Checking The Instrument Transformer Connections Of One Line End - Siemens SIPROTEC 4 7SD80 Manual

External Initiation Conditions
If the breaker failure protection can be started by external protection devices, the external start conditions
must be checked. Therefore, check first how the parameters of the breaker failure protection are set. See also
Section 2.6.2 Setting
In order for the breaker failure protection to be started, a current must flow at least via the monitored phase
and ground. This may be a secondary injected current.
After every start, the message
tions.
For three-pole starting:
•
Three-pole starting by trip command of the external protection:
Binary input functions
messages). Trip command (dependent on settings).
Switch off test current.
If start is possible without current flow:
•
Starting by trip command of the external protection without current flow:
Binary input functions
fault messages). Trip command (dependent on settings).
Busbar Tripping
For testing the distribution of the trip commands in the substation in the case of breaker failures it is impor-
tant to check that the trip commands to the adjacent circuit breakers are correct.
The adjacent circuit breakers are those of all feeders which must be tripped in order to ensure interruption of
the fault current should the local breaker fail. These 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 largely
depends on the system topology.
In particular with multiple busbars, the trip distribution logic for the adjacent circuit breakers must be checked.
Here it should be checked for every busbar section that all circuit breakers which are connected to the same
busbar section as the feeder circuit breaker under observation are tripped, and no other breakers.
Auslösung des Gegenendes
Wenn das Auslösekommando des Leistungsschalter-Versagerschutzes auch den Leistungsschalter am Gege-
nende des betrachteten Abzweigs auslösen soll, muss auch der Übertragungskanal für diese Fernauslösung
überprüft werden. Dies geschieht zweckmäßig zusammen mit der Übertragung weiterer Signale gemäß des
Abschnitts "Prüfung der Signalübertragung mit ..." weiter unten.
Termination
All temporary measures taken for testing must be undone, e.g. especially switching states, interrupted trip
commands, changes to setting values or individually switched off protection functions.
3.3.8

Checking the Instrument Transformer Connections of One Line End

If secondary test equipment is connected to the device, it is to be removed or, if applying, test switches should
be in normal operation position.
NOTE
i
i
It must be taken into consideration that tripping can occur even at the opposite end of the protected object
if connections were made wrong.
Before energizing the object to be protected at one end, short-circuit protection must be ensured at least at
the feeding ends. If a separate backup protection (e.g. time overcurrent protection) is available, it has to be
put into operation and switched to alert first.
SIPROTEC 4, 7SD80, Manual
E50417-G1100-C474-A2, Edition 02.2018
Notes, addresses 3901 onwards.
50BF Start (FNo 1461) must appear in the spontaneous or fault annuncia-
>50BF Start 3p and, if necessary, >50BF release (in or spontaneous or fault
>50BF STARTw/oI and, if necessary, >50BF release (in or spontaneous or
Mounting and Commissioning
3.3 Commissioning
239