IEC TR 60092-370 pdf download – Electrical installations in ships – Part 370: Guidance on the selection of cables for telecommunication and data transfer including radio-frequency cables

IEC TR 60092-370 pdf download – Electrical installations in ships – Part 370: Guidance on the selection of cables for telecommunication and data transfer including radio-frequency cables
1Scope
This Technical Report gives guidance and lays down the basic recommendations for theselection and installation of shipboard and offshore unit cables intended for electrical systemsused in both essential and non-essential analogue or digital signal communication,transmission and control networks，including types suitable for high-frequency signals (i.e.signals with a frequency of more than 105 Hz). These cables are not suitable for directconnection to low impedance supplies. Where such cables are required, attention is drawn toIEC 6o092-353.
Cables intended to have limited circuit integrity (fire resistance) when affected by fire are notcovered by this technical report.
Fibre optical cables are not included.
Sub-sea or umbilical cables are not included.
2Terms and definitions
For the purposes of this document, the terms and definitions given in lEC 60092-350 apply.
3selection of cables
Cables with physical and electrical characteristics in accordance with the IEC 60092 series ofinternational standards are recommended for use in the marine environment.
Cables constructed in accordance with the following standards are acceptable provided thatdue consideration has been given to their use in a marine environment: iEC 60189-1,lEC 60189-2,IEC 60189-3, and IEc 60096-0-1.
4Fundamental considerations
The choice of materials and cable construction should be suitable for the intended applicationand installation of the cable.
The high level of electrical performance associated with many modern cables is only achievedby the accurate,consistent positioning of the various components within the cable.Carelessor excess tension，compression or bending can alter this relationship. This may then havesignificant detrimental effects upon the fundamental performance of the cable at high datarates.
Similarly these high levels of electrical performance can usually only be achieved by the useof polymers and insulation systems that may not have the same reaction to fire characteristicsas the more traditional materials used in other marine cables. In recognition of this,carefulconsideration should be given to the method of installation to select that most appropriate tothe particular application(see also Clause 8).
5 Constructional considerations5.1Selection of conductor
only circular copper conductors，either plain or metal coated， or copper covered steel arerecommended for use in a marine environment.Stranded conductors are recommended forgeneral use. Where the applicable product standard specifies solid conductors，considerationshould be given to the possible effects of vibration (due to the movement of the ship orinstallation) or movement (due to motion of the ship or installation).
The properties of copper conductors should be in accordance with IEC 60228.Joints in solidconductors or complete stranded conductors are not permitted，however joints in individualstrands are allowed.
NOTE When cables are subject to continuous flexing the advice of the manufacture should be sought.5.2Selection of insulation
The range of materials for use as conductor insulation should, where possible，be selectedfrom those listed in the IEC 60092-351 or as given in lEC 60096-O-1 and lEC 61156-5-1.Forcables operating at the higher frequencies the insulation may be solid, cellular or a foam skincomposite.The rated operating temperature of the insulating material should be at least 10 °chigher than the maximum ambient temperature likely to exist, or to be produced, in the spacewhere the cable is installed.
The insulation should be continuous having a thickness as uniform as possible.The insulationshould be applied to fit closely to the conductor.
NOTEThe user should carefully select the insulation material regarding its electrical characteristics and intendeduse in the marine environment.
5.3Cable elements
The cores within each pair,triple,or quad should be clearly identified by colour or number asgiven in the applicable cable standard.The identification used should be durable and legible.
The choice of the maximum average length of lay in the finished cable should be selected withrespect to the specified crosstalk requirements， handling performance and the pair or quadintegrity.
5.4Selection of screen, core screen or shieldlf a screen is required, it may consist of the following:
a) a metallic laminated tape bonded to polyester and a drain wire in direct contact with
the metallic side of the tape,
b) plain or metal coated copper braid,
c) a metallic laminated tape bonded to polyester and a drain wire in direct contact with
the metallic side of the tape with a plain or metal coated copper braid.