Simrad SU90 - Cable Trays; Radio Frequency Interference

SimradSU90
Cabletrays
Allpermanentlyinstalledcablesassociatedwiththesystemmustbesupportedand
protectedalongtheirentirelengthsusingconduitsand/orcabletrays.Theonlyexception
tothisruleisoverthenalshortdistance(maximum.0,5meters)asthecablesruninto
thecabinets/unitstowhichtheyareconnected.Theseshortserviceloopsaretoallowthe
cabinetstomoveontheirshockmounts,andtoallowmaintenanceandrepair.
•Whereverpossible,cabletraysmustbestraight,accessibleandplacedsoastoavoid
possiblecontaminationbycondensationanddrippingliquids(oil,etc.).Theymustbe
installedawayfromsourcesofheat,andmustbeprotectedagainstphysicaldamage.
Suitableshieldsmustbeprovidedwherecablesareinstalledinthevicinityofheat
sources.
•Unlessitisabsolutelyunavoidable,cablesshouldnotbeinstalledacrossthevessel's
expansionjoints.Ifthesituationisunavoidable,aloopofcablehavingalength
proportionaltothepossibleexpansionofthejointmustbeprovided.Theminimum
internalradiusoftheloopmustbeatleasttwelvetimestheexternaldiameterof
thecable.
•Whereaservicerequiresduplicatesupplylines,thecablesmustfollowseparatepaths
throughthevesselwheneverpossible.
•Signalcablesmustnotbeinstalledinthesamecabletrayorconduitashigh-power
cables.
•Cablescontaininginsulationmaterialswithdifferentmaximum-ratedconductor
temperaturesshouldnotbebunchedtogether(thatis,inacommonclip,gland,
conduitorduct).Whenthisisimpractical,thecablesmustbecarefullyarranged
suchthatthemaximumtemperatureexpectedinanycableinthegroupiswithinthe
specicationsofthelowest-ratedcable.
•Cableswithprotectivecoveringswhichmaydamageothercablesshouldnotbe
groupedwithothercables.
•Cableshavingacoppersheathorbraidingmustbeinstalledinsuchawaythat
galvaniccorrosionbycontactwithothermetalsisprevented.
•Toallowforfutureexpansionofthesystem,allcablesshouldbeallocatedspare
conductorpairs.Also,spacewithinthevesselshouldbesetasidefortheinstallation
ofextracables.
RadioFrequencyinterference
Allcablesthataretobepermanentlyinstalledwithin9m(30ft)ofanysourceofRadio
Frequency(RF)interferencesuchasatransmitteraerialsystemorradiotransmitters,
must,unlessshieldedbyametaldeckorbulkhead,beadequatelyscreenedbysheathing,
braidingorothersuitablematerial.Insuchasituationexiblecablesshouldbescreened
whereverpossible.
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