Siemens 7SK80 Manual page 291

Siprotec motor protection
Hide thumbs Also See for 7SK80:
Table of Contents

Advertisement

Figure 2-105
Standard Interlocking (default)
The standard interlockings contain the following fixed programmed tests for each switching device, which can
be individually enabled or disabled using parameters:
• Device Status Check (set = actual): The switching command is rejected, and an error indication is displayed
if the circuit breaker is already in the set position. (If this check is enabled, then it works whether interlocking,
e.g. zone controlled, is activated or deactivated.) This condition is checked in both interlocked and non-in-
terlocked status modes.
• System Interlocking: To check the power system interlocking, a local command is transmitted to the central
unit with Switching Authority = LOCAL. A switching device that is subject to system interlocking cannot be
switched by DIGSI.
• Zone control: User-specific logic links created with CFC are interrogated and considered during interlocked
switching.
• Blocking by Protection: Switch-ON commands are rejected with interlocked switches, as soon as one of the
protection functions of the unit has opened a fault case. The OPEN-command, by contrast, can always be
executed. Please be aware, activation of thermal overload protection elements or sensitive ground fault de-
tection can create and maintain a fault condition status, and can therefore block CLOSE commands. If the
interlocking is removed, consider that, on the other hand, the restart inhibit for motors will not automatically
reject a CLOSE command to the motor. Therefore, a restart inhibit must be provided by other means, e.g.
by a bay interlocking using CFC.
• Double Operation Block: Parallel switching operations are interlocked against one another; while one
command is processed, a second cannot be carried out.
• Switching Authority LOCAL: A switch command from local control (command with source LOCAL) is only
allowed if local control is enabled at the device (by configuration).
• Switching Authority DIGSI: Switching commands that are issued locally or remotely via DIGSI (command
with source DIGSI) are only allowed if remote control is enabled at the device (by configuration). If a DIGSI
computer logs on to the device, it leaves a Virtual Device Number (VD). Only commands with this VD (when
Switching Authority = REMOTE) will be accepted by the device. Remote switching commands will be reject-
ed.
• Switching authority REMOTE: A remote switch command (command with source REMOTE) is only allowed
if remote control is enabled at the device (by configuration).
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
Example of an operational annunciation for switching circuit breaker 52 (Q0)
Functions
2.21 Command Processing
291

Advertisement

Table of Contents
loading

Table of Contents