Sabre 30 - 23:00 UNDERWATER CORROSION

3/21/2017 Sabre30OwnersManual
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NOTE:Anydamagedorfrayedwiremustberepairedorreplaced.
Wiringat12voltDCswitchpanelatthecompanionway.
Terminalstripinstarboardelectricalaccesspanel.
Allgroundwiresinstarboardelectricalaccesspanel.
Wiringatenginegauges.
Enginewiringconnections.
Batterycableconnectionsatbatteriesandmaindisconnectswitch.
Wiringatengineignitionpanelinthecockpit.
Mastwiringplug(s)atmaststepandbaseofmast.Bothplugsshouldbe
disassembledandcleaned.Saltdepositswhichcancauseshortingareverycommoninthis
area.
Wiringforalloptionalequipment,suchasVHFradios,stereos,bilgepumps,etc.
23:00UNDERWATERCORROSION(Cont'd)
NOTE:Optionalequipmentthatwasnotfactoryinstalledmustbewiredwithproper
switches,overcurrentprotectionandgrounding.Allswitchesmust
beinstalledonthe
positive(+)sideofthecircuitwithgroundingbeingaccomplishedthroughthe12voltDC
systemtothebatteries.
Unusualcorrosionordepositsfoundatawireconnectionorpieceofequipmentmustbe
thoroughlycleanedandtheequipmentcheckedforproperoperationandpossibleelectrical
leaks.
Equipmentshowingsignsofmalfunctioningorintermittentoperationmustalsobechecked.
Thiswouldincludesomethingasseeminglyminorasananchorlightflickeringonandoff
atthetopofthemast,indicatingalooseconnectionorshortcircuit.
23:03BONDINGANDLIGHTENINGGROUNDSYSTEM
:Checktheentirebondingandlightening
groundsystemstoassurethattheyareintactandfunctioningproperly.Thepurposeof
thebondingsystemsistoprotecttheunderwaterhardwarefromcorrosionbyprovidinga
lowresistancepathtogroundforanystrayelectricalcurrentswhichmaydeveloponthe
boat.Allunderwaterhardwareistiedtogetherwithawiringsystemwhichterminatesat
oneortwocommongroundterminalsonakeelboltinthebilge.Theintegrityand
operationofthebondingsystemcanbecheckedbyusinganohmmetertoassurethateach
underwaterfittingisbondedtothekeel.Theohmmetermustregister"0"resistancefor
eachfitting.The"LighteningProtectionandBondingSystem"diagramwillhelpin
locatingallfittingsandhardwareconnectedtothebondingsystem.Iflittleorno
contactisfoundbetweenafittingandthekeel,connectionsateachendofthewiremust
becheckedandthewirereplacedifnecessary.Particularattentionshouldbepaidtothe
enginetokeelbondingconductor.Ourexperienceindicatesthatapoorgroundconnection
herecanoftenallowastraycurrenttoleavetheboatbywayofthepropellershaft.
PROPELLERANDSHAFTCORROSION
:Propellerandshaftcorrosionareoneofthemostcommon
resultsofofastraycurrentsituation.Sincethepropellerandshaftaresuchlarge
piecesofhardware,withexcellentelectricalconductivity,theyprovideanidealpathfor
astraycurrenttoleavetheboat.
Inmostcases,thepropellerandshaftareadequatelybondedtothekeelbywayoftheir
connectiontotheengine.However,iftheenginetokeelgroundisnotintact,orifa
goodgroundisnotachievedthroughtheshaftcouplingconnectiontotheengine,corrosion
canoccur.
Evenwithallpossiblesourcesofstraycurrentbeingminimized,ifmaybenecessaryto
installaseparategroundfromthepropellershafttothekeel.Thisisaccomplishedby
installationofa"shaftgroundingbrush"ontheshaftbetweenthestuffingboxandthe