Eaton Cutler-Hammer Digitrip RMS 910 Instructions Manual

Also see for Digitrip RMS 910: Instructions Instructional Leaflet Instruction leaflet

I.L.29-889APage15The relaysoperatewhentheTripUnitdetects thefollow-ing conditions:AvailableSettings2,2.5,3,4.5,6,Si,S2idShortDelaySettingU]x/r• Short-CircuitTripAlarm•High LoadAlarm•LongDelayTripAlarm•Groundfault TripAlarm(types LIG,LSG,LSIG)orNeutralOver-CurrentAlarm(typesLI,LSLSI)•In addition,thePower/RelayModulealsocontains theINCOM®COMMUNICATIONSCLOSEcontact,whichoperatesthe circuitbreaker’sclosingrelease,oncommandfromINCOM/IMPACC®. (See Section5.8.)asshownin Fig.2.Eachrelaycontactis ratedfor120V,50/60Hzac,1.0Ampere.The HighLoadAlarm contactoperatesaftertheload currenthasexceeded85%ofthe longdelaycurrentsetting,lrfor40seconds.The40-second delayallowsthesystemto“ridethrough”momentaryhigh load condi-tionsandavoidnuisancealarms.The LongDelay TripAlarm contactoperatesafterthebreakerTRIPSduetoover-load conditions whichexceeded the Long DelayTripsettings.ForType LSG,LIGandLSIGTripUnits,theground FaultTripAlarmcontactoperatesafter the breaker TRIPS duetoconditionswhichexceed the Ground Fault protectionsettings.ForTypeLS,LIandLSI TripUnits,the NeutralCurrent Alarmcontactoperates when the neutralcurrentexceeds the LongDelayCurrent protection setting,lrInMultiplesofLongDelaySetting*X©Ur)SiandS2ValuesareSpecifiedonRatingPlugFig.8.3Short DelayCurrent SettingsThe Short-CircuitTripAlarm contactoperatesafterthebreaker TRIPSduetoanINSTantaneoustrip,Short-DelayTrip, Discriminator trip,a Fixed InstantaneousOverRIDe trip, oraRatingPLUG tripasapplicable.Evenwithoutavailableexternalcontrolpower,oncetheloadcurrentthroughthecircuit breakerexceeds approxi-mately20%(40%ifsingle phase)ofthe frame/currentsensor rating,thegreenLED will flash“On andOff”onceeachsecond,toindicate theTripUnitis energizedandoperatingproperly,andall protection functionsarefunc-tioning. However,thedisplaywindowwill remaindark.Note:If120VACcontrol power islosttothePower/RelayModule,theLOCKOUTaftertripwillresetandthe breaker can beclosedagain. However thecauseof trip bit will remainsetintheDigitrip’snonvolatilememoryanda cause of tripmessage willreappearwhen controlpowerreturns.Acomplete clearingofcause oftrip bistory maybeaccomplishedbydepressingthe reset push-button when theDigitripunitis powered up.(Indicatedby theUnit Statusflashing)1.5Potential Transformer ModuleThe Potential TransformerModule(PTM)(seeFig.6)isalsoseparatefrom the RMS 910TripUnit andisnotrequired for theTripUnittoperformitsprotection func-tions. ThePotentialTransformer Module providesthree-phaseprimary voltage information necessaryforthe Trip Unittocalculatepower and energy values.(SeeFig.2.)The Potential Transformer Module primary terminals aresuitable for all system voltage ratings up through 600V,50/60 Hz,and are connected to the primary phase con-ductors inside the breaker,providing stepped downvolt-age signalstoinput terminalsVA,VB,VcandVNontherearofthe Digitrip 910 Trip Unit housing.Long DelayFimeAvailableSettings2,4,7.10,12,15,20,24Secondsat6 TimesLong Delay Setting(MFig. 8.2Long Delay Time SettingsE:T'NEffective May 1997