Schweitzer Engineering Laboratories SEL-421-4 - Page 512

6.176
SEL-421 Relay Instruction Manual Date Code 20171021
Protection Applications Examples
230 kV Tapped Transmission Line Application Example
Protection Freeform SELOGIC Control Equations
FBKCEN Follower Breaker Closing Enable (SELOGIC) 52AA1
ULCL1 Unlatch Closing for Breaker 1 (SEL
OGIC) 52AA1
ULCL2 Unlatch Closing for Breaker 2 (SEL
OGIC) 52AA2
79DTL Recloser Drive to Lockout (SEL
OGIC)NA
79BRCT Block Reclaim Timer (SEL
OGIC)NA
BK1CLSD BK1 Reclose Supervision Delay (cycles) 1200
BK2CLSD BK2 Reclose Supervision Delay (cycles) 1200
Three-Pole Reclose Settings (Group)
3POID1 Three-Pole Open Interval 1 Delay (cycles) 300
3PFARC Three-Pole Fast ARC Enable (SEL
OGIC)NA
3PRCD Three-Pole Reclaim Time Delay (cycles) 1200
3PRI Three-Pole Reclose Initiation (SELOGIC) Z1P OR Z1G OR
RXPRM
79SKP Skip Reclosing Shot (SEL
OGIC)NA
3P1CLS Three-Pole BK1 Reclose Supervision (SEL
OGIC) PCT01Q
3P2CLS Three-Pole BK2 Reclose Supervision (SEL
OGIC) PCT02Q
Trip Logic
a
TR Zone 1 direct transfer trip RMB2A OR RMB2B
OR
Step-distance or time-overcurrent protection Z1T OR Z2T OR 51S1T
OR
Direct transfer trip if MOD closed (RMB3A OR RMB3B)
AND NOT IN103…
a
This portion of the table shows all of the receive MIRRORED BITS (RMB n ) communications
assignments.
Table 6.47 Group Settings (Sheet 2 of 2)
Setting Prompt Entry
Table 6.48 Protection Freeform SELOGIC Control Equations (Sheet 1 of 2)
Setting Description Entry Comments
PSV01 Protection Comparison 1 PSV01 := V1M >= 119.500 Logical 1 if V1 greater than or equal to
90% nominal voltage
PSV02 Protection Comparison 2 PSV02 := V1M < 26.500 Logical 1 if V1 is less than 20% nominal
voltage
PLT01S Protection Latch 1 set PLT01S := R_TRIG PST02Q AND
NOT PLT01
MOD latch set
PLT01R Protection Latch 1 reset PLT01R := R_TRIG PST03Q AND
PLT01
MOD latch reset
PST01PT Protection Sequence Timer 1 preset PST01PT := 150.00 Pulse open the MOD if:
PST01R Protection Sequence Timer 1 reset PST01R := NOT PSV02 OR NOT
IN101 OR NOT IN102 OR PST01Q OR
IN103
230 kV bus is not dead OR BK1T OR
BK2T is closed OR PST01 output
equals logical 1 OR MOD is open
PST01IN Protection Sequence Timer 1 enable PSTO1IN := PSV02 AND IN101 AND
IN102 AND NOT IN103
230 kV bus is dead AND BK1T AND
BK2T are open AND MOD is closed
OUT103
a
Output 103 PST01ET > 120.00 AND NOT PCN01Q MOD open command
PST02PT Protection Sequence Timer 2 preset PST02PT := 780.00 MOD latch is set if: