Contact check criteria can be used where the fault current through the breaker is small.Breaker failure protection, 3-phase activation and output (CCRBRF) current criteriacan be fulfilled by one or two phase currents the residual current, or one phase currentplus residual current. When those currents exceed the user defined settings, thefunction is triggered. These conditions increase the security of the back-up tripcommand.CCRBRF function can be programmed to give a three-phase re-trip of the own breakerto avoid inadvertent tripping of surrounding breakers.8.6.3 Function blockCCRBRFI3P*BLOCKSTARTCBCLDL1CBCLDL2CBCLDL3TRBUTRRETIEC09000272_1_en.vsdIEC09000272 V1 ENFigure 78: CCRBRF function block8.6.4 SignalsTable 97:CCRBRF Input signalsName Type Default DescriptionI3P GROUPSIGNAL- Three phase group signal for current inputsBLOCK BOOLEAN 0 Block of functionSTART BOOLEAN 0 Three phase start of breaker failure protectionfunctionCBCLDL1 BOOLEAN 1 Circuit breaker closed in phase L1CBCLDL2 BOOLEAN 1 Circuit breaker closed in phase L2CBCLDL3 BOOLEAN 1 Circuit breaker closed in phase L3Table 98:CCRBRF Output signalsName Type DescriptionTRBU BOOLEAN Back-up trip by breaker failure protection functionTRRET BOOLEAN Retrip by breaker failure protection functionSection 8 1MRK 504 135-UEN ACurrent protection180Technical manual
