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b) Sufficient energy available to fully close the breaker
c) No protection trip is active and
d) Non recloser mode is not active
The close signal is a fixed pulse output. In addition, the reclaim timer will start at the end
of reclose time. The reclaim time is set by Reclaim time. If the network fault is cleared (i.e.
no new trip signal received) during reclaim time, the auto-recloser is successful and
function will reset to quiescent condition.
In case before the elapsing of dead time t1, if circuit breaker is detected to be in closed
position OR any trip signal is received (by any of the protection function i.e. 51P-1, 51P-2
& 51P-3), function will activate FINAL TRIP and will disable the AR sequence.
Duration of FINAL TRIP output will be of 200ms.
However, if the network fault is not cleared, i.e. auto-recloser is unsuccessful, and the
protection based on AR initiation matrix trips the breaker before expiration of the reclaim
time, the next shot will be initiated (depending upon allowable AR operation set using
Number of reclose attempts setting). At the time of shot initiation, the set dead time t2 will
start.
In this way Auto reclosing sequence continues until the set Number of reclose attempts.
Auto reclose will remain in blocked condition for Auto Recloser Block time
when CB is closed from HMI or by communication to ensure non reclosing
of CB during SOTF condition.
If NRM is activated and CB is open, then auto recloser is deactivated and
no further closing of CB is allowed until NRM mode is disabled.
Once function enters into block mode it remains in blocked mode for time set equal to
Auto Reclose Block time.
In case CB close does not happens after issuing a reclosing command within set Reclaim
time, then AR goes to blocked mode.
Auto Recloser initiation Matrix
Auto reclose initiation matrix defines which protection function should initialize different
auto reclosing shots. In addition, it also defines the behavior of the function after that
particular shot is finished. The matrix defined will be as shown below:
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