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Functions
2.25 Function Control and Circuit Breaker Test
Breaker Tripping Alarm Suppression
On feeders without automatic reclosure, every trip command by a protection function is final. But when using
automatic reclosure, it is desired that the operation detector of the circuit breaker (fleeting contact at the break-
er) should only generate an alarm if the trip of the breaker is final (Figure 2-226).
To accomplish this, the signal from the circuit breaker can be routed via an output contact of the 7SD5 (output
alarm „CB Alarm Supp", No. 563) that is configured accordingly. In the idle state and when the device is
turned off, this contact is closed. This requires that a normally closed contact is allocated. Which contact is to
be allocated depends on the device version. See also the general views in the Appendix.
Prior to a trip command with the internal automatic reclosure in the ready state, the contact opens so that the
tripping of the circuit breaker is not passed on. This is only the case if the device is equipped with internal au-
tomatic reclosure and if the latter was taken into consideration when configuring the protection functions (ad-
dress 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 are not taken into consideration. Closing
commands for control can be linked to the alarm suppression via the user-defined logic functions (CFC).
Figure 2-226
If the device issues a final trip command, the contact remains closed. This is the case, during the reclaim time
of the automatic reclosure cycle, when the automatic reclosure is blocked or switched off or, due to other
reasons is not ready for automatic reclosure (e.g. tripping only occurred after the action time expired).
Figure 2-227 shows time diagrams for manual trip and close as well as for short-circuit tripping with a single,
failed automatic reclosure cycle.
456
Breaker tripping alarm suppression
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
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