8.9.2 FunctionalityAn open phase can cause negative and zero sequence currents which cause thermalstress on rotating machines and can cause unwanted operation of zero sequence ornegative sequence current functions.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 protection function CCPDSC operates based on informationfrom auxiliary contacts of the circuit breaker for the three phases with additionalcriteria from unsymmetrical phase currents when required.8.9.3 Function blockCCPDSCI3P*BLOCKBLKDBYARCLOSECMDOPENCMDEXTPDINDPOLE1OPNPOLE1CLPOLE2OPNPOLE2CLPOLE3OPNPOLE3CLTRIPSTARTIEC13000305-1-en.vsdIEC13000305 V1 ENFigure 189: CCPDSC function block8.9.4 SignalsTable 207:CCPDSC Input signalsName Type Default DescriptionI3P GROUPSIGNAL- Three phase currentsBLOCK BOOLEAN 0 Block of functionBLKDBYAR BOOLEAN 0 Block of function at CB single phase auto re-closingcycleCLOSECMD BOOLEAN 0 Close order to CBOPENCMD BOOLEAN 0 Open order to CBEXTPDIND BOOLEAN 0 Pole discordance signal from CB logicPOLE1OPN BOOLEAN 1 Pole one opened indication from CBPOLE1CL BOOLEAN 0 Pole one closed indication from CBPOLE2OPN BOOLEAN 1 Pole two opened indication from CBPOLE2CL BOOLEAN 0 Pole two closed indication from CBPOLE3OPN BOOLEAN 1 Pole three opened indication from CBPOLE3CL BOOLEAN 0 Pole three closed indication from CBSection 8 1MRK502052-UEN BCurrent protection414Technical manual
