Simrad ST90 - Page 231

442703/B
229
ThegatevalveismanufacturedbyLKValves.Formoredetailedinformationabout
thegatevalveandtheGateValveControlUnit,refertothetechnicaldocumentation
providedbythemanufacturer.
Howitworks
Whenthegatevalveisopen,thelimitswitch"NC"ontheisalsoopen.Oncethegate
valveleavesthe"openposition"(startstoclose)the"NC"limitswitchisalsoclosed.
ThismakesoptocouplerU7closetoo,sending"Inhibit"totheCPUontheHoistControl
circuitboard.Thetransducercanthennotbelowered.
U2is"closed"whenthetransducerisfullyretracted.Thegroundlevelfrompin19in
theGateValveControlUnitisthenpassedtopin3,andtherelaybetweenpins2and3
(intheGateValveControlUnit)isthenactivated.Pin6is+24VDC.Whenactivated,
thisrelayallowsthegatevalvetoclose.U2is"open"whenthetransducerisnotfully
retractedup,thisisanywherebetweenfullyloweredand"almostup".Therelaybetween
pins2and3intheGateV alveControlUnitisthendeactivated.Thispreventsthegate
valvefromclosing.
IfyouloosepowerintheMotorControlUnitwhilethetransducerislowered,U2willbe
kept"open"duetothelackofpower.Thiswillcausetherelaybetweenpins2and3in
theGateV alveControlUnittodeactivate.Thispreventsthegatevalvefromclosing.
Minimumcablerequirements
•Conductors:4x0.75mm
2
•Screen:Overallbraided
•Voltage:60V
•Maximumouterdiameter:Denedbythecablegland
Relatedtopics
Cabledrawingsandspecications,page206
Cablelayoutandinterconnections