1. Set DirModeZ4 to Reverse.2. Set MhoCharZ4 to Directional, if CharPGZ4 or CharPPZ4 is set to Mho.3. Set Z1 to 4.2 ΩZ1 = 0.85 · ZLine, posseq = 0.85 · 0.28 · 17.5 = 4.2 Ω4. Set RFPP4 to 4 Ω, if CharPPZ4 is set to Quadrilateral.Setting RFPP4 ≈ Z4 is proposed5. Set RFPG4 to 8 Ω, if CharPGZ4 is set to Quadrilateral.RFPE4 ≈ 2 · Z4 setting is proposed (should never be larger than 4.5 · X4 where X4is the reactive part of Z4)6. Set OpModetPGZ4 to Enabled.Zone 4 phase to earth loop gives trip.7. Set OpModetPPZ4 to Enabled.Zone 4 phase to phase loop gives trip.8. Set time delays to trip8.1. Set tPPZ4 to 0.400 sZone 4 phase to phase loop gives trip after a short delay.8.2. Set tPGZ4 to 0.400 sZone 4 phase to ground loop gives trip after a short delay.The time delay for zone 4 need margin to assure selectivity to zone 1 of lines out fromsubstation A. A delay time difference of 0.4 s between the zones is sufficient.3.1.4 Calculating settings for phase selection with load encroachmentFDPSPDIS (21)Correct phase selection for faults within zone 1 and 2 is required.1. Set GlobalBaseSel to 12. Set the minimum apparent resistance during non-faulted conditions:2.1. Set RLdFwd to 70 Ω2.2. Set RldRev to 70 ΩThe minimum apparent resistance during non-faulted conditions is calculated as:( )22min,max0.9 138, Re 0.8 85.7180extVRLdFwd Rld v P×£ × = = WGUID-0428FFD5-8487-414F-9974-E21565F520DA-ANSI V1 EN (Equation 17)3. Set LdAngle to 30ºIt is normally considered that the apparent impedance during non-faulted conditionhas a phase angle in the range ± 30º.4. Set the zero and positive sequence reactance reach4.1. Set X1 to 50 Ω1MRK 506 334-UUS A Section 3REL650 setting examples55Application manual
