Sl.No Measuring Loop Voltage Phasor Current Phasor1 IL1 1 0UL E U- 1IL2 IL2 2 0UL E U- 2IL3 IL3 3 0UL E U- 3ILOperate timeThe operate time delay for zone 2 can be provided using the setting tZ2.Zone 2 is provided load encroachment detection feature based on positive sequencecomponents measurements.. This feature avoids the function from operating due toload encroachment. The load encroachment feature for zone 2 can be set usingLoadEnchModZ2 to On or Off.7.10.7.3 Operation principle of zone 3Zone 3 is used to cover up to the HV side of the transformer, interconnecting busnetwork and outgoing lines. The time to trip should be provided in order to coordinatewith the transmission line protection.The zone 3 will provide protection from phase-to-earth, phase-phase and three-phasefaults on the HV side of the system. The zone 3 functionality is same as zone 2 hencethe explanation of zone 2 applies except the zone 3 has separate reach (Z3Fwd,Z3Rev), operate timer (tZ3) and load encroachment enable (LoadEnchModZ3)settings.7.10.7.4 Load encroachmentThe load encroachment characteristics can be set for zone2 and zone3. Loadencroachment can be enabled for zone 2 by setting LoadEnchModZ2 to On. Similarlythe load encroachment for zone 3 can be enabled by setting LoadEnchModZ3 to On.The load encroachment characteristic is based on positive sequence quantities and canbe set using the settings RLd and ArgLd.RLd is the positive sequence resistive reach value in percentage. ArgLd is angle indegrees from the origin to the resistive axis as shown in Figure 154.Section 7 1MRK502052-UEN BImpedance protection330Technical manual
