Areva MiCOM P125, Technical Manual

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Application Guide P12y/EN AP/D32
MiCOM P125/P126 & P127 Page 39/74
5. Reclaim Time tR
When the tD timer is expired, a close command is launched to the CB by an output
relay, the reclaim time (
tR
) will begin to count when the 52a input will be energized. It
will mean that the CB is closed.
When the close command is launched the tClose Pulse timer begins to count too. This
timer takes a look to the change of the 52a status from low to high, if the timer expired
before changing of the 52a, a time out condition has occurred and the ARC function
will move to the locked status. Otherwise the timer will be reset and the ARC will
continue with the setting cycles.
The setting for the t Close Pulse timer is available in the Automatic Control CB
Supervision submenu.
If during the tR the 52a will change status from high to low (CB from close to open
status), the ARC will move to the lock status.
If none phase or earth current threshold, earth power threshold or external digital input
will trip within the reclaim time, at the expiring of tR, the autoreclose function resets to
the initial status ready to re-start for a new cycles sequence.
6. Inhibit Time tI
The Inhibit time starts when an intentional closing action is executed on the CB. Any
trip opening the CB within the tI timer will move the ARC in the lock status. The setting
value of the
Inhibit Time (tI)
can be used to prevent autoreclose being initiated when
the CB is manually closed onto a fault.
7. Phase and earth fault cycles number
The maximum available auto-recloser cycles in the ARC in the P126 and P127 are 4.
The user can set 4 cycles for the earth faults and 4 cycles for the phase faults or
other. The auto-recloser algorithm will execute a maximum of 4 cycles.
What does it mean?
It means, for instance, we have set 4 auto-recloser cycles for earth fault and 4 auto-
recloser cycles for phase fault.
During a fault situation we have already executed 2 autoreclose cycles for a phase
fault, if the next fault will be an earth fault the ARC will be able to execute the
remaining ones. The number of set cycles, earth and/or phase, must be in accordance
with the set of the ARC configuration matrix setting. The setting to 0 of the phase
cycles and/or the earth cycles means that any trip of phase or earth are considered
final trip. The autoreclose will move in the lock status.
8. ARC configuration matrix
From the 6A software version it has been implemented the possibility to assign to any
phase current threshold, to any earth fault current/power threshold and to the tAux1
and tAux2 the cycle where to have a recloser action or a definitive trip or a trip without
the relevant activation of the relay 1. The listed table below shows the involved
thresholds and the relevant setting way.