Siemens siprotec 7SA6 User Manual page 459

Breaker Tripping
Alarm Suppression
7SA6 Manual
C53000-G1176-C133-1
Only once the cause for the protection operation is known, should the lock-out be reset
by a manual reset via binary input "!/RFNRXW 5(6(7" (FNo ).
"'$
FNo
>LOCKOUT Set
"'%
FNo
>LOCKOUT Reset
Figure 6-143 Trip circuit seal-in (reclosure lock-out)
The conditions which cause reclosure lock-out and the control commands which have
to be locked can be set individually. The two inputs and the output can be wired via
the correspondingly allocated binary inputs and outputs or be linked via user-defined
logic functions (CFC).
If, for example, each trip by the protection function should be sealed, then combine the
tripping command "5HOD\ 75,3" (FNo ) with the binary input "!/RFNRXW 6(7".
If automatic reclosure is applied, only the final trip of the protection function should
establish closing lock-out. Then combine the output alarm "'HILQLWLYH 75,3" (FNo
) with the lock-out input "!/RFNRXW 6(7", so that the lock-out function is not
established when an automatic reclosure is still expected to come.
In the most simple case the output alarm "/2&.287" (FNo 530) can be allocated to
the output which trips the circuit-breaker without creating further links. Then the
tripping command is sealed until the lock-out is reset via the binary reset input.
Naturally it has to be ensured in advance that the close coil at the circuit breaker — as
is usually done — is locked as long as a tripping command is maintained.
The output alarm "/2&.287" can also be applied to interlock certain closing
commands (externally or via CFC), e.g. by combining the output alarm with the binary
input "!&ORVH &PG %ON" (FNo ) or by connecting the inverted alarm with the
bay interlocking of the feeder.
The reset input "!/RFNRXW 5(6(7" (FNo ) resets the interlocking state. This input
is initiated by an external device which is protected against unauthorized or
unintentional operation. The lock-out state can also be reset by internal sources, e.g.
a function key, operation of the device or using DIGSI
For each case please make sure the corresponding logical combinations, security
measures, etc. are taken into account for the routing of the binary inputs and outputs
(Section 5.2) and are also considered for the setting of user-defined logic functions
(Section 5.3), if necessary.
While on feeder without automatic reclosure every trip command by a protection
function is final, it is desirable, when using automatic reclosure, to prevent the
operation detector of the circuit-breaker (intermediate contact on the breaker) from
sending an alarm if the trip of the breaker is not final (Figure 6-144).
For this purpose, the signal from the circuit-breaker is routed via a correspondingly
allocated output contact of the 7SA6 (output alarm "&% $ODUP 6XSS", FNo ). In
the idle state and when the device is turned off, this contact shall be closed. Therefore
an output contact with a normally closed contact (NC contact) has to be allocated.
Which contact is to be allocated is dependent on the device version. Refer to General
Diagrams in Appendix A, Subsection A.2.
$"
FNo
S Q LOCKOUT
R
Functions
®
4 on a PC.
6-277