8.2 Length marking 53 Glossary . 54 PART II . INSTALLATION AND ASSEMBLAGE OF TELECOMMUNICATION CABLES AND THEIR
20、 SUPPORTING STRUCTURE 69 CHAJTER 1 . GENERAL RULES FOR THE INSTALLATION AND ASSEMBLAGE OF TELECOM- MUNICATION CABLES IN PUBLIC NETWORKS . 1 Planning considerations . 1.1 General . 1.2 Specific 1.2.1 Assessment 1.2.2 Aboveground versus out-of-sight plant . 1.2.3 Cable design plans . 1.2.3.1 1.2.3.2 1
21、.2.3.3 1.2.3.4 1.2.3.5 1.2.3.6 1.2.3.7 Multiple design . Dedicated outside plant Serving area concept . Unigauge design . Multigauge design Exchange and toll runks Pressurization . Table of Contents 71 71 71 72 72 72 72 72 72 73 73 73 73 73 VXI 4862593 Ob7804b O77 Page 1.2.4 Cable network design and
22、 utilization . 74 1.2.4.1 Structure of the local network 74 1.2.4.2 Main cables 74 1.2.4.3 Underground conduit 74 1.2.4.4 Distribution cable . 74 1.2.4.5 Pole line . 75 2 Planning and design guidelines 75 2.1 Overhead plant . 75 2.2 Direct buried plant 75 2.3 Duct (underground) plant 76 CHAYIER 2 .
23、PRINCIPAL METHODS FOR THE INSTALLATION OF TELECOMMUNICATION CABLES AND THEIR SUPPORTING SU . 77 uiuoduction 77 1 Overhead plant 1.1 General . 1.2 supports 1.2.1 Considerations . 1.2.2 Materials 1.2.3 Wood poles 1.2.3.1 Criteria . 1.2.3.2 Maintenance . 1.2.3.3 Pole classes Supports ConstniCtiOn . i .
24、 1.2.4.1 Ordinary supports . 1.2.4.2 Reinforced supports 1.2.5 Pole strength design . Wires. cables and strands 1.2.4 1.3 1.3.1 Wires and cables 1.3.1.1 insulated wires 1.3.1.2 Self-supporting cables 1.3.1.3 Lashed cables . Suspension strand streng th . 1.3.2.2 Strength calculations 1.4 Aerial cable
25、 instailation 1.4.1 Fastening material . 1.3.2 1.3.2.1 Tension and length . 1.4.1.1 Self-supporting wires 78 78 78 78 78 79 79 79 80 80 80 80 82 83 83 83 83 84 84 84 85 85 85 85 WI Table of Contents 9 4662571 Ob78047 TO3 9 1.4.1.2 Cables 1.4.1.3 Cable sheath continuity 1.4.2 Placiig procedures . 1.4
26、.2.1 Lashed aerial cables 1.4.2.2 Self-supporting cabla 1.5 Earthing provisions . 1.5.1 Classification . 1.5.2 Earthing of cables and strands 1.5.2.1 Wood pole lines 1.5.2.2 Power lines . Construction of earthing points 1.5.3.1 General . 1.5.3.2 Methods 1.5.3 Page 85 87 87 87 89 89 89 89 89 90 90 90
27、 90 2 Direct buried plant . 90 2.1 Cable locations . 90 2.1.1 Urban and suburban residenthi areas . 90 2.1.2 Low-density (rural) areas . i . 90 2.2 Methods 91 2.3 2.4 2.2.1 General 2.2.2 Trenching 2.2.3 Ploughing Primary equipment . 2.3.1 Trenchers . 2.3.2 Ploughs Secondary equipment 2.4.1 Reel carr
28、ier 2.4.2 Cable feed system 91 91 91 92 92 92 93 93 93 2.5 Cable placing 93 2.6 Backfilling and ground restoration 94 3 Duct (underground) plant . 94 3.1 General . 94 3.2 Conduit and pipe . 94 3.2.1 Selection Factors . 94 3.2.2 Duct materials and application . 95 3.2.2.1 Single-way duct unit systems
29、 95 3.2.2.2 Plastic ducts 95 3.2.2.3 Steel ducts 95 3.3 Placement . 95 3.3.1 Duct arrangements . 95 Table of Contents lx E Y6259L Ob78048 9YT 3.3.2 Separation from other structlires 3.3.3 Placing and backfill requirements 3.3.4 Horizontal boring . 3.3.5 Direct buried multiducts 3.3.6 Underwater cond
30、uit . 3.3.6.1 Instaation methods 3.3.6.2 Construction techniques 3.3.7 Checking of ducts 3.4 Manholes 3.4.1 General 3.4.2 Determination of manhole size 3.4.3 Structurai design 3.4.4 Site cast concrete manholes . 3.4.5 Recast concrete manholes . 3.4.6 Covers . 3.4.7 Manhole extension rings 3.4.8 Duct
31、 assignment and cable racking 3.5 Cable installation 3.5.1 General 3.5.2 Precautions 3.5.3 Tools and equipment 3.5.4 Placing methods . 3 S.5 Mechanical aspects 3.5.5.1 Dynamic effects 3 55.2 Pulling force reduction . 3 55.3 Checks and verifications . Page 96 96 96 97 97 97 97 98 98 98 98 99 99 99 99
32、 100 100 100 100 100 101 101 106 106 106 106 CHAPTER 3 . SYMMETRICAL AND COAXIAL PAIRS JOINTING TECHNIQUES . 107 Introduction 107 1 Methods or jointing symmetrical pairs in communication cables . 107 1.1 General . 107 1.1.1 Elecmcal considerations 108 1.2 Manual methods of jointing . 108 1.2.1 Twist
33、 jointing - With and without soldering 108 109 109 1.2.1.1 1.2.1.2 Method of jointing conductors with plastic insulation using plastic sleeves filled with silicone grease or petroleum jelly Method of jointing conductors with plastic insulation by twisting and by means of plastic sleeves welded with
34、the conductor insulation X Table of Contents W 48b2592 Ob78049 8b W 1.2.1.3 1.2.1.4 Meth d of jointing plastic insulated conductors by twisting and insulating with a polyethylene sleeve filled with compound Method of jointing plastic insulated conductors by twisting and insulation with thermo-shrink
35、able sleeves . 1.3 Welding 1.4 Connector jointing Methods using serrated“ metal connectors “Slotted” metal tag connector 1.4.2.2 Singlddiscrete connectors - U type . 1.4.2.3 Pair COMCOTS . 1.4.2.4 Modular connecting systems . Pin and sleeve (PAS) connector . 1.4.1 1.4.2 1.4.2.1 SinglddiSCrete COIUXC
36、S - Butt type 1.4.3 1.4.4 Guillotine COMeCtors . 1.4.5 Connectors for special applications 1.4.5.1 Trim-out connector . 1.4.5.2 Drop-wire connector . 2 Methods of jointing coaxial conductors in communication cables 2.1 General . 2.2 Methods of jointing inner conductors 2.2.1 General 2.2.2 Soldering
37、methods . 2.2.2.1 Without sleeves 2.2.2.2 using sleeves 2.2.2.3 Using thermo-shrinkable sleeves . 2.2.3 Crimping methods . 2.2.4 Methods using threaded sleeve . Restoration of inner conductor insulation 2.3.1 Using original insulation 2.3.2 Using alternative insulation . 2.3.3 Other methods . 2.3 2.
38、4 Methods of jointing outer conductors 2.4.1 General 2.4.2 Soldering methods . 2.4.2.1 Using haif-sleeves 2.4.2.2 Using cylindrical sleeves 2.4.2.3 Using existing outer conductors 2.4.2.4 Using thermo-shrinkable tubing 2.4.4 Mechanical clamping method 2.4.3 Crimping methods . Table of Contents Page
39、109 109 109 110 110 110 110 111 111 111 112 112 113 113 113 113 113 114 114 114 114 114 114 114 114 115 115 115 115 115 115 115 115 115 116 116 116 116 XI 2.5 Methods of screening the Joint 2.5.1 Using original screening tape . 2.5.2 Otermebods . . 2.6 Insulation or sealing of the completed coaxial
40、joint 2.7 Coaxial pair joints . 3 Assessment of conductor joint performance . 3.1 General . 3.2 Functional tests . 3.2.1 Electrical tests . 3.2.1.1 Joint resistance . 3.2.1.2 Dielectric strength 3.2.1.3 Insulation resistance . 3.2.1.4 Crosstaik attenuation 3.2.1.5 impedance irreguiarity 3.2.2 Mechan
41、ical tests 3.2.2.1 Tensile strength 3.2.2.2 Torsion strength 3.2.2.3 Bending strength . 3.3 Accelerate aging tests . 3.3.1 3.3.1.3 3.3.2 Wire joint degradation mechanisms . The main mechanical degradation mechanisms 3.3.1.1 3.3.1.2 The main chemicai degradation mechanisms Table 1m.3 shows jointing m
42、etbods and the most significant joint degradation mechanisms . Test methods . . 3.3.2.1 Oven aging . 3.3.2.2 Temperature cyciing . 3.3.2.3 Current-flow cyciing . 3.3.2.4 Vibration 3.3.2.5 Salt spray and industrial atmosphere . 3.3.2.6 Humidity 3.3.2.7 Stress corrosion cracking References Page 116 11
43、6 116 117 117 117 117 117 117 117 118 118 118 118 118 118 119 119 119 119 119 119 120 121 121 121 122 122 122 122 122 122 CHAFER 4 . METHODS FOR CABU SHEATHS JOINTING . 139 1 Introduction . 139 2 Types of cable sheath 140 2.1 General comments 140 2.2 Type A - Plastic sheath without metallic layer .
44、140 w Table of Contents 9862591 Ob80Sl 434 Page 2.3 2.4 2.5 2.6 2.7 2.8 Classification of joint methods . 3.1 General comments 3.2 Cold processes 3.3 Hot processes Detailed description of processes used in various couniries Type B . Metaplastic sheath with aluminium tape . Type C . MeiaUplastic shea
45、th with aluminium tape and tinned-steel tape . Type D - Metaplastic bonded sheath with coated aluminium strip Type E - Metapiastic sheath with copper/steeVcopper laminated strip Type F - MetaUplastic sheath with welded metal sheath . Cable of special construction 3 4 4.1 Cold processes 4.1.1 4.1.2 M
46、ethod 1 - Processes using plastic tapes, taped joints . Method 2 - Processes using curable cumpounds, pastes, adhesives and resins 4.1.2.1 4.1.2.2 4.1.2.3 4.1.2.4 Method 3 - Processes using mechanical joints . 4.1.3.1 Screw and clamping sleeve without separate end plates 4.1.3.2 Screw and clamping s
47、leeves with end plates . 4.1.3.3 Jointing of sheaths with neoprene sleeves . 4.2 Hot processing Method 1 - Welding of WC cable sheaths with sleeves using heating inserts Method 2 - Processes using injection welding for polyethylene cable sheaths Method 3 - Process using a heat muffle . Method 4 - Pr
48、ocess using thennoshrinkable sleeves 4.2.4.1 Thennoshrinkable joint closures for unpressurized networks 4.2.4.2 Thennoshrinkable joint closures for pressurized networks 4.2.4.3 Thennoshrinkable 2-pair joint 4.2.4.4 Sheath jointing using electrically powered thennoshrinkable sleeve . 4.2.4.5 Sheath j
49、ointing using plastic covers in conjunction with thennoshrinkable sleeves Method 5 - Plumbing of lead closures . Sheath jointing with epoxy-resin paste Jointing of sheaths with plastic tapes or half shells and resin Jointing with plastic half shells bonded together with resin . Jointing of distribution cables using re-openable cap-ended joints 4.1.3 4.2.1 4.2.2 4.2.3 4.2.4 4.2.5 Table of Contents 140 140 140 140 140 141 141 . 141 141 141 142 142 142 143 143 143 147 149 150 150 151 156 157 157 157 159 160 160 162 163 164 164 165 XII1 4862591 Ob78052 370 P
