Siemens SIPROTEC 7SJ62 Manual page 109

During a busbar fault, the device that detects faults in reverse (busbar) direction using the directional relay
element 67-1 will block one of the non-directional overcurrent elements (50-1, 50-TOC) of devices at the oppo-
site end of the same feeder. In addition, a "Reverse" message is generated and transmitted via the auxiliary
voltage loop to the relay located at the opposite end of the line.
Figure 2-31
The directional overcurrent element providing normal time grading operates as selective backup protection.
The following figure shows the logic diagram for the generation of fault direction signals.
Figure 2-32
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
Reverse interlocking using directional elements
Logic diagram for the generation of fault direction signals
2.3 Directional Overcurrent Protection 67, 67N
Functions
109