
Functions
2.11 Automatic Reclosing System 79
SIPROTEC, 7SJ61, Manual
C53000-G1140-C210-1, Release date 02.2008
173
For the busbar fault F2, the 50-2 element at the bus would have cleared the fault in 0.4 seconds. Zone sequenc-
ing enables the user to set a relatively short time period for the 50-2 elements. The 50-2 element is only used
as backup protection. If zone sequencing is not applied, the 50-1 element is to be used only with its relatively
long time period (0.9 s).
Figure 2-59
Zone sequencing with a fault occurring at Tap Line #5 and the busbar
2.11.6
Setting Notes
General Settings
The internal automatic reclosure system will only be effective and accessible if address
171
79 Auto Recl.
is set
Enabled
during configuration. If not required, this function is set to
Disabled
. The function can be
turned
ON
or
OFF
under address
7101
FCT 79
.
If no automatic reclosures are performed on the feeder for which the 7SJ61 is used (e.g. cables, transformers,
motors, etc.), the automatic reclosure function is disabled by configuration. The automatic reclosure function is
then completely disabled, i.e. the automatic reclosure function is not processed in the 7SJ61. No messages
exist for this purpose and binary inputs for the automatic reclosure function are ignored. All parameters of block
71 are inaccessible and of no significance.
Blocking Duration for Manual-CLOSE Detection
Parameter
7103
BLOCK MC Dur.
defines the reaction of the automatic reclosure function when a manual
closing signal is detected. The parameter can be set to specify how long the auto reclose function will be
blocked dynamically in case of an external manual close-command being detected via binary input (356
„>Manual Close“
). If the setting is 0, the automatic reclosure system will not respond to a manual close-
signal.
Restraint Time and Dynamic Blocking
The blocking time
TIME RESTRAINT
(address
7105
) defines the time that must elapse, after a successful re-
closing attempt, before the automatic reclosing function is reset. If a protective function configured for initiation
of the auto-reclosure function provokes a new trip before this time elapses, the next reclosing cycle is started
in case of multiple reclosures. If no further reclosure is allowed, the last reclosure will be classed as unsuccess-
ful.
In general, a few seconds are sufficient. In areas with frequent thunderstorms or storms, a shorter blocking time
may be necessary to avoid feeder lockout due to sequential lightning strikes or flashovers.