Function Range or value AccuracyTimers (0.000-60.000) s ± 0.5% ±10 msOperate time forcurrent detection20 ms typically -Reset time for currentdetection10 ms maximum -8.7 Pole discordance protection CCRPLD8.7.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberPole discordance protection CCRPLDPDSYMBOL-S V1 EN52PD8.7.2 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.8.7.3 Function blockCCRPLDI3P*BLOCKCLOSECMDOPENCMDEXTPDINDTRIPSTARTIEC08000041 V1 ENFigure 83: CCRPLD function block1MRK 504 135-UEN A Section 8Current protection185Technical manual
