Zone Sequencing / Fuse Saving Scheme - Siemens 7SC80 Manual

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Figure 2-98
2.14.5

Zone Sequencing / Fuse Saving Scheme

The zone sequencing / fuse saving scheme is not available for device versions 7SC8***-**A**-.
It is the task of the zone sequence coordination to harmonize the automatic reclosure function of this device
with that of another device that forms part of the same power system. It is a complementary function to the
automatic reclosure function and allows, for example, to perform group reclosing operations in radial systems.
In case of multiple reclosures, groups may also be in nested arrangement and further high-voltage fuses can
be overgraded or undergraded.
Zone sequencing works by blocking certain protection functions depending on the reclosing cycle. This is
implemented by the protection elements control (see margin heading "Controlling Protection Elements").
As a special feature, changing from one reclosing cycle to the next is possible without trip command only via
pickup/dropout of 50-1 or 50N-1.
The following figure shows an example of a group reclosure at feeder 3. It is assumed that reclosure is
performed twice.
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017
Control of protection elements for two-fold, successful automatic reclosure
Functions
2.14 Automatic Reclosing System 79
277