Eaton Cutler-Hammer Digitrip RMS 910 Instructions Manual

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

I.L.29-889APage32APPENDIXB Interpreting DisplayCodesAfterCircuitBreakerTripsGiven a1600Aframecircuitbreaker with anln=1000Arating pluginstalled.NOTICEFOLLOWINGLD7TRIPOPERATIONS,ITISESSEN-TIAL THATANYCAUSEOFOVERLOADTRIP BECORRECTEDPRIOR TORECLOSINGTHECIRCUITBREAKER.SHOULDIT NOTBECORRECTEDANDTHECIRCUITBREAKER BE RE-CLOSEDTOOQUICKLY,THENBECAUSE OFTHE INHERENTLONGTIMEMEMORYFUNCTION (SEENOTEINSECTION3.3),THELONGDELAYTRIPELEMENTWILL OPER-ATE FASTERTHANTHE RELATEDTIME-CURRENTCURVE INDICATES.THE AMOUNT OFTIMEREQUIREDTO CLEAR THELTMMEMORY CIRCUITISAFUNCTIONOFTHELONGDELAYTIMESETTING(SEEFIG.3.3).THELONGERTHE DELAYSETTING,THELONGER THETIMEREQUIREDTO RESETTHE MEMORY.TOTALMEMORYCLEARING TIME COULD BEUPTOTWELVE(12)MINUTES.THELTMCAN BERESETQUICKLYASDESCRIBED INSECTION4.4(3).TheLTM memory function,simulatestheconventionalthermaltype(bi-metal)circuit breakerTripUnit,andservesausefulfunction by allowing theload conductorsto cool downafter anoverloadcondition.After correctingthe causeoftheoverloadtrip(LDT),allow fortheLTMmemorycircuitto resetandreclosethe circuit breakerto restorepowertotheloadcircuit.Note:As thecurrent approached the overload condi-tion,priortotheoverloadtripoperation, the follow-ing Trip Unitindicationswould havebeen visible.CASE1-OverloadTripOperation andHighLoadConditionLongDelay Current (Pick-up)Setting=1.0,/r=1000AAssume aprolonged1500Aoverloadconditionwhichresultsinanautomaticbreakertrip operation.Thefollow-ingwill occur:•The Long DelayTripLEDwillturn“On”(seeFig.1).• The coded message“LDT”will appearintheDisplayWindow(seeFig.1).•TheLongDelayRelay inthe Power/RelayModule(see Figs.2 and5)willoperatetoclosetheremoteLongDelayTripAlarmContact.Operator Actions:Observe the modeoftripLEDand codedmessageinthe Display Window.Press and release“STEP”push-button(see Fig.1).This will clearthecoded causeoftripmessage intheDisplay Window.Viewvaluesofphasecurrentsin DisplayWindow(see Fig.1)e.g., 1.50 kA.Note:The phase currentshown willbe thatidentifiedbythe“green”LED (see Fig.1) thatisturned“On”,assume“lA”.(It may notbe the faulted phase.)Press and releasethe“STEP” push-buttontoviewcurrentvalues similarto“lA”,“lB”,“lc”,and “lD”Eachvalue of phasecurrentkA appearing in theDisplay Window, is the valueatthe timeofthetripoperation.RECORD allValuesofinterest;notewhich“RED”LEDs are lightedBEFORE resetting the Trip Unit.Reset theTrip Unitbypressing and releasing the‘Trip Reset” push-button(lower right cornerofTripUnit,see Fig. 1).All coded messages and/orcur-rentvalues in thedisplay window and the cause oftrip LED willturn“Off”, and the Remote Alarm con-tacts in the Power / Relay Module will be reset(open).1.2.7.3.4.•The“HILD”message would begin to flash in the win-dowwhen the overload conditionhadexceeded 0.85x/rfor40secondsor longer.Toclear the“HILD”mes-sageand to view thepresentmagnitudesofthe cur-rents,press and release the(Black)“STEP”pushbutton onthe display panel.Rememberto push the“STEP1button several timestobesureyou see valuesofcurrents in all phases,and ground/neutral as appli-cable.5.6.• The“High-Load” Relay in the Power / Relay Module(see Figs. 2, 5 and Section 1.4) would have beenpicked up (aftera 40-second delay), to close theremote High Load Alarm Contact. Press and releasethe‘TRIP RESET” push button toreset the High LoadF:T*N Effective May 1997