Siemens siprotec 7SA522, User Manual

Page: 231 / 628

Functions
6-83
7SA522 Manual
C53000-G1176-C119-2
This “Weak Infeed Function” (echo function) is referred to in Sub-section 6.4.1.7. 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.
Figure 6-48 Logic diagram of the permissive overreach transfer trip (POTT) scheme (one line
end)
Two terminals
Dis Telep. off
≥
1
Dis Z1B L1
&
Dis Z1B L2
&
Dis Z1B L3
&
Dis Z1B
&
Dis. forward
6HQG3URORQJ
T 0
&
&
&
&
>Dis.T.RecCh1L1
>Dis.T.RecCh1
>Dis.T.RecCh1L2
&
&
&
≥
1
≥
1
≥
1
Dis Enable Z1B/T1B L1
>DisTel Rec.Ch1
>DisTel Rec.Ch2
Three terminals
Two terminals
Three terminals
„1“
/LQH&RQILJ
≥
1
&
Trip command
&
&
&
&
T 0
T 0
T 0
≥
1
≥
1
≥
1
≥
1
≥
1
≥
1
Dis.Telep.OFF
Dis.T.SEND L1
Dis.T.SEND L2
Dis.T.SEND L3
Dis.T.SEND
&
&
Transient blocking
(section 6.4.1.6)
Echo function
section 6.4.1.7
Weak infeed trip
section 6.7
4052
4057
4058
4059
4056
4003 >Dis.Telep. Blk
Dis Enable Z1B/T1B L2
Dis Enable Z1B/T1B L3