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6.19
Date Code 20171006
Instruction Manual
SEL-400 Series Relays
Autoreclosing
Two-Circuit-Breaker Autoreclosing
Block Reclosing With Enable Settings
To block BK2 as leader use the enable settings; set ESPR2 := NBK2 and
E3PR2 := NBK2. With these enable settings BK2 never becomes the leader cir-
cuit breaker.
Example Two: BK2 as Successful Follower and Dynamic Leader
Another example is similar to the first with SLBK1/SLBK2/FBKCEN at 1/0/1
(see
Reset State
Prior to receiving initiation for a three-phase fault, the autoreclose logic resets for
both circuit breakers. At the start of the reclose cycle, Relay Word bits
LEADBK1, FOLBK2, and NBK2 are asserted (see
Table 6.9
Example One: Reset State After Reclaim Time
Relay Word Bit
Description
Logical State
NBK0
No Active Breakers in Reclose Scheme
0
NBK1
One Breaker Active in Reclose Scheme
1
NBK2
Two Active Breakers in Reclose Scheme
0
LEADBK0
No Leader Breaker
0
LEADBK1
Leader Breaker = Breaker 1
0
LEADBK2
Leader Breaker = Breaker 2
1
FOLBK0
No Follower Breaker
1
FOLBK1
Follower Breaker = Breaker 1
0
FOLBK2
Follower Breaker = Breaker 2
0
Table 6.10
Leader/Follower Selection
Setting Label
Value
SLBK1
1
SLBK2
0
FBKCEN
1
Table 6.11
Example Two: Initial Reset State
Relay Word Bit
Description
Logical State
NBK0
No Active Breakers in Reclose Scheme
0
NBK1
One Breaker Active in Reclose Scheme
0
NBK2
Two Active Breakers in Reclose Scheme
1
LEADBK0
No Leader Breaker
0
LEADBK1
Leader Breaker = Breaker 1
1
LEADBK2
Leader Breaker = Breaker 2
0
FOLBK0
No Follower Breaker
0
FOLBK1
Follower Breaker = Breaker 1
0
FOLBK2
Follower Breaker = Breaker 2
1
Summary of Contents for SEL-421-4
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