DB300

11.INTRODUCTIONTheDB-300isintendedastheswitchingelementinadynamicbrakingsystem.TheDB-300canswitchupto300Aat730Vdcintoaresistiveload.ThepurposeofthedynamicbrakingsystemistoprovidetheMicrodrive,MicrofloorMicrovectorwiththeabilitytocopewithregenerationofthemotorsuchasmaybeexperiencedduringthebrakingofahighinertialoadorwhenloweringacranehoist.Upto220kWofregeneratedenergymaybeswitchedbyeachDB-300.Theeffectofthisactionisthatthemechanicalenergyintheloadisconvertedtoheatintheloadbankandthemotorisrapidlydecelerated.TheDB-300isaswitchingmodule,controlledbytheMicrodrive.UptofourDB-300s,eachwithaseparateresistiveloadbank,maybeconnectedtotheMicrodrive.Theloadbankwillneedtobedesignedtosuittheindividualapplication.22.SPECIFICATIONSDCSwitchingElement:DCOperatingVoltage730VMaximumCurrent300A(R=2.4Ω)MaximumContinuousCurrent140A(R=5.2Ω)ProtectionOverTemperature,ExternalThermostatInput.MaximumAmbientTemp40°CForcurrentsgreaterthan140A,refertothederatingchartshowninFigure2.1.DB300deratingchart(absolutemaximum)toff[s]ton[s]0.111010010001101001000150A200A250A300AFigure2.1DB-300DeratingChartACFanSupply:SupplyVoltage380-440Vac,-20/+10%,1~,48-62HzSupplyCurrent90mANominal,100mALockedRotor.33.INSTALLATIONANDCOMMISSIONINGDuetothehighswitchingspeedandcurrentsintheDB-300,specialwiringpracticesmustbeobserved.Amulticorecableforthepowerinputandoutputisrecommended.Alternatively,twoseparatecables,securelycabletiedtogetherat200mmintervalswithoutanygapsbetweenthem,maybeused.Thisminimisesthecableinductance.Donotrunpowerandthecontrolwiringtogether.Theresistorbankmustbeofnon-inductiveconstruction.Figure3.1showsdetailsoftheDB-300wiring.BOARDTOCONTROLFORFANFUSED400VSUPPLYTHERMOSTATRESISTORBANK1TORESISTORBANK2EARTHTODCBUSMULTICORECABLEORSINGLECORECABLECABLETIEDTOGETHERBANK1TORESISTORFUSED400VSUPPLYRESISTORBANK2THERMOSTATFORFANEARTHFigure3.1DB-300WiringDiagram43.1MountingtheDB-300ThewiringbetweentheMicrodriveandtheDB-300shouldbekeptasshortaspossible(lessthanthreemetres).ThemaximumcablelengthbetweentheDB-300andtheresistorbankdependsonanumberoffactors.Ingeneral,anylengthunder25meterswillcausenodifficulties.Agreaterlengthisusuallypossible.RefertoAppendixAfordetailsonhowtocalculatethemaximumlength.ThemountingdimensionsareshowninFigure3.2.Ensurethattheairflowfromthefanisnotobstructed.Allowatleast20mmclearanceonallsides.163190.0c/c210260110.0c/c106.0DIA.104811-053RevBDIMENSIONSINMMFigure3.2DB-300DimensionsInstallationandCommissioning53.2WiringtheDB-300totheDCBusWARNING:IsolatetheMicrodriveandallowstoredchargetodissipatebeforeproceeding.ConnecttheDCbusterminalstotheDB-300terminals,labelled+BUS/RBANKand-BUS,usingalowinductancecableofshortestpossiblelength.Becarefultoobservecorrectpolarity.Thecableneednotberatedforcontinuouscurrent.Theratingmaybereducedwhentakingintoaccountthemaximumdutycycleexperienced.3.3EarthingtheDB-300ConnectanearthconductortotheDB-300earthterminal.3.4WiringtheDB-300totheResistorBankConnecttheresistorbanktotheDB-300terminals,labelled+BUS/RBANKandRBANK,usingalowinductancecable.ThelengthisnotallowedtoexceedthatcalculatedaccordingtoAppendixA.Considertheactualdutycyclewhenratingthecable.WhenconnectingmultipleDB-300s,eachDB-300musthaveaseparateresistorbank.3.5WiringtheDB-300FanSupplyConnecttheDB-300fantoasuitablyfused400Vsupply.3.6WiringtheDB-300totheMicrodriveControlBoardUsethesuppliedcontrolcable(3meterslong)tointerconnecttheMicrodriveandtheDB-300.PlugoneendofthecableintotheconnectorlabelledP4ontheMicrodrivecontrolboard.PlugtheotherendintotheconnectorlabelledCONTROLontheDB-300.WhenusingmorethanoneDB-300,connectthesecondDB-300CONTROLinputtothefirstDB-300CASCADEoutput.Runthecontrolcableseparatefromthepowercables(0.3mminimumseparation).3.7WiringtheResistorBankThermostatConnecttheresistorbankthermostattotheDB-300externalmicrotherminput,usingascreenedcable.Connectthescreentoearthinoneplaceonly.Ascrew,intheheatsinkT-slotbelowthethermostatterminals,isprovidedforthispurpose.Thisinputprovidesafirstlevelofprotectiononly.Additionalprotectionisstillrequired(referSection4.1).Linkthethermostatinputstogetheriftheyarenotused.3.8PowerUpBeforeapplyingpower,doublecheckthatallconnectionsarecorrectlymade.Anyincorrectconnectioncanresultinextensivedamage!Onpowerup,theBUSLIVE(red)andPOWER(green)LEDsshouldlightandthefanshouldturnon.TheBRAKEON(red)LEDshouldremainoff.InstallationandCommissioning6InstallationandCommissioning3.9ConfiguringtheMicrodriveorMicrofloDynamicBrakeThermalModelConfigurethecontrolboardfordynamicbrakeoperationbyfollowingthestepsdetailedbelow.WARNING:EnsurethattheMicrodriveissetupasdetailedbelowasincorrectdynamicbrakethermalmodelsettingscouldallowbrakeresistordamage.MakesurethattheMicrodriveissettocommissioningmodewithextendedmenuscreens.GotoScreen98ontheMicrodrivebyholdingdownthe+key.Checkthatthescreenreads“COMMISSION=Y”.IfsecurityaccesshasbeenrestrictedandyoucanonlygotoScreen97,regainsecurityaccessbyreleasingthe+keythenholdingitagainforfiveseconds.Screen98willappearandcanbesetto“COMMISSION=Y”byholdingthemodekeyandatthesametimepressingthe+key.GotoS