Siemens SIPROTEC 7SA522 Manual page 341

Reclosure Inter-
locking
7SA522 Manual
C53000-G1176-C155-3
When tripping the circuit breaker by a protection function the manual reclosure must
often be blocked until the cause for the protection function operation is found. 7SA522
enables this via the integrated reclose interlocking.
The interlocking state ("LOCKOUT") will be realized by a RS flipflop which is protected
against auxiliary voltage failure (see Figure 2-154). The RS flipflop is set via binary
input ´!/RFNRXW 6(7µ (FNo. 385). With the output alarm ´/2&.287µ (FNo. 530), if
interconnected correspondingly, a reclosure of the circuit-breaker (e.g. for automatic
reclosure, manual close signal, synchronization, closing via control) can be blocked.
Only once the cause for the protection operation is known, should the interlocking be
reset by a manual reset via binary input ´!/RFNRXW 5(6(7µ (FNo. 386).
Figure 2-154 Reclosure interlocking
Conditions which cause reclosure interlocking and control commands which have to
be interlocked 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 has to cause a closing lock-out,
then combine the tripping command ´5HOD\ 75,3µ (FNo. 511) with the binary input
´!/RFNRXW 6(7µ. If, however, automatic reclosure is applied, only the final trip of the
protection function should activate reclosing lock-out. Please bear in mind that the
alarm ´'HILQLWLYH 75,3µ (FNo. 536) is only present for 500 ms. Combine the
output alarm ´'HILQLWLYH 75,3µ (FNo. 536) with the interlocking input
´!/RFNRXW 6(7µ, so that the interlocking function is not established when an auto-
matic reclosure is still expected to come.
With the output alarm ´/2&.287µ (FNo. 530) it is possible in the most simple case to
allocate to the output which trips the circuit-breaker without creating further links. Then
the tripping command is maintained until the interlock 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 blocked as long as a tripping command is maintained.
The output alarm ´/2&.287µ can also be applied to interlock certain closing com-
mands (externally or via CFC), e.g. by combining the output alarm with the binary input
´!&ORVH &PG %ONµ (FNo. 357) or by connecting the inverted alarm with the bay
interlocking of the branch.
The reset input ´!/RFNRXW 5(6(7µ (FNo. 386) resets the interlocking state. This
input is initiated by an external device which is protected against unauthorized or un-
intentional operation. The interlocking state can also be controlled by internal sources
using CFC, 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 ) and are also considered for the setting of user-defined logic functions, if nec-
essary. See also SIPROTEC
2.20 Function control and circuit breaker testing
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4 System Description, Order no.. E50417-H1176-C151.
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on a PC.
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