P54x/EN OP/La4 Operation
(OP) 5-196
MiCOM P543, P544, P545 & P546
OP
5.6.6.12 Reclaim time & successful auto-reclose (P544/P546)
The reclaim time logic is shown in AR Figure 34 and Figure 35 (logic diagram supplement).
The succe
ssful auto-reclose logic is shown in AR Figure 36, Figure 37 and Figure 38
(logi
c diagram supplement).
The Set CB1 Close & Set CB1 Close, DDBs (1565/1449) signals from the auto close logic
are used to enable the reclaim timers. Depending on whether the circuit breaker has tripped
single phase or three phase, and whether single phase and/or three phase reclosing is
permitted for the circuit breaker, either the single phase reclaim timer SPAR Reclaim Time
or the three phase reclaim timer 3PAR Reclaim Time is enabled.
If any protection re-operates before the reclaim time has timed out, the sequence counter is
incremented. The counter signal advances from ‘Seq Counter = n’ to ‘Seq Counter = (n+1)’,
resets any ….DTCOMP signal and prepares the logic for the next dead time to start when
conditions are suitable. The operation also resets the Set CB Close signal, and hence the
reclaim timer is also stopped and reset. The Reclaim time starts again if the Set CB Close
signal goes high following completion of a dead time in a subsequent auto-reclose cycle.
If CB1 is closed and has not tripped again when the reclaim time is complete, signals CB1
Succ 1P AR, (DDB1571) or CB1 Succ 3P AR, (DDB 852) are generated to indicate the
successful reclosure.
Similarly, If CB2 is reclosed during the auto-reclose cycle and remains closed when the
reclaim time is complete, signals CB2 Succ 1P AR, (DDB 1451) or CB2 Succ 3P AR, (DDB
1452) are generated to indicate successful reclosure.
These signals also increment the relevant circuit breaker successful auto-reclose shot
counters and reset the relevant CB ARIP signal.
The successful auto-reclose signals generated from the logic can be reset by various
commands and settings options available under CB CONTROL menu settings column.
These settings are described below:-
If Res AROK by UI is set to enabled, all the successful auto-reclose signals can be reset
by user interface command Reset AROK Ind from the CB CONTROL settings column.
If Res AROK by NoAR is set to enabled, the successful auto-reclose signals for each
circuit breaker can be reset by temporarily generating an AR disabled signal for each circuit
breaker according to the logic described in section 5.6.6.21, Auto
reclose Enable logics, AR
Figure 5.
If Res AROK by Ext is set to enabled, the successful autoreclose signals for can be reset
by activation of the relevant input Ext Rst CB1 AROK or Ext Rst CB2 AROK (DDB1517 or
1417) mapped in the PSL.
If Res AROK by TDly is set to enabled, the successful autoreclose signals for are
automatically reset after a user defined time delay as set in Res AROK by TDly setting.
5.6.6.13 Circuit breaker healthy & system check timers (P54
4/P546)
The circuit breaker healthy and system check timers logic is shown in AR Figure 39 and
Figure 40 (logic diagram supplement).
This lo
gic provides signals to cancel auto-reclosing for either circuit breaker if the circuit
breaker is not healthy (e.g. low gas pressure or, for three phase auto-reclosing, the required
line & bus voltage conditions are not satisfied) when the scheme is ready to close the circuit
breaker.
In this logic, both CB1 and CB2 share the settings AR CBHealthy Time and AR CheckSync
Time.
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