Figure 3.22-6 79AR block instantaneous protection
3.22.2.4 AR Reclosing
When a new shot is initialized, the AR is in process. The AR contains two types of start commands
at the first shot: high speed or time delayed startup signal (such as: By instantaneous or time delay
units of overcurrent relay startup). The starting signal determines whether a high speed or delay
recloses and time delay required for each reclose, until the final tripping is made.
For the first shot, if AR is activated by input 79AR_TripH, the dead time is 79AR_T_DeadTimeH
without synchro check, if AR is activated by input 79AR_Trip, the dead time is
79AR_T_DeadTime1, another shots dead time are 79AR_T_DeadTime2, 79AR_T_DeadTime3
and 79AR_T_DeadTime4 separately.
Except the high speed startup, the synchro check condition is judged by settings 79_Sync_Ena.
When the dead time delay of AR expires after AR is initiated, if the setting 79_Sync_Ena=1, the
release of reclosing command shall be subject to the result of synchronism check. After the dead
time delay of AR expires, if the synchronism check is still unsuccessful within the time delay
79AR_T_WaitSyn, the signal of synchronism checks failure 79AR_ChkFail will be output and the
AR will be blocked. If the setting 79_Sync_Ena=0, the condition of synchronism checks success
25SYN_Chk_OK will always be established. And the signal of synchronism checks success
25SYN_Chk_OK from the synchronism check logic can be applied by auto-reclosing function
inside the device or external synchronism device.
If a circuit breaker close command is given successfully at the end of the dead time, a reclaim time
starts. The reclosing pulse length may be set through the setting 79AR_T_Pluse. If the circuit
breaker does not trip again within reclaim time setting 79AR_T_Reclaim, the AR indicates a
successful reclosing and resets into "ready" status. If the protection trips again during the setting
79AR_T_Reclaim, the sequence advances to the next shot. If all reclosing attempts have been
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