Siemens siprotec 7SA522 - Page 179

2.8 Teleprotection for earth fault overcurrent protection (optional)
179
7SA522 Manual
C53000-G1176-C155-3
Figure 2-76 Logic diagram of the directional comparison scheme (one line end)
Figure 2-77 and 2-78 shows the logic diagram of the directional comparison scheme
for one line end with protection interface.
For earth fault protection, only directional comparison pickup is offered for transmis-
sion via protection interface. The directional comparison pickup scheme is only effec-
tive if the parameter  7HOHSURW() was set to 6,*1$/Y3URW,QW in all
devices of the setup. In the event of a fault, the indication ´3DUGLIIHUHQWµ is
output.