Siemens SIPROTEC 7SS523 V3.2 Manual page 153

5.4.3 Setting Notes
T-CB open
End Fault Prot
T-BF-1P
T-BF-mP
5.4.4 Settings for the Central Unit
Addr. Setting Title
118 I> BF
119 I> BF-EF
120 T-BF-1P
121 T-BF-mP
125 T-TRIP repeat
126 T-CB open
129 End Fault Prot
The parameter T-CB open (XX23/CU) is used to delay processing of the circuit
breaker OPEN status for special treatment of the coupler currents and for the end fault
protection.
If the bay is configured as a feeder, the parameter End Fault Prot (XX29/CU) is
used to activate and deactivate the end fault protection. For coupler bays the setting
of this parameter is not relevant.
The parameter T-BF-1P (XX20/CU) is used to delay for 1-pole earth faults the TRIP
command and the transfer trip signal issued by the breaker failure protection.
This delay time must be set higher than the sum of delay times set with the parameters
T-TRIP repeat (XX25/CU) aund Tmin TRIP (6106/CU) for 2-stage CBF.
Siemens recommends to set this parameter to twice the circuit breaker trip time.
The parameter T-BF-mP (XX21/CU) is used to delay for multipole faults the TRIP
command and the transfer trip signal issued by the breaker failure protection.
This delay time must be set higher than the sum of delay times set with the parameters
T-TRIP repeat (XX25/CU) aund Tmin TRIP (6106/CU) for 2-stage CBF.
Siemens recommends to set this parameter to twice the circuit breaker trip time.
Setting Options
0.10 .. 2.00 I / In
0.05 .. 2.00 I / In
0.05 .. 10.00 s
0.05 .. 10.00 s
0.00 .. 10.00 s
0.00 .. 10.00 s
ON
OFF
Default Setting
0.50 I / In Current threshold for BF
0.25 I / In Current threshold for BF - EF
0.25 s Time delay for BF with 1-pole fault
0.25 s Time delay for BF with multi-pole
faults
0.12 s Time delay for TRIP repeat
0.00 s Time delay for CB open
OFF End fault protection
7SS52 V4 Manual
C53000-G1176-C182-1
End Fault Protection
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