Siemens SIPROTEC 7SD80 Manual page 196

Functions
2.16 Function Control
Reclosure Interlocking
After the circuit breaker has been tripped by a protection function, the reclosing must often be blocked until the
cause for tripping of the protection function has been found. 7SD80 enables this via the integrated reclosure
interlocking.
The interlocking state („LOCKOUT") will be realized by an RS flipflop which is protected against auxiliary
voltage failure (see Figure 2-79). The RS flipflop is set via binary input „>Lockout SET" (no. 385). With the
output indication „LOCKOUT" (no. 530), if interconnected correspondingly, reclosing of the circuit breaker (e.g.
for automatic reclosing, manual close signal, closing via control) can be blocked. The interlocking should only
be reset manually via binary input „>Lockout RESET" (no. 386) when the cause of the fault has been deter-
mined.
Figure 2-79 Reclosure interlocking
The conditions for reclosure interlocking and the control commands to be blocked can be parameterized. The
correspondingly routed binary inputs and outputs are wired externally or 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 „Relay TRIP" (No. 511) with the binary input „>Lockout SET". If automatic reclosure is applied,
only the final trip of the protection function should activate reclosing lock-out. Please bear in mind that the
message „Definitive TRIP" (No. 536) applies only for 500°ms. Then combine the output alarm
„Definitive TRIP" (No. 536) with the interlocking input „>Lockout SET", so that the interlocking function
is not established when an automatic reclosure is still expected to come.
The output alarm „LOCKOUT" can also be applied to interlock certain closing commands (externally or via
CFC), e.g. by combining the output alarm with the binary input „>Blk Man. Close" (No. 357) or by connect-
ing the inverted alarm with the bay interlocking of the feeder.
The output alarm „LOCKOUT" can also be applied to interlock certain closing commands (externally or via
CFC), e.g. by combining the output alarm with the binary input „>Blk Man. Close" (No. 357) or by connect-
ing the inverted alarm with the bay interlocking of the feeder.
The reset input „>Lockout RESET" (no. 386) resets the interlocking state. This input is initiated by an external
device which is protected against unauthorized or unintentional 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 on a PC.
For each case please ensure that the corresponding logic operations, security measures, etc. are taken into
account when routing the binary inputs and outputs and may have to be considered when creating the user-
defined logic functions. See also the SIPROTEC 4 System Description.
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SIPROTEC, 7SD80, Manual
E50417-G1140-C474-A1, Release date 09.2011