Restrained and unrestrained limits of the differentialprotection................................................................................94Fundamental frequency negative sequence differentialcurrents.................................................................................. 96Internal/external fault discriminator........................................ 98Unrestrained, and sensitive negative sequence protections 101Instantaneous differential currents....................................... 103Harmonic and waveform block criteria................................. 103Switch onto fault feature.......................................................104Logic diagram.......................................................................105Technical data........................................................................... 110Restricted earth-fault protection, low impedance REFPDIF .......... 110Identification.............................................................................. 110Functionality.............................................................................. 111Function block........................................................................... 111Signals.......................................................................................111Settings......................................................................................112Monitored data...........................................................................112Operation principle.................................................................... 113Fundamental principles of the restricted earth-faultprotection..............................................................................113Operate and restrain characteristic...................................... 115Calculation of differential current and bias current............... 116Detection of external earth faults..........................................117Algorithm of the restricted earth-fault protection.................. 118Technical data........................................................................... 1191Ph High impedance differential protection HZPDIF .....................119Identification.............................................................................. 119Introduction................................................................................120Function block........................................................................... 120Signals.......................................................................................120Settings......................................................................................121Monitored data...........................................................................121Operation principle.................................................................... 121Logic diagram.......................................................................121Technical data........................................................................... 122Section 7 Impedance protection...................................................123Power swing detection ZMRPSB ...................................................123Identification.............................................................................. 123Functionality.............................................................................. 123Function block........................................................................... 123Signals.......................................................................................124Settings......................................................................................124Table of contents3Technical manual
