Setting Notes - Siemens 7SC80 Manual

Functions
2.14 Automatic Reclosing System 79
With fault F1 on feeder 5, protection devices in the infeed and on feeder 3 pick up. The time delay of the 50-2
element at protecting feeder 3 is set in such a way that the feeder 3 circuit breaker will clear the fault before
the fuse at feeder 5 is damaged. If the fault is cleared, all functions are reset after the restraint time has
expired and the fault is terminated. The fuse has therefore also been protected.
If the fault continues to exist, a second reclosing cycle is performed in the same way.
High speed element 50-2 is now blocked at relay protecting Feeder 3. If the fault still remains, only the 50-1
element continues to be active in Feeder 3 which, however, overgrades the fuse with a time delay of 0.4 s.
After the fuse operated to clear the fault, the series-connected devices drop out. If the fuse fails to clear the
fault, then the 50-1 element protecting Feeder 3 will operate as backup protection.
The 50-2 element at the busbar relay is set with a delay of 0.4 seconds, since it supposed to trip the 50-2
elements and the fuses as well. For the second reclosing, the 50-2 element also has to be blocked to give pref-
erence to the feeder relay (50-1 element with 0.4 s). For this purpose, the device has to "know" that two
reclosing attempts have already been performed.
In this device, zone sequence coordination must be switched on: When pickup of 50-1 or 50N-1 drops out,
zone sequence coordination provokes that the reclosing attempts are counted as well. If the fault still persists
after the second reclosure, the 50-1 element, which is set to 0.9 seconds, would serve as backup protection.
For the busbar fault F2, the 50-2 element at the bus would have cleared the fault in 0.4 seconds. Zone
sequencing enables the user to set a relatively short time period for the 50-2 elements. The 50-1 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).
[ablaufkoordinierung-fehler-am-abgang-5-ss-260602-kn, 1, en_US]
Figure 2-99
2.14.6

Setting Notes

General Settings
The internal automatic reclosure function 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 reclosing is performed on the feeder for which the 7SC80 is used (e.g. cables, transformers,
motors, etc.), the automatic reclosing function is disabled. The automatic reclosing function then has abso-
lutely no effect, that is there will be no associated indications, and binary inputs for the automatic reclosing
function are ignored. All parameters of block 71 are inaccessible and not relevant.
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 reclosure 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 function will not respond to a Manual close
signal.
278
Zone sequencing with a fault occurring at Tap Line 5 and at the busbar
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017