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6.38
SEL-400 Series Relays
Instruction Manual
Date Code 20171006
Autoreclosing
Autoreclose Logic Diagrams
Figure 6.16
Two Circuit Breakers Three-Pole Cycle State (79CY3) When E79 := Y1
12
3
6
9
12
3
6
9
79CY3
79CY3
Yes
No
No
LEADBKR Closed
(by external means)
Close
Supervision
Delay (BKnCLSD)
Is Skip Shot
Asserted?
Has the Line
Opened 3 Pole?
Increment Shot.
Is Shot Count Greater
Than or Equal to the
Number of set Reclosures?
Breaker Close
Failure Timer (BKCFD)
Is Leader Allowed
to Close (3PnCLS)?
Is Leader Closed?
Issue Leader
CLOSE Command
Yes
No
Yes
Timing
12
3
6
9
No
Timing
Timed Out, or 3-Pole Reclosing
Disabled for Lead Breaker (E3PRn=0)
Timed
Out
LBKCL
C
A
Determine Active
Breakers in Scheme
NBK2
NBK1
Lockout
(BKnLO)
A
Freeze
3PARC
3-Pole Reclose Initiation (3PARC)
from Ready States (BK1RS and/or
BK2RS) or from Single-Pole Reclose
Cycle State (79CY1)
3-Pole Reclose Initiation (3PARC)
while in 3-Pole Reclose Cycle
State (79CY3)
If 3-Pole Reclosing is disabled for Breaker n (E3PRn = 0), send
Breaker n to lockout (BKnLO). Recalculate Leader, Follower, and
Number of Active Breakers logic, then freeze calculations
Yes
(3PLSHT)
Lockout
(BKnLO)
3PRIH
Timeout
12
3
6
9
3PRIH = OFF
Timed Out
3 Pole Open Interval
Timer (3POIDn)
Is Leader Open?
Yes
No
Yes
12
3
6
9
Yes
No
Timing
Timed Out
(BKnLO)
Is 3-Pole Open Interval
Supervision (3POISC)
Satisfied?
3POLINE
Note: If BKnCLSD = OFF, the timer is disabled, and
requires 3pnCLS to assert before issuing a Leader
Breaker CLOSE command.
Summary of Contents for SEL-421-4
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