Kongsberg EA440 - Page 30

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Reducingpropellernoise
•Eachtransducermustbeinstalledasfarawayfromthepropellersaspossible.
•Sufcientclearancebetweenthepropellersandthehull,therudderandthekeelmust
beprovided.
•Placethezincalloyanodesinplaceswherethewaterowistheleastdisturbed.
•Ensurethatthepropellersbladesarecorrectlydesignedandwithoutdamages.
•Theuseofabafebetweenthepropellersandthetransducermayreducenoise
appreciably.
•Staticdischargescausedbytherotatingpropellershaftmayberemovedbyproper
groundingorbymountingacoalbrushfromtheshafttovesselground.
Reducingrattlenoise
Ensurethatnopartsnearthetransducerscanrattleasaresultofwateroworvibrations.
Reducinginterference
Interferencefromthetransmissionpulsesfromotherhydroacousticinstrumentson
boardthevesselisdifculttoavoid.Theproblemmaybereducedbychoosingthe
workingfrequenciescarefullyandtosomeextentbyseparatingthedifferenttransducers.
Onvesselswithalargenumberofseparatehydroacousticsystemsinstalledandin
simultaneoususe,aseparatesynchronizingsystem(forexampletheK-Sync)should
beconsidered.
Reducingelectricalnoise
•PlacethetransducercablesinametalconduitfromthetransducertotheWBT.
TerminatetheconduitasclosetothetransducersandWBTaspossible.
•Makesurethatallunitsareproperlygrounded,asthisisimportanttoavoidelectrical
noise.
•Useshieldedcableswithcorrectgrounding.
•SeparateEA440cablesfromothercableswithhighvoltages,largecurrentsor
transients.Placeallhighvoltagepowercablesinmetalconduits.
EA440Installationmanual