Siemens SIPROTEC 7SD80 Manual page 149

The options for handling evolving faults are described in Section 2.11 under margin heading „Handling Evolving
Faults". You can define recognition of an evolving fault at address 3406 EV. FLT. RECOG.. EV. FLT.
RECOG.with PICKUP means that during a dead time each pickup of a protection 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 commands
which are received from an external device via a binary input or which have been transmitted from another end
of the protected object. If an external protection device operates together with the internal auto-reclosure,
evolving fault detection with pickup presupposes that a pickup signal from the external device is also connected
to the 7SD80; otherwise an evolving fault can only be detected with the external trip command even if with
PICKUP was set here.
The reaction to evolving faults can be selected under address 3407. EV. FLT. MODE Stops 79 means that
no reclosing takes place after detection of an evolving fault. This is recommended if stability problems are an-
ticipated when reclosing after the 3-pole dead time. If a 3-pole reclose cycle is to be initiated by tripping of the
evolving fault, set EV. FLT. MODE = starts 3p AR. In this case, a separately adjustable 3-pole dead time
is started with the trip command due to the evolving fault.
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 disappearance 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 time delay of the circuit-breaker failure protection so that no
reclosure takes place if the circuit breaker fails.
Note
To enable that the busbar is tripped by the breaker failure protection without preceding injection 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 50BF-2 Delay. 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 „50BF BusTrip" to the AR input
2703 „>BLOCK 79" via CFC.
Configuring the Automatic Reclose Function
This configuration concerns the interaction between the protection and supplementary functions of the device
and the automatic reclosure function. The selection of functions of the device which are to start the automatic
reclosure circuit and which are not to, is made here.
Address 3420
Address 3423
Address 3424
Address 3425
For the functions which are to start the auto-reclosure function, the corresponding address is set to YES, for the
others to NO. The other functions cannot start the automatic reclosure because reclosure is of little use here.
First Reclosing Cycle
Address 3450 1.AR:START is only available if the automatic reclosing function works in the operating mode
with action time, i.e. address 134 AR control mode = PU w/ActionTime or Trip w/ActionT. was set
during configuration of the protection functions (see Section 2.1.1.2). It determines whether the automatic re-
closing function is started with the first cycle. This parameter and different action times allow you to control the
effectiveness of the cycles (AR control mode = Trip ....).
SIPROTEC, 7SD80, Manual
E50417-G1140-C474-A1, Release date 09.2011
AR WITH DIFF, i.e. with differential protection
AR w/ INT.TRIP, i.e. with permissive underreach transfer trip (PUTT)
AR w/ DTT, i.e. with direct transfer trip
AR w/ 50(N)-B, i.e. with time overcurrent protection
2.11 Automatic Reclosure Function 79 (Optional)
Functions
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