Siemens SIPROTEC 4 7SJ61 Manual page 154

Functions
2.11 Automatic Reclosing System 79
the settings for the starting cycle apply. These settings always take effect when the automatic reclosure func-
tion assumes normal state.
The settings are released for each following cycle when issuing the close command and starting the blocking
time. Following a successful reclosure (blocking time expired) or after returning from the blocking, the auto-
matic reclosure function goes into normal state. Control of the protection is again assumed by the parameters
for the starting cycle.
The following figure illustrates the control of the protection elements 50-2 and 50N-2.
[schutzstufensteuerung-bei-zweimaliger-erfolgreicher-awe-260602-kn, 1, en_US]
Figure 2-60
Example
Before the first reclosing, faults are to be eliminated quickly applying elements 50-2 or 50N-2. Fast fault termi-
nation thus has priority over selectivity aspects as the reclosing action aims at maintaining normal system
operation. If the fault prevails, a second tripping is to take place instantaneously and subsequently, a second
reclosing.
After the second reclosing, however, elements 50-2 or 50N-2 are to be blocked so the fault can be eliminated
by applying elements 50-1 or 50N-1 according to the grading coordination chart of the system giving priority
to selectivity concerns.
154
Control of protection elements for two-fold, successful automatic reclosure
SIPROTEC 4, 7SJ61, Manual
C53000-G1140-C210-6, Edition 05.2016