Figure 535: Master and slave scheme
If the AR unit is defined as a master by setting its terminal priority to high:
• The unit activates the CMD_WAIT output to the low priority slave unit whenever a
shot is in progress, a reclosing is unsuccessful or the BLK_RCLM_T input is active
• The CMD_WAIT output is reset one second after the reclose command is given or
if the sequence is unsuccessful when the reclaim time elapses.
If the AR unit is defined as a slave by setting its terminal priority to low:
• The unit waits until the master releases the BLK_RECL_T input (the CMD_WAIT
output in the master). Only after this signal has been deactivated, the reclose
time for the slave unit can be started.
• The slave unit is set to a lockout state if the BLK_RECL_T input is not released
within the time defined by the
Max wait time
setting , which follows the initiation
of an autoreclosing shot.
If the terminal priority of the AR unit is set to "none", the AR unit skips all these
actions.
9.4.3.4 Thermal overload blocking
An alarm or start signal from the thermal overload protection (T1PTTR) can be
routed to the input BLK_THERM to block and hold the reclose sequence. The
BLK_THERM signal does not affect the starting of the sequence. When the reclose
time has elapsed and the BLK_THERM input is active, the shot is not ready until
the BLK_THERM input deactivates. Should the BLK_THERM input remain active longer
than the time set by the setting
Max Thm block time
, the AR function goes to
lockout.
If the BLK_THERM input is activated when the auto wait timer is running, the auto
wait timer is reset and the timer restarted when the BLK_THERM input deactivates.
9.4.4 Operation principle
The function can be enabled and disabled with the
Operation
setting. The
corresponding parameter values are "On" and "Off". Setting
Operation
to "Off"
resets non-volatile counters.
The reclosing operation can be enabled and disabled with the
Reclosing operation
setting. This setting does not disable the function, only the reclosing functionality.
The setting has three parameter values: “On”, “External Ctl” and ”Off”. The setting
value “On” enables the reclosing operation and “Off” disables it. When the setting
value “External Ctl” is selected, the reclosing operation is controlled with the
RECL_ON input. AR_ON is activated when reclosing operation is enabled.
The operation of DARREC can be described using a module diagram. All the modules
in the diagram are explained in the next sections.
Control functions
1MRS757644 H
1014 620 series
Technical Manual
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