Siemens Siprotec 7VK61 Manual page 159

applied, only the final trip of the protection function should activate reclosing lockout. Please bear in mind that
the message „Definitive TRIP" (no. 536) applies only for 500 ms. Then combine the output indication
„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.
In the most simple case, the output indication „LOCKOUT" (No. 530) can be allocated to the output which trips
the circuit breaker without creating further links. Then the trip command is maintained until the interlock is reset
via the 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 trip command is maintained.
The output indication „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 make sure that the corresponding logical combinations, security measures, etc. are taken
into account for the routing of the binary inputs and outputs and are also considered for the setting of user-
defined logic functions, if necessary. See also the SIPROTEC 4 System Description.
Breaker Tripping Alarm Suppression
While on feeders 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 (transient contact on
the breaker) from sending an alarm if the trip of the breaker is not final (Figure 2-64).
For this purpose, the signal from the circuit breaker is routed via a correspondingly allocated output contact of
the 7VK61 (output indication „CB Alarm Supp", no. 563). In the idle state and when the device is turned off,
this contact is closed. Therefore an output contact with a normally closed contact (NC contact) has to be allo-
cated. Which contact is to be allocated depends on the device version. Refer to the general views in the Ap-
pendix.
Prior to the command, with the internal automatic reclosure in the ready state, the contact opens so that no
signal from the circuit breaker is forwarded. This is only the case if the device is equipped with internal auto-
matic reclosure and if the latter was taken into consideration when configuring the protective functions (address
133).
Also when closing the breaker via the binary input „>Manual Close" (No 356) or via the integrated automatic
reclosure the contact is interrupted so that the breaker alarm is inhibited.
Further optional closing commands which are not sent via the device cannot be taken into consideration.
Closing commands for control can be linked to the alarm suppression via the user-defined logic functions
(CFC).
Figure 2-64
SIPROTEC, 7VK61, Manual
C53000-G1176-C159-3, Release date 05.2009
Breaker tripping alarm suppression
Functions
2.8 Function Control
159