Woodward SEG HighPROTEC MRA4, Руководство по эксплуатации устройства, Страница: 417 / 510

AR-Protection Module – Automatic Reclosure [ANSI 79]
Starting the dead time
If the Off-command is given out to the CB and the device can clearly detect within the start time the OFF position
of the CB (that means CB P
OS
O
N
= false and CB P
OS
O
FF
= true) then the dead time(r) will be started.
Dead time (»AR.t-dead«)
The AR module waits for the dead time to finish. When this time has elapsed it is checked if the CB is still
in OFF-position and if the CB is ready for reclosing (e.g. Function: CB ready?). Additionally it is checked
whether another trip exists and if the synchronization signal is active (option) before the reclosing
command is actually issued. If the result of the check is negative this puts the AR in the »A
R
.
T
-S
UPERV
«
state; the AR is being blocked for this time.
For phase and earth faults or for a start from external trips individual dead times can be parameterized.
When trips are caused by phase fault or external trips via digital inputs the dead time »t DPn« is always
used (the letter »n« stands for the number of the present AR shot).
When trips are caused by faults in the grounding system the dead time »t DEn« is always used (the letter
»n« stands for the number of the present AR shot).
Dead time is expired – issuing the CB on command
If the dead time has expired the CB on command is issued to the circuit breaker if:
•
No active blocking
•
The circuit breaker is ready for operation.
•
There is no pending trip command of an AR authorized protection function.
•
The CB is clearly in the OFF position that means CB P
OS
O
N
= false and CB P
OS
O
FF
= true.
•
If a synchronous check is parameterized, the device must recognize the Sync-Signal during t-sync is
running.
If all the pre-conditions are fulfilled the CB on command will be given out at most as long as » t-CB on Cmd« . The
command will be terminated if the CB is clearly in the ON position that means CB P
OS
O
N
= true and CB P
OS
O
FF
= false. The counters are incremented.
Test – Was the auto reclosure attempt successful?
The reclosure attempt has been successful if and only if:
1. Not later than the » t-CB On Cmd« timer has expired the CB is clearly in the ON-position that means CB
P
OS
O
N
= true and CB P
OS
O
FF
= false.
2. Within the supervision time no new alarm/trip, caused by an AR-authorized protection function, occurs
(otherwise the AR-cycle will be aborted).
3. The AR-module is not aborted by any blocking or abort signal.
If an alarm/trip is generated by an AR authorized protection function while
the supervision/discrimination timer runs down the AR-module is put back
into the state AR ready if and only if the maximum number of AR-cycles is
not reached yet. Otherwise the AR will be broken up/stopped and the signal
»AR.
FAILED
« will be given out.
EN MRA4 04/09 Page 417