Sel SEL-421 - Two Circuit Breakers Single-Pole Cycle State (79 CY1) When E79:= Y1

R.2.34
SEL-421 Relay Reference Manual Date Code 20111215
Auto-Reclosing and Synchronism Check
Auto-Reclose Logic Diagrams
Figure 2.13 Two Circuit Breakers Single-Pole Cycle State (79CY1) When E79 := Y1
Has Leader or Follower
Opened Single Pole?
12
3
6
9
12
3
6
9
12
3
6
9
SPARC
79CY3
79CY1
79CY1
Timed Out
Single Pole
Interval Timer (SPOID)
Close
Supervision
Delay (BKnCLSD)
Freeze Leader, Follower,
and NBKn Calculations
Does Leader Have
a Single Pole Open?
Does Follower
Have Single Pole Open?
Does Follower
Have Single Pole Open?
Issue Leader
CLOSE Command
Did Leader Close?
Determine Active
Breakers in Scheme
Determine Active
Breakers in Scheme
Is Leader Allowed
to Close (SPnCLS)?
To Reclaim Stage
Timed Out
No
No
No
No
NBK1
Yes
3PARC
Yes
No
Timing
NBK2
Timing
Breaker Close
Failure Timer (BKCFD)
Time Between
Breakers (TBBKD)
Timed
Out
Yes
Yes
Yes
Yes
LBKCL
NBK1
Send Leader
to Lockout (BKnLO)
NBK2
C
A
A
B
Lockout
(BKnLO)
12
3
6
9
SPARC
79CY3
3PARC
Timed
Out
To Beginning
of 79CY1
Recalculate NBKn,
Leader, and Follower
No