Functions
2.11 Automatic Reclosing System 79
SIPROTEC, 7SJ61, Manual
C53000-G1140-C210-1, Release date 02.2008
162
2.11 Automatic Reclosing System 79
From experience, about 85 % of insulation faults associated with overhead lines are arc short circuits which
are temporary in nature and disappear when protection takes effect. This means that the line can be connected
again. The reconnection is accomplished after a dead time via the automatic reclosing system.
If the fault still exists after automatic reclosure (arc has not disappeared, there is a metallic fault), then the pro-
tective elements will re-trip the circuit breaker. In some systems several reclosing attempts are performed.
Applications
• The automatic reclosure system integrated in the 7SJ61 can also be controlled by an external protection
device (e.g. backup protection). For this application, an output contact from the tripping relay must be wired
to a binary input of the 7SJ61 relay.
• It is also possible to allow the relay 7SJ61 to work in conjunction with an external reclosing device.
• Since the automatic reclosing function is not applied when the 7SJ61 is used to protect generators, motors,
transformers, cables and reactors etc., it should be disabled for this application.
2.11.1 Program Execution
The 7SJ61 is equipped with an integrated three-pole, single-shot and multi-shot automatic reclosure (AR).
Figure 2-56 shows an example of a timing diagram for a successful second reclosure.
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