8.7.8 Technical dataTable 199:TRPTTR technical dataFunction Range or value AccuracyBase current 1 and 2 (30–250)% ofIBase ±1.0% of IrOperate time:2 22 2prefI It ln I It æ ö-ç ÷= × ç ÷-è øEQUATION1356 V2 EN (Equation 77)I = actual measured currentIp = load current before overloadoccursIref = reference load currentIp = load current before overloadoccursTime constant τ = (0.10–500.00)minutes±5.0% or ±200 ms whicheveris greaterAlarm level 1 and 2 (50–99)% of heat content operatevalue±2.0% of heat content tripOperate current (50–250)% ofIBase ±1.0% of IrReset level temperature (10–95)% of heat content trip ±2.0% of heat content trip8.8 Breaker failure protection 3-phase activation andoutput CCRBRF8.8.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberBreaker failure protection, 3-phaseactivation and outputCCRBRF3I>BFSYMBOL-U V1 EN50BF8.8.2 FunctionalityBreaker failure protection (CCRBRF) ensures a fast backup tripping of surroundingbreakers in case the own breaker fails to open. CCRBRF can be current-based,contact-based or an adaptive combination of these two conditions.Current check with extremely short reset time is used as check criterion to achievehigh security against inadvertent operation.Contact check criteria can be used where the fault current through the breaker is small.1MRK502052-UEN B Section 8Current protection407Technical manual
