Siemens 6MD85, Manual

Page: 1065 / 1256

Start by Trip Command from the External Protection
²
Check the static and - in case of 2-channel operation - also the dynamic supervision of the binary input
signals. For this purpose, induce pickup of the supervision and check the supervision indications and the
ready signal in the event log buffer.
Start by Trip Command from the External Protection without Current Flow
²
If start is possible without current flow: (see Start by trip command of the external protection).
Repetition of the Local Tripping (T1)
²
Make sure that the trip repeat signal controls a 2nd circuit (2nd coil) for switching off the circuit breaker.
Backup Tripping in the Case of a Circuit-Breaker Failure (T2)
For tests in the station, it is important to check that the distribution of trip commands to the adjacent circuit
breakers in the case of a circuit-breaker failure is correct. The adjacent circuit breakers are all circuit breakers,
which must be tripped in order to ensure interruption of the short-circuit current if the feeder circuit breaker
fails. They are therefore the circuit breakers of all feeders which feed the busbar or busbar section to which
the feeder with the fault is connected.
A general detailed test guide cannot be specified because the layout of the adjacent circuit breakers depends
largely on the system topology.
²
With multiple busbars, the trip distribution logic for the adjacent circuit breakers must be checked.
The test has to check for every busbar section that, in case of a failure of the feeder circuit breaker under
observation, only those circuit breakers which are connected to the same busbar section are tripped.
Backup Tripping on Circuit-Breaker Failure (T2), Tripping of the Opposite End
If the trip command of the circuit-breaker failure protection must also trip the circuit breaker at the opposite
end of the tested feeder, the communication channel for this remote trip has to be tested as well.
Termination
²
All temporary measures taken for testing must be undone, such as special switch positions, interrupted
trip commands, changes to setting values, or individually switched off protection functions.
Functional Tests
10.3 Primary and Secondary Tests of the Circuit-Breaker Failure Protection
SIPROTEC 5, High-Voltage Bay Controller, Manual 1065
C53000-G5040-C015-9, Edition 11.2017