Sel SEL-421 - Page 5

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Date Code 20020501 SEL-421/SEL-421-1 Relay
Table of Contents
Section 6: SEL-2030 Applications
SEL Communications Processor ................................................................................................................. A.6.2
SEL-2030 and SEL-421 Relay Architecture ............................................................................................... A.6.4
SEL-2030 Example ..................................................................................................................................... A.6.6
Section 7: Direct Network Communication
Direct Network Communication ................................................................................................................. A.7.2
Serial Networking........................................................................................................................................ A.7.3
SEL-2701 Ethernet Processor...................................................................................................................... A.7.5
Direct Networking Example........................................................................................................................ A.7.7
Reference Manual
Section 1: Protection Functions
Current and Voltage Source Selection..........................................................................................................R.1.2
Frequency Estimation.................................................................................................................................R.1.10
Fault Location.............................................................................................................................................R.1.11
Open Phase Detection Logic ......................................................................................................................R.1.13
Pole Open Logic.........................................................................................................................................R.1.14
LOP Logic ..................................................................................................................................................R.1.16
FIDS Logic .................................................................................................................................................R.1.20
Ground Directional Element.......................................................................................................................R.1.21
Phase and Negative-Sequence Directional Elements.................................................................................R.1.33
Directionality..............................................................................................................................................R.1.35
CVT Transient Detection............................................................................................................................R.1.36
Series-Compensation Line Logic ...............................................................................................................R.1.38
Load-Encroachment Logic .........................................................................................................................R.1.39
OOS Logic..................................................................................................................................................R.1.41
Mho Ground Distance Elements ................................................................................................................R.1.46
Quadrilateral Ground Distance Elements...................................................................................................R.1.51
Mho Phase Distance Elements ...................................................................................................................R.1.55
Zone Time Delay ........................................................................................................................................R.1.59
Instantaneous Line Overcurrent Elements..................................................................................................R.1.62
Inverse Time-Overcurrent Elements ..........................................................................................................R.1.69
SOTF Logic................................................................................................................................................R.1.85
Communications-Assisted Tripping Logic.................................................................................................R.1.88
DCB Scheme ..............................................................................................................................................R.1.89
POTT Scheme ............................................................................................................................................R.1.93
DCUB Scheme Logic.................................................................................................................................R.1.99
Trip Logic .................................................................................................................................................R.1.103
Circuit Breaker Failure Protection............................................................................................................R.1.112
Section 2: Auto-Reclose and Synchronism Check
Auto-Reclose ................................................................................................................................................R.2.2
One-Circuit-Breaker Recloser......................................................................................................................R.2.5
Two-Circuit-Breaker Recloser....................................................................................................................R.2.11
Voltage Checks ...........................................................................................................................................R.2.27
Relay Settings and Relay Word Bits...........................................................................................................R.2.29
Synchronism Check....................................................................................................................................R.2.41