Siemens SIPROTEC 7SJ62 Manual page 266

Functions
2.14 Automatic Reclosing System 79
Blocking of Automatic Rreclosure via Internal Control
The auto-reclose function can be blocked, if control commands are issued via the integrated control function of
the device. The information must be routed via CFC (interlocking task-level) using the CMD_Information func-
tion block (see the following figure).
Figure 2-100
Zone Sequencing
Not available for models 7SJ62/64**-**A**-
At address 7140 ZONE SEQ.COORD., the zone sequencing feature can be turned ON or OFF.
If multiple reclosing operations are performed and the zone sequencing function is deactivated, only those re-
closing cycles are counted which the device has conducted after a trip command. With the zone sequencing
function switched on, an additional sequence counter also counts such auto-reclosures which (in radial sys-
tems) are carried out by relays connected on load side. This presupposes that the pickup of the 50-1/50N-1
elements drops out without a trip command being issued by a protective function initiating the auto-reclose
function. The parameters at addresses 7200 through 7247 (see paragraphs below at "Initiation and Blocking
of Reclosing by Protective Functions" and "Controlling Directional/Non-Directional Overcurrent Protection Ele-
ments via Cold Load Pickup") can thus be set to determine which protective elements are active or blocked
during what dead time cycles (for multiple reclosing attempts carried out by relays on the load side).
In the example shown in Figure "Zone sequencing with a fault occurring at Tap Line 5 and the busbar" (see
Figure 2-98) in the functional description, the zone sequencing was applied in the bus relay. Furthermore, as
from the second auto-reclosure the 50-2 elements (also applicable to the 50-3 elements) must be blocked, i.e.
address 7214 bef.2.Cy:50-2 must be set to blocked T=∞. The zone sequencing of the feeder relays is
switched off but the 50-2 elements must also be blocked after the second reclosing attempt. Moreover, it must
be ensured that the 50-2 elements start the automatic reclosing function: Set address 7152 50-2 to Starts
79.
Controlling Directional / Non-Directional Overcurrent Protection Elements via Dynamic Cold Load Pickup
The dynamic cold load pickup function provides a further alternative to control the protection via the automatic
reclosing system (see also Section 2.4). This function contains the parameter 1702 Start Condition It de-
termines the starting conditions for the increased setting values of current and time of the dynamic cold load
pickup that must apply for directional and non-directional overcurrent protection.
If parameter 1702 Start Condition is set to 79 ready, the directional and non-directional overcurrent pro-
tection always employ the increased setting values if the automatic reclosing system is ready. The auto-reclo-
sure function provides the signal 79 ready for controlling the dynamic cold load pickup. The signal 79 ready
is always active if the auto-reclosing system is available, active, unblocked and ready for another cycle. Control
via the dynamic cold load pickup function is non-cyclic.
Since control via dynamic cold load pickup and cyclic control via auto-reclosing system can run simultaneously,
the directional and non-directional overcurrent protection must coordinate the input values of the two interfaces.
In this context the cyclic auto-reclosing control has the priority and thus overwrites the release of the dynamic
cold load pickup function.
If the protective elements are controlled via the automatic reclosing function, changing the control variables
(e.g. by blocking) has no effect on elements that are already running. The elements in question are continued.
266
Blocking of the automatic reclose function using the internal control function
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008