2 Functions
140
7SD610 Manual
C53000-G1176-C145-4
The detection of an evolving fault can be defined under address 3406 EV. FLT.
RECOG.. EV. FLT. RECOG. with PICKUP means that, during a dead time, every
pickup of a protective function will be interpreted as an evolving fault. With EV. FLT.
RECOG. with TRIP a fault during a dead time is only interpreted as an evolving fault
if it has led to a trip command by a protection function. This may also include trip com-
mands which are coupled in from external via a binary input or which have been trans-
mitted from an opposite end of the protected object. If an external protection device
operates together with the auto-reclosure, evolving fault detection with pickup presup-
poses that a pickup signal from the external device is also connected to the 7SD610;
otherwise an evolving fault can only be detected with the external trip command even
if with PICKUP was set here.
The reaction in response to sequential faults can be selected at address 3407. EV.
FLT. MODE Stops AutoRecl means that no reclosure is performed after detection
of a sequential fault. This is always useful when only single-pole reclosure is to take
place or when stability problems are expected due to the subsequent three-pole dead
time. If a three-pole reclose cycle is to be initiated by tripping of the sequential fault,
set EV. FLT. MODE = starts 3p AR. In this case a separately adjustable three-
pole dead time is started with the three-pole trip command due to the sequential fault.
This is only useful if three-pole reclosure is also permitted.
Address 3408 T-Start MONITOR monitors the reaction of the circuit breaker after a
trip command. If the CB has not opened during this time (from the beginning of the trip
command), the automatic reclosure is blocked dynamically. The criterion for circuit
breaker opening is the position of the circuit breaker auxiliary contact or the disappear-
ance of the trip command. If a circuit breaker failure protection (internal or external) is
used on the feeder, this time should be shorter than the delay time of the circuit
breaker failure protection so that no reclosure takes place if the circuit breaker fails.
Note
If the breaker failure protection (BF) is to perform a single-pole TRIP repetition, the
time setting of parameter 3408 T-Start MONITOR must be longer than the time set
for parameter 3903 1p-RETRIP (T1).
To enable that the busbar is tripped by the breaker failure protection without preceding
three-pole coupling of the trip command (by AR or BF), the time set for 3408 T-Start
MONITOR also has to be longer than the time set for 3906 T2. In this case, the AR
must be blocked by a signal from the BF to prevent the AR from reclosing after a
busbar TRIP. It is recommended to connect the signal 1494 „BF T2-TRIP(bus)“ to
the AR input 2703 „>AR block“ by means of CFC.
If the reclosure command is transmitted to the opposite end, this transmission can be
delayed by the time setting in address 3410 T RemoteClose. This transmission is
only possible if the device operates with adaptive dead time at the remote end
(ad-
dress 133 Auto Reclose = ADT). This parameter is otherwise irrelevant. On the one
hand, this delay serves to prevent the remote end device from reclosing unnecessarily
when local reclosure is unsuccessful. On the other hand, it should be noted that the
line is not available for energy transport until the remote end has also closed. This
delay must therefore be added to the dead time for consideration of the network sta-
bility.
Configuration of
auto-reclosure
This configuration concerns the interaction between the protection and supplementary
functions of the device and the auto reclose function. The selection of device functions
which are to start the automatic reclosure circuit and which are not to, is made here.
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