ABB Relion 670 Series Technical Reference Manual page 27

Technical reference manual
Function block.................................................................................806
Input and output signals..................................................................806
Setting parameters..........................................................................807
Technical data.................................................................................808
Local acceleration logic ZCLCPLAL.....................................................808
Introduction......................................................................................808
Principle of operation.......................................................................808
Zone extension...........................................................................808
Loss-of-Load acceleration..........................................................809
Function block.................................................................................810
Input and output signals..................................................................810
Setting parameters..........................................................................811
Scheme communication logic for residual overcurrent protection
ECPSCH (85).......................................................................................811
Introduction......................................................................................811
Principle of operation.......................................................................812
Blocking scheme........................................................................812
Permissive under/overreaching scheme....................................813
Unblocking scheme....................................................................815
Function block.................................................................................816
Input and output signals..................................................................816
Setting parameters..........................................................................817
Technical data.................................................................................817
Current reversal and weak-end infeed logic for residual
overcurrent protection ECRWPSCH (85).............................................817
Introduction......................................................................................818
Principle of operation.......................................................................818
Directional comparison logic function.........................................818
Fault current reversal logic.........................................................819
Weak-end infeed logic................................................................819
Function block.................................................................................821
Input and output signals..................................................................821
Setting parameters..........................................................................822
Technical data.................................................................................822
Current reversal and weak-end infeed logic for phase segregated
communication ZC1WPSCH (85).........................................................822
Introduction......................................................................................823
Principle of operation.......................................................................823
Current reversal logic ................................................................823
Function block.................................................................................825
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