ABB RELION RET670 - Page 25

Application....................................................................................... 811
Blocking schemes
.......................................................................812
Delta blocking scheme
............................................................... 813
Permissive schemes...................................................................814
Intertrip scheme..........................................................................818
Setting guidelines............................................................................ 818
Blocking scheme........................................................................ 818
Delta blocking scheme............................................................... 819
Permissive underreaching scheme............................................ 819
Permissive overreaching scheme...............................................819
Unblocking scheme.................................................................... 819
Intertrip scheme..........................................................................820
Phase segregated scheme communication logic for distance
protection ZC1PPSCH (85).................................................................. 820
Identification.................................................................................... 820
Application....................................................................................... 820
Blocking scheme........................................................................ 822
Permissive schemes...................................................................822
Intertrip scheme..........................................................................824
Setting guidelines............................................................................ 824
Permissive underreache scheme............................................... 825
Permissive overreach scheme................................................... 825
Blocking scheme........................................................................ 825
Intertrip scheme..........................................................................825
Current reversal and Weak-end infeed logic for distance protection
3-phase ZCRWPSCH (85)....................................................................826
Identification.................................................................................... 826
Application....................................................................................... 826
Current reversal logic................................................................. 826
Weak-end infeed logic................................................................ 827
Setting guidelines............................................................................ 828
Current reversal logic................................................................. 828
Weak-end infeed logic................................................................ 828
Current reversal and weak-end infeed logic for phase segregated
communication ZC1WPSCH (85)......................................................... 829
Identification.................................................................................... 829
Application....................................................................................... 829
Setting guidelines............................................................................ 831
Scheme communication logic for residual overcurrent protection
ECPSCH (85)....................................................................................... 832
Table of contents
Transformer protection RET670 2.2 ANSI 19
Application manual