Simrad ST90 - Radio Frequency Interference; Physical Protection of Cables

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442703/B
conduitorduct).Whenthisisimpractical,thecablesmustbecarefullyarranged
suchthatthemaximumtemperatureexpectedinanycableinthegroupiswithinthe
specicationsofthelowest-ratedcable.
6Cableswithprotectivecoveringswhichmaydamageothercablesshouldnotbe
groupedwithothercables.
7Cableshavingacoppersheathorbraidingmustbeinstalledinsuchawaythat
galvaniccorrosionbycontactwithothermetalsisprevented.
8Toallowforfutureexpansionofthesystem,allcablesshouldbeallocatedspare
conductorpairs.Also,spacewithinthevesselshouldbesetasidefortheinstallation
ofextracables.
Radiofrequencyinterference
Allcablesthataretobepermanentlyinstalledwithin9m(30ft)ofanysourceofRadio
Frequency(RF)interferencesuchasatransmitteraerialsystemorradiotransmitters,
must,unlessshieldedbyametaldeckorbulkhead,beadequatelyscreened
Suitablescreeningcanbeestablishedusingsheathing,braidingorothersuitablematerial.
Insuchasituationexiblecablesshouldbescreenedwhereverpossible.
Itisimportantthatcables,otherthanthosesupplyingservicestotheequipmentinstalled
inaradioroom,arenotinstalledthrougharadioroom,highpowerswitchgearorother
potentialsourcesofinterference.Cableswhichmustpassthrougharadioroommustbe
screenedbyacontinuousmetalconduitwhichmustbebondedtothescreeningofthe
radioroomatitspointsofentryandexit.
Physicalprotectionofcables
Cablesexposedtotheriskofphysicaldamagemustbeenclosedinasteelconduitor
protectedbyametalcasingunlessthecable'scovering(forexamplearmourorsheath)is
sufcienttoprotectitfromthedamagerisk.
Cablesexposedtoanexceptionalriskofmechanicaldamage(forexampleinholds,
storage-spacesandcargo-spaces)mustbeprotectedbyasuitablecasingorconduit,
evenwhenarmoured,ifthecablecoveringdoesnotguaranteesufcientprotection
forthecables.
Metallicmaterialsusedforthephysicalprotectionofcablesmustbesuitablyprotected
againstcorrosion.
SimradST90InstallationManual