
vi L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
TABLE OF CONTENTS
5.5.4 87L power system .......................................................................................................... 5-140
5.5.5 Breakers .............................................................................................................................. 5-147
5.5.6 Disconnect switch control .......................................................................................... 5-153
5.5.7 FlexCurves.......................................................................................................................... 5-158
5.5.8 Phasor Measurement Unit.......................................................................................... 5-165
5.6 FlexLogic.............................................................................................................. 5-185
5.6.1 FlexLogic operands........................................................................................................ 5-185
5.6.2 FlexLogic rules.................................................................................................................. 5-197
5.6.3 FlexLogic evaluation...................................................................................................... 5-197
5.6.4 FlexLogic example..........................................................................................................5-198
5.6.5 FlexLogic equation editor............................................................................................ 5-203
5.6.6 FlexLogic timers............................................................................................................... 5-203
5.6.7 FlexElements ..................................................................................................................... 5-203
5.6.8 Non-volatile latches.......................................................................................................5-207
5.7 Grouped elements............................................................................................. 5-208
5.7.1 Overview ............................................................................................................................. 5-208
5.7.2 Setting group 1................................................................................................................. 5-208
5.7.3 Line differential elements............................................................................................ 5-209
5.7.4 Phase current ................................................................................................................... 5-214
5.7.5 Neutral current................................................................................................................. 5-226
5.7.6 Ground current ................................................................................................................ 5-234
5.7.7 Negative sequence current........................................................................................ 5-237
5.7.8 Breaker failure (ANSI 50BF)......................................................................................... 5-239
5.7.9 Voltage elements ............................................................................................................ 5-249
5.7.10 Supervising elements.................................................................................................... 5-256
5.8 Control elements ............................................................................................... 5-259
5.8.1 Overview ............................................................................................................................. 5-259
5.8.2 Trip bus ................................................................................................................................ 5-259
5.8.3 Setting groups .................................................................................................................. 5-261
5.8.4 Selector switch................................................................................................................. 5-262
5.8.5 Underfrequency (ANSI 81U)........................................................................................ 5-269
5.8.6 Frequency rate of change (ANSI 81R).................................................................... 5-270
5.8.7 Synchrocheck (ANSI 25) ............................................................................................... 5-272
5.8.8 Autoreclose (ANSI 79).................................................................................................... 5-278
5.8.9 Digital elements............................................................................................................... 5-284
5.8.10 Digital counters................................................................................................................ 5-287
5.8.11 Monitoring elements ..................................................................................................... 5-289
5.9 Inputs/outputs ................................................................................................... 5-304
5.9.1 Contact inputs.................................................................................................................. 5-304
5.9.2 Virtual inputs..................................................................................................................... 5-306
5.9.3 Contact outputs............................................................................................................... 5-307
5.9.4 Virtual outputs.................................................................................................................. 5-310
5.9.5 Resetting ............................................................................................................................. 5-310
5.9.6 Direct inputs and outputs ........................................................................................... 5-311
5.10 Transducer inputs/outputs.............................................................................. 5-313
5.10.1 DCmA inputs...................................................................................................................... 5-313
5.10.2 RTD inputs .......................................................................................................................... 5-314
5.10.3 DCmA outputs .................................................................................................................. 5-315
5.11 Testing................................................................................................................. 5-319
5.11.1 Test mode function ........................................................................................................5-319
5.11.2 Test mode forcing........................................................................................................... 5-319
5.11.3 Phasor Measurement Unit test values.................................................................. 5-320
5.11.4 Force contact inputs ..................................................................................................... 5-321
5.11.5 Force contact outputs .................................................................................................. 5-321
5.11.6 Channel tests .................................................................................................................... 5-322