
Functions
2.18 Breaker Control
SIPROTEC, 7SJ61, Manual
C53000-G1140-C210-1, Release date 02.2008
254
Zone Controlled / Field Interlocking
Zone controlled / Field interlockings (e.g. via CFC) includes the verification that predetermined switchgear po-
sition conditions are satisfied to prevent switching errors (e.g. disconnector vs. ground switch, ground switch
only if no voltage applied) as well as verification of the state of other mechanical interlocking in the switchgear
bay (e.g. High Voltage compartment doors open against CB closing).
Interlocking conditions can be programmed separately for device control CLOSE and/or OPEN.
The enable information with the data "switching device is interlocked (OFF/NV/FLT) or enabled (ON)" can be
set up,
• directly, using a single point or double point indication, key-switch, or internal indication (marking), or
• by means of a control logic via CFC.
When a switching command is initiated, the actual status is scanned cyclically. The assignment is done via "Re-
lease object CLOSE/OPEN command".
System Interlocking
Substation Controller (System interlocking) involves switchgear conditions of other bays evaluated by a central
control system.
Double Activation Blockage
Parallel switching operations are interlocked. As soon as the command has arrived all command objects
subject to the interlocking are checked to know whether a command is being processed. While the command
is being executed, interlocking is enabled for other commands.
Blocking by Protection
Protection functions then block switching operations. Protective elements are configured, separately for each
switching component, to block specific switching commands sent in CLOSE and TRIP direction.
When enabled, "Block CLOSE commands" blocks CLOSE commands, whereas "Block TRIP commands"
blocks TRIP signals. Switching operations in progress will immediately be aborted by the pickup of a protective
element.
Device Status Check (set = actual)
For switching commands, a check takes place whether the selected switching device is already in the set/de-
sired position (set/actual comparison). This means, if a circuit breaker is already in the CLOSED position and
an attempt is made to issue a closing command, the command will be refused, with the operating message "set
condition equals actual condition". If the circuit breaker/switchgear device is in the intermediate position, then
this check is not performed.