Siemens SIPROTEC 7SD610 Manual page 309

External Initiation Conditions
If the breaker failure protection can also be started by external protection devices, the external start conditions
are checked. Depending on the device version and the setting of the breaker failure protection, 1-pole or 3-pole
trip are possible. The pole discrepancy check of the device or the actual breaker may lead to 3-pole tripping
after 1-pole tripping. Therefore check first how the parameters of the breaker failure protection are set. See also
Section 2.13.2, addresses 3901 onwards.
In order for the breaker failure protection to be started, a current must flow at least through the monitored phase
and the earth. This may be a secondary injected current.
After every start the indication „BF Start" (no. 1461) must appear in the spontaneous or fault indications.
If only 1-pole initiation is possible:
• Start by 1-pole trip command of the external protection L1:
Binary input functions „>BF Start L1" and, if necessary, „>BF release" (in spontaneous or fault indi-
cations). Trip command (depending on settings).
• Start by 1-pole trip command of the external protection L2:
Binary input functions „>BF Start L2" and, if necessary, „>BF release" (in spontaneous or fault indi-
cations). Trip command (depending on settings).
• Start by 1-pole trip command of the external protection L3:
Binary input functions „>BF Start L3" and, if necessary, „>BF release" (in spontaneous or fault indi-
cations). Trip command (dependent on settings).
• Start by 3-pole trip command of the external protection via all three binary inputs L1, L2 and L3:
Binary input functions „>BF Start L1", „>BF Start L2" and „>BF Start L3" and, if necessary,
„>BF release" (in spontaneous or fault indications). 3-pole trip command.
For 3-pole initiation:
• Start by 3-pole trip command of the external protection :
Binary input functions „>BF Start 3pole" and, if necessary, „>BF release" (in spontaneous or fault
indications). 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 „>BF Start w/o I" and, if necessary, „>BF release" (in spontaneous or fault
indications). Trip command (dependent on settings).
Busbar Tripping
The most important thing is the check of the correct distribution of the trip commands to the adjacent circuit
breakers in case of breaker failure.
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 surrounding circuit breakers must be
checked. Here check 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.
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
Mounting and Commissioning
3.3 Commissioning
309