ABB REB670 - Page 9

Differential protection..................................................................111
Check zone protection
................................................................114
Switch status monitoring
.............................................................116
CT connection control.................................................................120
CT disconnection for bus interconnector CT cores.................... 122
End fault protection.....................................................................127
Zone interconnection (Load transfer)......................................... 130
Tripping arrangements............................................................... 132
Mechanical lock-out function...................................................... 135
Contact reinforcement with heavy duty relays............................135
Trip circuit supervision................................................................135
Two-zone busbar arrangements......................................................136
General.......................................................................................136
Single busbar arrangements...................................................... 136
Single busbar arrangements with sectionalizer.......................... 137
Single busbar arrangements with bus-section breaker.............. 138
H-type busbar arrangements......................................................139
Double circuit breaker busbar arrangement............................... 141
Breaker-and-a-half busbar arrangements.................................. 143
Double busbar single breaker arrangement............................... 145
Double busbar arrangements with two bus-section breakers
and two bus-coupler breakers.................................................... 151
Combined busbar arrangements................................................ 152
Six-zone busbar arrangements....................................................... 155
General.......................................................................................155
Typical arrangement which can be covered............................... 155
Example engineering procedure.................................................157
Summation principle........................................................................ 163
Introduction.................................................................................163
Auxiliary summation CTs............................................................166
Possible ASCT connections for REB670....................................168
Main CT ratio mismatch correction.............................................169
Primary pick-up levels for summation type differential
protection ...................................................................................169
SLCE 8/ASCT characteristics for end-connection......................172
SLCE 8/ASCT characteristics for series-connection.................. 173
Section 7 Current protection..............................................................175
Directional phase overcurrent protection, four steps
OC4PTOC(51_67)................................................................................ 175
Identification.................................................................................... 175
Table of contents
Busbar protection REB670 2.2 ANSI 3
Application manual