Settings - Siemens SIPROTEC 4 7SD80 Manual

Functions
2.6 Circuit Breaker Failure Protection 50BF
End Fault Protection
The end fault protection can be switched separately ON or OFF in address 3921 End Flt. elem.. An end
fault is a fault between the circuit breaker and the current transformer set of the feeder. The end fault protec-
tion presumes that the device is informed about the circuit-breaker position via breaker auxiliary contacts
connected to binary inputs.
If, during an end fault, the circuit breaker is tripped by a reverse element of the feeder protection or by the
busbar protection (the fault is a busbar fault as determined from the location of the current transformers), the
fault current will continue to flow, because the fault is fed from the remote end of the feeder circuit.
The time EndFault Delay (address 3922) is started when, during the time of pickup condition of the feeder
protection, the circuit-breaker auxiliary contacts indicate open poles and, at the same time, current flow is still
detected (address 3902). The trip command of the end fault protection is intended for the transmission of an
intertrip signal to the remote end circuit breaker.
Thus, the time delay must be set such that it can bridge out short transient apparent end fault conditions
which may occur during switching of the breaker.
2.6.3

Settings

The table indicates region-specific presettings. Column C (configuration) indicates the corresponding secon-
dary nominal current of the current transformer.
Addr. Parameter
3901 FCT 50BF Break.
3902 50BF PICKUP
3905 50BF-1 Delay 3p
3906 50BF-2 Delay
3907 T3-BkrDefective
3908 Trip BkrDefect.
3909 Chk BRK CONTACT
3912 50NBF PICKUP
3913 T2StartCriteria
3921 End Flt. elem.
3922 EndFault Delay
102
C Setting Options
ON
OFF
1A 0.05 .. 20.00 A
5A 0.25 .. 100.00 A
0.00 .. 30.00 sec
0.00 .. 30.00 sec
0.00 .. 30.00 sec
NO
with Local trip
with Bus trip
w/Local&Bustrip
NO
YES
1A 0.05 .. 20.00 A
5A 0.25 .. 100.00 A
With exp. of T1
Parallel withT1
ON
OFF
0.00 .. 30.00 sec
Default Setting Comments
ON 50BF Breaker Failure
Protection
0.10 A 50BF Pickup current
threshold
0.50 A
0.00 sec Delay after 3pole start for
local trip
0.15 sec Delay of 2nd element for
busbar trip
0.00 sec Delay for start with defec-
tive bkr.
NO Trip output selection with
defective bkr
YES Check Breaker contacts
0.10 A 50NBF Pickup neutral
current threshold
0.50 A
Parallel withT1 T2 Start Criteria
OFF End fault element
2.00 sec Trip delay of end fault
element
SIPROTEC 4, 7SD80, Manual
E50417-G1100-C474-A2, Edition 02.2018