General settings................................................................... 169Percentage restrained differential operation........................ 170Negative sequence internal/external fault discriminatorfeature.................................................................................. 172Open CT detection............................................................... 173Other additional options....................................................... 174Low impedance restricted earth fault protection REFPDIF ........... 175Identification.............................................................................. 175Application................................................................................. 175Transformer winding, solidly earthed................................... 176Transformer winding, earthed through zig-zag earthingtransformer........................................................................... 177Autotransformer winding, solidly earthed............................. 178Reactor winding, solidly earthed.......................................... 178Multi-breaker applications.................................................... 179CT earthing direction............................................................ 180Setting guidelines...................................................................... 180Setting and configuration......................................................180Settings................................................................................ 181Section 8 Impedance protection...................................................183Full-scheme distance measuring, Mho characteristic ZMHPDIS .. 183Identification.............................................................................. 183Application................................................................................. 183Generator underimpedance protection application.............. 183Setting guidelines...................................................................... 183Configuration........................................................................ 183Settings................................................................................ 184High speed distance protection ZMFPDIS..................................... 187Identification.............................................................................. 187Application................................................................................. 188System earthing................................................................... 188Fault infeed from remote end............................................... 191Load encroachment..............................................................192Short line application............................................................ 193Long transmission line application....................................... 194Parallel line application with mutual coupling....................... 194Tapped line application........................................................ 200Setting guidelines...................................................................... 203General.................................................................................203Setting of zone 1.................................................................. 203Setting of overreaching zone................................................203Setting of reverse zone........................................................ 204Setting of zones for parallel line application......................... 205Table of contents4 Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062Application manual
