6.9.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberPole discordance protection CCRPLDPDSYMBOL-S V1 EN52PD6.9.2 FunctionalityCircuit breakers and disconnectors can end up with the phases in different positions(close-open), due to electrical or mechanical failures. An open phase can causenegative and zero sequence currents which cause thermal stress on rotating machinesand can cause unwanted operation of zero sequence or negative sequence currentfunctions.Normally the own breaker is tripped to correct such a situation. If the situation persiststhe surrounding breakers should be tripped to clear the unsymmetrical load situation.The pole discordance function operates based on information from the circuit breakerlogic with additional criteria from phase selective current unsymmetry.6.9.3 Function blockCCRPLDI3P*BLOCKCLOSECMDOPENCMDEXTPDINDTRIPSTARTIEC08000041 V1 ENFigure 59: CCRPLD function block6.9.4 SignalsTable 79:CCRPLD Input signalsName Type Default DescriptionI3P GROUPSIGNAL- Three phase group signal for current inputsBLOCK BOOLEAN 0 Block of functionCLOSECMD BOOLEAN 0 Close order to CBOPENCMD BOOLEAN 0 Open order to CBEXTPDIND BOOLEAN 0 Pole discordance signal from CB logic1MRK 511 287-UEN A Section 6Current protection137Technical manual
