Schweitzer Engineering Laboratories SEL-321 - Page 22

ii Specifications Date Code 20011026
SEL-321/321-1 Instruction Manual
Relay Elements ...................................................................................................................2-23
Trip Logic ................................................................................................................................... 2-37
Selecting Single-Pole or Three-Pole Tripping Logic..........................................................2-38
Tripping Output Signals......................................................................................................2-38
Single-Pole Tripping Conditions ........................................................................................2-38
Selecting Elements to Trip.................................................................................................. 2-38
MTU (Unconditional Trip Variable) ..........................................................................2-38
MTO (Switch-Onto-Fault Trip Variable) ...................................................................2-39
MTCS (Communications-Scheme Trip Variable) ......................................................2-39
Unlatch Logic Selections ....................................................................................................2-39
Multiple Setting Groups .............................................................................................................2-39
Active Groups and Group Variables...................................................................................2-40
Global Settings....................................................................................................................2-40
Metering......................................................................................................................................2-40
System Frequency Tracking .......................................................................................................2-40
Fault Locator...............................................................................................................................2-40
Front-Panel Targets ....................................................................................................................2-41
General Target LED Description........................................................................................2-41
Communications Ports Specifications ........................................................................................ 2-44
Internal Time Clock Time-Code Synchronization Specifications ......................................2-45
Self-Tests ....................................................................................................................................2-45
Technical Specifications (1 A Nominal Relay)..........................................................................2-47
General Element Ranges and Accuracy..............................................................................2-47
Technical Specifications (5 A Nominal Relay)..........................................................................2-49
General Element Ranges and Accuracy..............................................................................2-49
General Specifications................................................................................................................ 2-51
Distance Element Operating Time Curves at Nominal Frequency.............................................2-79
Time-Overcurrent Curve Equations............................................................................................2-80
Equations for US Curves ....................................................................................................2-81
Equations for IEC Curves ................................................................................................... 2-82
TABLES
Table 2.1: Relay Setting Structure............................................................................................................2-1
Table 2.2: Zone and Level Elements Affected by DIR1 - DIR4 ..............................................................2-2
Table 2.3: Trip Coil Monitor Logic Input Assignment Options.............................................................2-17
Table 2.4: Logic Input Assignment List .................................................................................................2-19
Table 2.5: Unacceptable SELOGIC Control Equation Operator Combinations......................................2-23
Table 2.6: Front-Panel Status Indicators ................................................................................................2-23
Table 2.7: Primary Elements ..................................................................................................................2-24
Table 2.8: Primary Element Summary....................................................................................................2-24
Table 2.9: Assigned Input Statuses.........................................................................................................2-28
Table 2.10: Intermediate Elements .........................................................................................................2-29
Table 2.11: Intermediate Element Summary ..........................................................................................2-29
Table 2.12: Internal Elements.................................................................................................................2-29
Table 2.13: Internal Element Summary ..................................................................................................2-30
Table 2.14: Input/Output Contact Targets (One I/O Board Version, SEL-321 Relay Only) .................2-32
Table 2.15: Input/Output Contact Targets (Two I/O Board Version, SEL-321 Relay Only).................2-32
Table 2.16: Remote Bits (SEL-321-1 Relay Only).................................................................................2-32