Siemens SIPROTEC 4 7SD80 User Manual

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.
Settings
The table indicates region-specific presettings. Column C (configuration) indicates the corresponding secon-
dary nominal current of the current transformer.
Addr. Parameter C Setting Options Default Setting Comments
3901 FCT 50BF Break. ON
OFF
ON 50BF Breaker Failure
Protection
3902 50BF PICKUP 1A 0.05 .. 20.00 A 0.10 A 50BF Pickup current
threshold
5A 0.25 .. 100.00 A 0.50 A
3905 50BF-1 Delay 3p 0.00 .. 30.00 sec 0.00 sec Delay after 3pole start for
local trip
3906 50BF-2 Delay 0.00 .. 30.00 sec 0.15 sec Delay of 2nd element for
busbar trip
3907 T3-BkrDefective 0.00 .. 30.00 sec 0.00 sec Delay for start with defec-
tive bkr.
3908 Trip BkrDefect. NO
with Local trip
with Bus trip
w/Local&Bustrip
NO Trip output selection with
defective bkr
3909 Chk BRK CONTACT NO
YES
YES Check Breaker contacts
3912 50NBF PICKUP 1A 0.05 .. 20.00 A 0.10 A 50NBF Pickup neutral
current threshold
5A 0.25 .. 100.00 A 0.50 A
3913 T2StartCriteria With exp. of T1
Parallel withT1
Parallel withT1 T2 Start Criteria
3921 End Flt. elem. ON
OFF
OFF End fault element
3922 EndFault Delay 0.00 .. 30.00 sec 2.00 sec Trip delay of end fault
element
2.6.3
Functions
2.6 Circuit Breaker Failure Protection 50BF
102 SIPROTEC 4, 7SD80, Manual
E50417-G1100-C474-A2, Edition 02.2018

Siemens SIPROTEC 4 7SD80 Specifications

General

Brand	Siemens
Model	SIPROTEC 4 7SD80
Category	Power distribution unit
Language	English