Sel SEL-421 - One Circuit Breaker Three-Pole Cycle State (79 CY3)

R.2.31
Date Code 20111215 Reference Manual SEL-421 Relay
Auto-Reclosing and Synchronism Check
Auto-Reclose Logic Diagrams
Figure 2.11 One Circuit Breaker Three-Pole Cycle State (79CY3)
12
3
6
9
12
3
6
9
12
3
6
9
12
3
6
9
Is Breaker
Open 3 Pole?
(3POLINE = 1?)
to Beginning
of 79CY3
Reset State
(BK1RS)
79CY3
79CY3
Lockout
(BK1LO)
Lockout
(BK1LO)
3PARC
Is Breaker
Allowed to Close?
(3P1CLS=1?)
Is Block Reclaim
Time (79BRCT) Asserted?
Did Breaker Close?
Yes
Yes
Timed
Out
Timed
Out
Timed Out
Breaker Open
Close
Supervision Delay
Three-Pole Open
Interval Timer
(3POIDn)
No
Timing
BK1CL
No
Timing
Yes
3PARC
Timing
Breaker Close
Failure Timer (BKCFD)
Three-Pole
Reclaim Timer
(3PRCD)
(BK1CLSD)
No
Yes
3POLINE
Increment Shot Counter
and Issue CLOSE Command
3PARC
No
Lockout
(BK1LO)
Note:
If 3POLINE does not
assert (three-pole
breaker does not
open), the auto-reclose
cycle state will remain
in the check for the
3POLINE = 1 condition
indefinitely, or until
the 79DTL logic
(Drive to Lockout)
Relay Word bit asserts.
In applications where
the 3POLINE Relay Word
bit may not reliably
assert at this point,
we recommend using
logic in the 79DTL
setting to bypass this
stall condition after
a fixed time delay.
Timed Out