Function Range or value AccuracyPhase current pickup forblocking of contactfunction(5-200)% oflBase ± 1.0% of In at I £ In± 1.0% of I at I > InReset ratio > 95% -Timers (0.000-60.000) s ± 0.5% ±10 msOperate time for currentdetection35 ms typically -Reset time for currentdetection10 ms maximum -8.6 Pole discrepancy protection CCRPLD (52PD)8.6.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberPole discrepancy protection CCRPLDPDSYMBOL-S V1 EN52PD8.6.2 FunctionalityCircuit breakers and disconnectors can end up with their 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 affected breaker is tripped to correct such a situation. If the situationwarrants the surrounding breakers should be tripped to clear the unsymmetrical loadsituation.The pole discrepancy function operates based on information from the circuit breakerlogic with additional criteria from unsymmetrical phase currents when required.1MRK 502 043-UUS B Section 8Current protection219Technical Manual
