CLC TR 50117-8-2013 Coaxial cables used in cabled distribution networks - Part 8 Repair and substitute of damaged buried cables.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationCoaxial cables used in cabled distribution networksPart 8: Repair and substitute of damaged buried cablesPD CLC/TR 50117-8:2013National forewordThis Published Document is the UK

2、implementation of CLC/TR 50117-8:2013.The UK participation in its preparation was entrusted to Technical CommitteeEPL/46, Cables, wires and waveguides, radio frequency connectors and accessories for communication and signalling.A list of organizations represented on this committee can be obtained on

3、request to its secretary.This publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application. The British Standards Institution 2013Published by BSI Standards Limited 2013ISBN 978 0 580 80756 5ICS 33.120.10Compliance with a Britis

4、h Standard cannot confer immunity fromlegal obligations.This Published Document was published under the authority of theStandards Policy and Strategy Committee on 30 April 2013.Amendments issued since publicationAmd. No. Date Text affectedPUBLISHED DOCUMENTPD CLC/TR 50117-8:2013TECHNICAL REPORT CLC/

5、TR 50117-8 RAPPORT TECHNIQUE TECHNISCHER BERICHT March 2013 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All right

6、s of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. CLC/TR 50117-8:2013 E ICS 33.120.10 English version Coaxial cables used in cabled distribution networks - Part 8: Repair and substitute of damaged buried cables Cbles coaxiaux pour rseaux cbls de distribu

7、tion - Partie 8: Rparation et remplacement de cbles coaxiaux souterrain Koaxialkabel fr Kabelverteilanlagen - Teil 8: Reparatur und Ersatz beschdigter Koaxialkabel This Technical Report was approved by CENELEC on 2013-02-26. CENELEC members are the national electrotechnical committees of Austria, Be

8、lgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Swed

9、en, Switzerland, Turkey and the United Kingdom. PD CLC/TR 50117-8:2013CLC/TR 50117-8:2013 2 Contents Page Foreword . 4 1 Scope . 5 2 Normative References . 5 3 Terms and definitions 6 4 Coaxial cables 6 4.1 Construction of coaxial cables . 6 4.2 Long term behaviour and asset of coaxial underground c

10、ables . 6 5 Laying of underground cables 6 5.1 General 6 5.2 Laying in the sand bed . 7 5.3 Laying in ducts 7 5.4 Laying in a duct system 7 5.5 Laying in the conduit 7 6 Effects of damage . 7 6.1 General 7 6.2 Repair 7 6.3 Influence to electric characteristics 8 7 Types of errors . 9 7.1 General 9 7

11、.2 Transection without stretching (shearing, cutting) 9 7.3 Disruption / cable elongation with impact on indefinite length 9 7.4 Strain / elongation without tearing effect with an indefinite length of cable. 9 7.5 Other damage with selective or limited local impact . 9 7.5.1 General 9 7.5.2 Deformat

12、ion without stretching, such as squeezing, compressing, dropping below the minimum bending radius 9 7.5.3 Damage to the outer sheath by fire or heat . 9 7.5.4 Slightly damaged cable sheath without deformation of the outer conductors . 10 8 Failure analysis and repair . 10 8.1 General 10 8.2 Fundamen

13、tal distinction of occurring damage and its repair 10 8.2.1 General 10 8.2.2 Cable was not elongated 11 8.2.4 Cable was deformed 11 8.2.5 Jacket was damaged . 11 8.2.6 Outer conductor has transverse cracks 11 8.2.7 Screening effectiveness otherwise affected . 12 8.2.8 Inner conductor looks out from

14、the cable ends 12 8.2.9 Diameter of inner and outer conductor within the specified limits . 12 8.2.10 Effects of tensile forces to remote components 12 8.2.11 Measures for damaged cables with 60 - Ohm impedance . 12 8.2.12 Repairs due to other influences . 12 9 Attenuation of cable joints and connec

15、tors . 12 PD CLC/TR 50117-8:2013 3 CLC/TR 50117-8:2013 10 Use of materials and correct handling . 13 10.1 General 13 10.2 Proper processing . 13 11 Documentation . 14 12 Measurement evidence . 14 12.1 Measuring of power levels 14 12.2 Measuring of reflexion 14 12.3 Measuring of radiated power . 14 1

16、2.4 Measuring of Bit Error Rate (BER) . 14 Annex A (informative) Theoretical Background . 15 A.1 Physical background and Characteristics / parameters for coaxial cable 15 A.2 Reflection coefficient 16 A.3 Return loss . 16 A.4 Pulse return loss . 17 Annex B (informative) Examples of damage . 19 Bibli

17、ography . 23 Figure 1 Construction of a coaxial cable . 6 Figure A.1 Coaxial cables . 15 Figure A.2 Schematic depiction for measuring the return loss . 17 Figure A.3 Composition of the test device for measuring the pulse reflection 18 Figure B.1 Typical damage by laying new paths across the cable pa

18、th . 19 Figure B.2 Underground cable repair of a selectively damaged cable without elongation . 19 Figure B.3 Effect of tensile forces: building entry pulled out of the brickwork, the basement conduit installation ripped out of wall 20 Figure B.4 Selectively damaged cable: sheath peeled off . 20 Fig

19、ure B.5 Cable cut by blade 20 Figure B.6 Torn underground cables . 21 Figure B.7 Damaged cable by tension forces, inner conductor torned. 21 Figure B.8 Perforated screening by pulling forces: Screening effectiveness drastically reduced 21 Figure B.9 Inside of the perforated screening foil by elongat

20、ion of the coaxial cable shielding . 22 PD CLC/TR 50117-8:2013CLC/TR 50117-8:2013 4 Foreword This document (CLC/TR 50117-8:2013) has been prepared by CLC/SC 46XA “Coaxial cables“. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CE

21、NELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. EN 50117 is divided into the following parts: EN 50117-1, Coaxial cables Part 1: Generic specification EN 50117-2-1, Coaxial cables Part 2-1: Sectional specification for cables used in cabled distribution n

22、etworks Indoor drop cables for systems operating at 5 MHz - 1 000 MHz EN 50117-2-2, Coaxial cables Part 2-2: Sectional specification for cables used in cabled distribution networks Outdoor drop cables for systems operating at 5 MHz - 1 000 MHz EN 50117-2-3, Coaxial cables Part 2-3: Sectional specifi

23、cation for cables used in cabled distribution networks Distribution and trunk cables for systems operating at 5 MHz - 1 000 MHz EN 50117-2-4, Coaxial cables Part 2-4: Sectional specification for cables used in cabled distribution networks Indoor drop cables for systems operating at 5 MHz - 3 000 MHz

24、 EN 50117-2-5, Coaxial cables Part 2-5: Sectional specification for cables used in cabled distribution networks Outdoor drop cables for systems operating at 5 MHz - 3 000 MHz EN 50117-3-1, Coaxial cables Part 3-1: Sectional specifications for cables used in Telecom applications Miniaturized cables u

25、sed in digital communication systems EN 50117-4-1, Coaxial cables Part 4-1: Sectional specification for cables for BCT cabling in accordance with EN 50173 Indoor drop cables for systems operating at 5 MHz - 3 000 MHz EN 50117-5, Coaxial cables used in cabled distribution networks Part 5: Sectional s

26、pecification for indoor drop cables for use in networks operating at frequencies between 5 MHz and 2150 MHz EN 50117-6, Coaxial cables used in cabled distribution networks Part 6: Sectional specification for outdoor drop cables for use in networks operating at frequencies between 5 MHz and 2150 MHz

27、CLC/TR 50117-8, Coaxial cables used in cabled distribution networks Part 8 Repair and substitute of damaged buried cables PD CLC/TR 50117-8:2013 5 CLC/TR 50117-8:2013 1 Scope This Technical Report describes the procedure to repair damaged CATV cables. The following coaxial cables are considered in t

28、his guide: Coaxial cables with semi air spaced dielectric Outer conductor: copper band, longitudinal welded Coaxial cables foamed polyethylene or solid polyethylene dielectric Outer conductor: copper band, longitudinal welded Coaxial cables foamed polyethylene or solid polyethylene dielectric Outer

29、conductor: Overlapped foil of copper or aluminium with braid Coaxial cables foamed polyethylene or solid polyethylene dielectric Outer conductor: Overlapped foil of copper or aluminium without braid Coaxial cables foamed polyethylene dielectric Outer conductor: Corrugated copper This guide is a help

30、ful tool for providers and installers to find out the extend and the effects of damaged cables and to achieve and to evaluate appropriate repair operation. For not buried cables, e.g. indoor cables, the application of this guide is analogous. NOTE The kind respectively the material of the cable shea

31、th makes the coaxial cable an “underground“ cable. In the underground area the cable jacket determines the long term behaviour of the cable significantly. For this purpose, only plastics with a high long-term stability are used, usually polyethylene (PE). This material provides protection against in

32、gress of water or water-diffusion with good mechanical properties. 2 Normative References The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references,

33、 the latest edition of the referenced document (including any amendments) applies. EN 50117 (series), Coaxial cables EN 50117-1:2002, Coaxial cables Part 1: Generic specification EN 50290-1-2:2004, Communication cables Part 1-2: Definitions EN 50290-4-2, Communication cables Part 4-2: General consid

34、erations for the use of cables Guide to use EN 60728-1, Cable networks for television signals, sound signals and interactive services Part 1: System performance of forward paths (IEC 60728-1) EN 60728-1-1, Cable networks for television signals, sound signals and interactive services Part 1-1: RF cab

35、ling for two way home networks (IEC 60728-1-1) IEC 61196-1-108, Coaxial communication cables Part 1-108: Electrical test methods Test for characteristic impedance, phase and group delay, electrical length and propagation velocity IEC 61196-1-112, Coaxial communication cables Part 1-112: Electrical t

36、est methods Test for return loss (uniformity of impedance) IEC 61196-1-115, Coaxial communication cables Part 1-115: Electrical test methods Test for regularity of impedance (pulse/step function return loss) PD CLC/TR 50117-8:2013CLC/TR 50117-8:2013 6 3 Terms and definitions For the purposes of this

37、 document the terms and definitions given in EN 50117-1:2002 and in EN 50290-1-2:2004 apply. 4 Coaxial cables 4.1 Construction of coaxial cables Innercondutor dOuter conductor D+dGInsulation D Outer sheeth ODFigure 1 Construction of a coaxial cable Coaxial cables (Figure 1) consist of an inner condu

38、ctor, the dielectric and an overlying outer conductor. The structure is protected by a plastic sheath. The outer conductor also acts as a shield against radiation and electromagnetic fields. The outer conductor respectively the screen may consist of a single braid, or a combination of metal bonded s

39、heets and braids. The shielding characteristics are determined by the construction of the screen and the optical coverage. Optimal shielding effect is achieved by cables with a continuously closed metal tube, which for example, is often used in case of buried cables for cabled TV distribution. Coaxi

40、al cable for direct burial can also be provided with other elements, such as intermediate sheaths or moisture barriers. 4.2 Long term behaviour and asset of coaxial underground cables High-quality underground cables are of good long-term stability. They are most durable and without loss of quality.

41、Good example for the high durability are the CATV cable types ikx, nkx, qkx and skx. These cables have a cable sheath of PE and fulfil to date the demands on the transmission characteristics according to the applicable standards for the transmission characteristics, even after 25 years and more of u

42、se. Today, these cables are also used for the transfer of the so-called “Triple Play“ services; that means, additional to the digital transmission of radio and television signals the transmission of signals for Internet access services and telephony services using Voice over IP. By means of digital

43、transmission methods, conventional coaxial cables offer transmission bit rate of the high Gigabit range. Only fibre optic cable offers a higher transmission power. The laid underground cables are thus a valuable and lasting transmission resource, one of the business basics of cable operators. This a

44、pplies regardless of the age of cable laid, as the transmission performance does not deteriorate, except in case of damage of the cable. 5 Laying of underground cables 5.1 General For general hints for laying, see EN 50290-4-2. PD CLC/TR 50117-8:2013 7 CLC/TR 50117-8:2013 5.2 Laying in the sand bed

45、Typically, the cables are laid in the sand bed in a cable trench. The sand bed provides protection against damage by stones and dissipates the weight of the overlying ground, under the best possible protection of the cable. The so-called Warning tape marked “Caution Cable”, or “Cable Television“ abo

46、ve the laid cable in the sand bed is supposed to draw attention to possible earthworks on the underground cables underneath. 5.3 Laying in ducts Basically it is the same installation technology as in the laying of cables in the sand bed. However, instead of a cable, a conduit is laid, through which

47、the cable is pulled or blown after laying the conduit. Laying in ducts is also possible, with the so-called “Press to move procedure“ (Pressverfahren), whereby a drive head, driven by compressed air produces an underground channel. In this channel, a conduit is pushed where finally the cable is blow

48、n or pulled. There are other procedures in which the conduit is injected or otherwise introduced into the earth. Since at the latter procedure not a cable trench is made, there is no Warning Tape. Nevertheless, such laid cables can be located with appropriate cable fault location systems. 5.4 Laying

49、 in a duct system Duct systems consist of bundles of pipes of installed cables or cable ducts with “cable stones” (Kabelsteine) in certain intervals. The cables are placed in the respective tube. 5.5 Laying in the conduit Laying in the conduit is done by install conduits, or cable trays etc. In the event of damage procedures described in this guide apply accordingly. 6 Effects of damage 6.1 General Coaxial cables are se