ABB RED650 Technical Manual page 347

1MRK 505 394-UEN A
Line differential protection RED650 2.2 IEC
Technical manual
start
AND
AND
THOLHOLD
OR
inhibit
IEC16000159 V1 EN-US
Figure 158: Thermal protection hold
The auto recloser is set as master or slave in multi-breaker arrangements with
sequential reclosing with the setting Priority. The auto recloser for the first circuit
breaker, e.g. near the busbar, is set as master (when Priority=High) and the auto
recloser for the second circuit breaker is set as slave (when Priority=Low). While
the master is in progress, it issues the WFMASTER output. After an unsuccessful
reclosing the WFMASTER output is also maintained by the UNSUCCL output.
When activating the WAIT input, in the auto recloser set as slave, every dead timer
is changed to the value of setting tSlaveDeadTime and holds back the auto
reclosing operation. When the WAIT input is reset at the time of a successful
reclosing of the first circuit breaker, the slave is released to continue the reclosing
sequence after the set tSlaveDeadTime. The reason for shortening the time, for the
normal dead timers with the value of tSlaveDeadTime, is to give the slave
permission to react almost immediately when the WAIT input resets. The mimimum
settable time for tSlaveDeadTime is 0.1sec because both master and slave should
not send the breaker closing command at the same time. The slave should take the
duration of the breaker closing time of the master into consideration before sending
the breaker closing command. A setting tWaitForMaster sets a maximum wait time
for the WAIT input to reset. If the wait time expires, the reclosing cycle of the slave
is inhibited. The maximum wait time, tWaitForMaster for the second circuit
breaker is set longer than the auto reclosing dead time plus a margin for
synchrocheck conditions to be fulfilled for the first circuit breaker. Typical setting
is 2sec. In single circuit breaker applications, the setting Priority is set to None.
The logic for master-slave is shown in Figure 159.
inhibitThermalStart
S
R
-1
20ms
q
AND
Section 12
Control
startThermal
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