IL3=INIL1=INen06000553.vsdIEC06000553 V1 EN-USFigure 244: The currents in the phases at a double earth faultThe function has a block input (BLOCK) to block start from the function ifrequired in certain conditions.8.19.3 Setting guidelines SEMOD167997-4 v5The parameters for the Phase preference logic function PPLPHIZ are set via thelocal HMI or PCM600.Phase preference logic function is an intermediate logic betweenDistance protection zone, quadrilateral characteristic functionZMQPDIS and Phase selection with load encroachment,quadrilateral characteristic function FDPSPDIS. Phase selectionand zones are set according to normal praxis, including earth-faultloops, although earth-fault loops will only be active during a cross-country fault.GlobalBaseSel: Selects the global base value group used by the function to defineIBase, UBase and SBase as applicable.OperMode: The operating mode is selected. Choices includes cyclic or acyclicphase selection in the preferred mode. This setting must be identical for all IEDs inthe same galvanic connected network part.UPN<: The setting of the phase-to- earth voltage level (phase voltage) which isused by the evaluation logic to verify that a fault exists in the phase. Normally in ahigh impedance earthed system, the voltage drop is big and the setting can typicallybe set to 70% of base voltage (UBase)Section 8 1MRK 506 369-UEN BImpedance protection448 Line distance protection REL670 2.2 IECApplication manual
