RjxMho, zone3Mho, zone2Mho, zone1IEC09000172_1_en.vsdIEC09000172 V1 ENFigure 67: Mho, offset mho characteristicZone 3 can be equipped with a load encroachment function which cuts off a section of thecharacteristic when enabled. The function is activated by setting the parameterLoadEnchModZ3 to Enable. Enabling of the load encroachment function increases thepossibility to detect high resistive faults without interfering with the load impedance. Thealgorithm for the load encroachment is located in the Load encroachment (LEPDIS)function, where the relevant settings can be found. Information about load encroachmentfrom LEPDIS function to zone measurement is sent via the input signal LDCND in binaryformat.7.2.6.3 Basic operation characteristicsEach impedance zone can be enabled and disabled by setting OpModeZx (where x is 1-3depending on selected zone).The zone reach for phase-to-phase fault is set individually in polar coordinates. Theimpedance is set by the parameter ZxFwd and ZxRev and the corresponding angles by theparameter ImpedanceAng. The setting ImpedanceAng is common for all three zones.1MRK 502 048-UUS A Section 7Impedance protection163Technical manual
