Siemens siprotec 7SA6 User Manual page 267

7SA6 Manual
C53000-G1176-C133-1
function. This "Weak Infeed Function" (echo function) is referred to in Sub-section
6.4.1.11. It is activated when a signal is received from the opposite line end — in the
case of three terminal lines from at least one of the opposite line ends — without the
device having detected a fault.
The circuit breaker can also be tripped at the line end that has only weak or no infeed.
This "Weak-Infeed Tripping" is referred to in Section 6.7.
Dis Telep. off
FNr 4003
>Dis.Telep. Blk
FNr 4005
>Dis. RecFail
Transient Blocking
(Section 6.4.1.10)
TRIP Command
Dis. forward L1
Dis. forward L2
Dis. forward. L3
Dis. forward

„1"
FNr 4006
>DisTel Rec.Ch1
FNr 4010
>DisTel Rec.Ch2
FNr 4007
>Dis.T.RecCh1L1
FNr 4008
>Dis.T.RecCh1L2
FNr 4009
>Dis.T.RecCh1L3
Figure 6-50 Logic diagram of the directional comparison pick-up scheme (one line end)
≥1
&
à 
Send Prolong
0 T
&
≥1
0 T
&
≥1
0 T
&
≥1
0 T
&
≥1
Ã
Line Config.
Two terminals
Three terminals
Two terminals
Three terminals
≥1
≥1
FNr 4052
Dis.Telep.OFF
FNr 4055
Dis.T.Carr.Fail
FNr 4057
&
Dis.T.SEND L1
FNr 4058
&
Dis.T.SEND L2
FNr 4059
&
Dis.T.SEND L3
FNr 4056
&
Dis.T.SEND
Echo function
&
≥1
Section 6.4.1.11
&
≥1
Z4 instantaneous trip L1
&
≥1
Z4 instantaneous trip L2
&
≥1
&
Z4 instantaneous trip L3
Functions
6-85