Eaton Cutler-Hammer Digitrip RMS 910 Instructions Manual

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

11.29-889APage13AuxiliaryPower Module1.2.2.1ROMError...SeeI.L.Ifthemessage,“ROM Error. . .SeeI.L.”,scrollsacrossthedisplaywindow,itmeans thatanon-fatal errorhasbeendetectedsomewhereinthe TripUnit'snon-volatilememory.TheTripUnitwill still functiontoprotectthe cir-cuit,but the calibrationmay be degradedbyafewper-cent.The scrollingmessage willnot remain inthewindowconstantlybutis repeated periodicallytoremind youtoreplace theTripUnit.1.3 Frame Rating, SensorRating(where applicable)and Rating PlugsThe Frame Rating of acircuit breaker isthe maximumRMScurrentit cancarry continuously. The maximumShort-Circuit Current Ratingsofthe circuitbreaker areusually relatedtotheFrame Ratingaswell.Itis oftentimesdesirabletobeabletochoosea currentvalue(ln),lessthan thefullframerating,tobe the basisfor the circuit breaker’s protectionfunctions,withoutaffecting its short-circuit current capability.For the DigitripRMS910Trip Unit the maximum continuouscurrent(ln)issetbythe Rating Plug(and/or Current Sensors,whereapplicable)-see Section6forspecific instructionsfor your circuit breakertype.The(Current)SensorRating(whereapplicable)is themaximum RMS current the circuit breakercancarrywiththe specifiedcurrentsensors installed. The SensorRat-ing can be thesame or less than the Frame Rating,butnot greater.The Rating Plug(see Fig.4) fits into a special cavitytocomplete the Trip Unit (see Fig. 1).Fig.7CAUTIONBEFORE YOU FITTHERATINGPLUGINTO THETRIPUNIT,BESURE TO CHECKTHATTHEBREAKERTYPE ANDFRAMERATING(ORSENSOR RATINGIFAPPLICABLE), MATCHTHOSEPRINTED ONTHERATING PLUG COVER.INSTALLINGARATINGPLUGTHATDOESNOT MATCH THEBREAKERTYPEANDFRAMERATING(OR SENSORRATING,IFAPPLICA-BLE), CAN PRODUCE SERIOUS MISCOORDINATIONAND/ORFAILURE OF THE PROTECTION SYSTEM.After installing the RatingPlug,press andreleasethe‘TRIPRESET"push-buttonto turnoffanyilluminatedLEDs.Thepurposeoftherating plugisto setthevalueofln,thebasis fortheTripUnit protectionfunctioncurrentsettings.(See Section 3 fordetails.)Each circuitbreakerframeratingrepresents themaximumcurrentit cancarrycontinuously. However forproper coordinationofover-current protection,itis often desirable tochoosedif-ferentlevelsoflnfor different circuit breakersofthe sameframerating.An assortmentof ratingplugswithdifferentlnvalues is available foreachbreaker framerating(Seecircuitbreakerinstruction leaflet supplements listed inSection 6)togive the user flexibility to change the valueoflnwithouthaving to changetheprimary current sen-sors onthe breaker. By changing the ratingplug, the usercaneasily change the rangeofcurrent protection settingswithout having toremove the circuit breaker from itsenclosure.For example,ifone expects acircuitto carry600Aini-tially, but then increase to 1400Ain the future,one couldinitially install 1600Acables anda1600Abreaker framewith the Trip Unit rating plug whoseln=800A. Then lateron when the additional load is ready to come on line, therating plug could be exchanged for one withln= 1600A ,F;T*NEffective May 1997