Functions
6-257
7SA6 Manual
C53000-G1176-C156-2
Figure 6-131 Two-stage breaker failure protection with phase segregated initiation — one
phase
Circuit Breaker not
Operational
There may be cases when it is immediately apparent that the circuit breaker associat-
ed with a feeder protection relay cannot clear a fault, e.g. when the tripping voltage or
the tripping energy is not available.
In such a case it is not necessary to wait for the response of the feeder circuit breaker.
If provision has been made for the detection of such a condition (e.g. control voltage
monitor or air pressure monitor), the monitor alarm signal can be fed to the binary input
“
>CB faulty
” of the 7SA6. On occurrence of this alarm and a trip command by the
feeder protection, a separate timer
T3-BkrDefective
, which is normally set to 0, is
started (Figure 6-132). Thus, the adjacent circuit breakers (bus-bar) are tripped imme-
diately in case the feeder circuit breaker is not operational.
Figure 6-132 Circuit breaker not operational
Transfer Trip to the
Remote End Circuit
Breaker
The 7SA6 has the facility to give an additional intertrip signal to the circuit breaker at
the remote line end in the event that the local feeder circuit breaker fails. For this, a
suitable protection signal transmission link is required (e.g. via communication cable,
power line carrier transmission, radio transmission, or optical fibre transmission).
To realise this intertrip, the desired command — usually the trip command which is in-
tended to trip the adjacent breakers — is assigned to a binary output of the device.
The contact of this output triggers the transmission device.
BF T1-TRIP L123
BF T2-TRIP (bus)
(Trip
bus-bar)
Start only L1
Start only L2
Start only L3
Start L123
> 1
T 0
T 0
3904
T1-1Pole
3905
T1-3Pole
T 0
3906
T2
> 1
Yes
No
3903
1p-RETRIP (T1)
> 1
&
BF T1-TRIP 1pL1
Start only L1
(accordingly for
other phases)
(Trip repetition
feeder breaker)
FNo 1472
FNo 1476
FNo 1494
T
0
&
(all initiation
conditions
Fig 6-125/6-128)
3907
T3-BkrDefective
>CB faulty
BF TRIP CBdefec
BF Start
FNo 378
FNo 1493
FNo 1461
Summary of Contents for siprotec 7SA6
Page 2: ...Siemens Aktiengesellschaft Book No C53000 G1176 C156 2 ...
Page 18: ...xviii 7SA6 Manual C53000 G1176 C156 2 ...
Page 32: ...Introduction 1 14 7SA6 Manual C53000 G1176 C156 2 ...
Page 82: ...Hardware and Connections 2 50 7SA6 Manual C53000 G1176 C156 2 ...
Page 119: ...SIPROTEC 4 Devices 4 25 7SA6 Manual C53000 G1176 C156 2 Figure 4 20 CFC Logic example ...
Page 190: ...Configuration 5 62 7SA6 Manual C53000 G1176 C156 2 ...
Page 652: ...Installation and Commissioning 8 78 7SA6 Manual C53000 G1176 C156 2 ...
Page 724: ...Technical Data 10 56 7SA6 Manual C53000 G1176 C156 ...
Page 800: ...Appendix A 76 7SA6 Manual C53000 G1176 C156 2 ...
Page 866: ...Appendix B 66 7SA6 Manual C53000 G1176 C156 2 ...