Sel SEL-421 - Page 201

R.2.33
Date Code 20111215 Reference Manual SEL-421 Relay
Auto-Reclosing and Synchronism Check
Auto-Reclose Logic Diagrams
Figure 2.12 Two Circuit Breakers Single-Pole Cycle State (79CY1) When E79 := Y (continued)
Yes
Yes
No
No
FBKCL
Yes
Yes
FOLBKR = L/O
FOLBKR = L/O
C
A B
Is Follower Closing
Enabled (FBKCEN = 1)?
Is Leader in
Lockout State?
Is Follower Allowed
to Close (SPnCLS)?
Follower Breaker Close
Supervision Delay (BKnCLSD)
Issue Follower
CLOSE Command
Send Follower
to Lockout
Is Follower Closed?
No
Timing
Timed Out
Timed Out
Follower Breaker Close
Failure Timer (BKCFD)
Send Follower to
Lockout State
Leader to
Reclaim Stage
Lockout
(BKnLO)
12
3
6
9
No
Timing
12
3
6
9
12
3
6
9
79CY3
Is 79BRCT Asserted?
Recalculate NBKn,
Leader, and Follower
Determine
Active Breakers
Determine Leader
SPARC
Timing
SPARC
To Beginning
of 79CY1
*Send Both Breakers
to Ready State
Breaker #1
Ready State (BK1RS)
Breaker #2
Ready State (BK2RS)
No
Yes
NBK1
LEADBK1
LEADBK2
NBK2
Timed Out
Reclaim Timer
(SPRCD)
3PARC
3PARC