Simrad ST90 - Basic Cable Requirements; Cable Trays

442703/B
233
Basiccablerequirements
Itisveryimportantthatallsystemscablesareinstalledcorrectly.Allcablesmustbe
properlysupportedandprotected,andallrelevantprecautionsmustbemadetoprevent
unwantednoise.
Topics
Cabletrays,page233
Radiofrequencyinterference,page234
Physicalprotectionofcables,page234
Groundingofsystemcables,page235
Cableconnectionsandterminations,page235
Cableidentication,page235
Cableglandsandterminationprocedures,page236
Cabletrays
Allpermanentlyinstalledcablesassociatedwiththesystemmustbesupportedand
protectedalongtheirentirelengthsusingconduitsand/orcabletrays.
Theonlyexceptiontothisruleisoverthenalshortdistance(maximum.0.5meters)as
thecablesrunintothecabinets/unitstowhichtheyareconnected.Theseshortservice
loopsaretoallowthecabinetstomoveontheirshockmounts,andtoallowmaintenance
andrepair.
1Whereverpossible,cabletraysmustbestraight,accessibleandplacedsoasto
avoidpossiblecontaminationbycondensationanddrippingliquids(oil,etc.).
Theymustbeinstalledawayfromsourcesofheat,andmustbeprotectedagainst
physicaldamage.Suitableshieldsmustbeprovidedwherecablesareinstalled
inthevicinityofheatsources.
2Unlessitisabsolutelyunavoidable,cablesshouldnotbeinstalledacrossthevessel's
expansionjoints.Ifthesituationisunavoidable,aloopofcablehavingalength
proportionaltothepossibleexpansionofthejointmustbeprovided.Theminimum
internalradiusoftheloopmustbeatleasttwelvetimestheexternaldiameterof
thecable.
3Whereaservicerequiresduplicatesupplylines,thecablesmustfollowseparate
pathsthroughthevesselwheneverpossible.
4Signalcablesmustnotbeinstalledinthesamecabletrayorconduitashigh-power
cables.
5Cablescontaininginsulationmaterialswithdifferentmaximum-ratedconductor
temperaturesshouldnotbebunchedtogether(thatis,inacommonclip,gland,
Cablelayoutandinterconnections