Case CX490D - Page 141

3-CONTROLSANDINSTRUMENTS
SCRsystemprotection
Themachinecontrolsystemdetectsandwarnsaboutimproperorevendangerousfunctioningconditionsofthe
SCRsystem:
1.ThelevelofDEF/AdBlue®inthetanklowersuntilthetankiscompletelyempty.
2.ThequalityofDEF/AdBlue®inthetankdoesnotconformtotherequiredspecication,orauiddifferentthan
DEF/AdBlue®islledintotheDEF/AdBlue®tank.
3.OneormorecomponentsoftheSCRsystemhaveafailure.
TheseconditionsshallbepromptlyaddressedinordernottoseverelydamagetheSCRsystem.Therefore,asone
oftheseconditionscomesup,themachinecontrolsystemdisplaysaspecicwarningsequenceinordertoinduce
theoperatortotakeproperactions.
Theinducementsequencehasfoursteps:
A.TheSCRsystemisfunctioninginpropercondition.
B.TheSCRsystemisgettingtoanimproperordangerousfunctioningcondition,andawarningtotheoperatoris
thusgiven.
C.TheSCRsystemisatriskofdamages,andanearlyinducementisthusgiventotheoperatorforstoppingoperation
assoonaspossible,andtakingproperactions.
D.TheSCRsystemisatriskofseriousdamages,andanalinducementisthusgiventotheoperatorforstopping
operationimmediately,andtakingdenitiveactions.
FromthestepBtothestepD,themachinefunctionalitiesarefurtherlimited:
B.Theengineisatratedoutput.
C.Theengineislimitedto70%oftheratedoutput.Aderateiconisdisplayed.
Theengineisderated.
D.Theengineislimitedto60%oftheratedoutput,andtheenginespeedislimitedtolowidle.Anopowerwarning
isdisplayed
Theenginehasnopower.
InthestepDoftheinducementsequence,themachinehasaminimaloperatingcapacity.Thisminimaloperating
capacityisintendedtoreachasafecondition:asasafeconditionisreached,stoptheengine,andmakesuretotake
theappropriateactionrequiredbytheinducementsequence,asforexamplerellingDEF/AdBlue®orrepairingthe
SCRsystem.
NOTICE:TherecommendedpracticeistostopoperationandtakeproperactionsatthestepBoftheinducement
sequence,inordertoavoidseveredamagestotheSCRsystemandtotheothermainsystemsofthemachine.
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