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Figure 2-37
shows the generation of the internal signal "52 closed" (see
pole is closed.
Using binary input 1424
has elapsed, the breaker failure protection TRIP command 1494
[lo-svs-signal-hiko-20101108, 1, en_US]
Figure 2-37
If an internal protection function or an external protection device trips without current flow, the breaker
failure protection is initiated by the internal input "Start internal w/o I", if the trip signal comes from the
internal voltage protection or frequency protection, or by the external input
the start signal is maintained until the circuit breaker is signaled to be open by the auxiliary contact criterion.
Initiation can be blocked via the binary input
[lo-svs-phasengem-anwurf-20101108, 1, en_US]
Figure 2-38
Time Delays
When the initiate conditions are fulfilled, the associated timers are started. The circuit-breaker pole(s) must
open before the associated time has elapsed.
Time delays can be set for 3-pole initiation and for two-element protection.
With single-element breaker failure protection, the trip command is relayed to the adjacent circuit breakers
which interrupt the fault current if the local feeder breaker fails (see
cent circuit breakers are those located at the busbar or busbar section to which the feeder under consideration
SIPROTEC 4, 7SD80, Manual
E50417-G1100-C474-A2, Edition 02.2018
>50BFSTRTonlyT2 , the trip time delay 3906 50BF-2 Delay can be started. After it
Generation of the signal "CB aux closed"
Circuit-breaker failure protection with common phase initiation
50BF BusTrip is generated.
>BLOCK 50BF (e.g. during test of the feeder protection relay).
Figure 2-34
2.6 Circuit Breaker Failure Protection 50BF
Figure 2-38
left) if at least one breaker
>50BF STARTw/oI . In this case
and
Figure
2-35). The adja-
Functions
97
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