pulse (trip), the breaker closing command pulse is then cut (interrupted). The minimum
breaker closing command pulse length is always 50ms. At the issue of the breaker
closing command, the appropriate auto recloser operation counter is incremented.
There is a counter for each type of auto reclosing command and one for the total
number of auto reclosing commands.
12.2.2.17 Transient fault
M12391-208 v4
After the breaker closing command the reclaim timer keeps running for the set
tReclaim time. If no start (trip) occurs within this time, the auto recloser will reset. The
circuit breaker remains closed and the operating gear rechar
ges. The CBCLOSED and
CBREADY input signals will be set.
12.2.2.18 Permanent fault and reclosing unsuccessful signal
M12391-211 v5
If a new start occurs, and the number of auto reclosing shots is set to 1, and a new
START or TRSOTF input signal appears, after the circuit breaker closing command, the
UNSUCCL output (unsuccessful reclosing) is set high. The timer for the first shot can
no longer be started. Depending on the set number of auto reclosing shots further shots
may be made or the auto reclosing sequence is ended. After reclaim timer time-out the
auto recloser resets, but the circuit breaker remains open. The circuit breaker closed
information through the CBCLOSED input is missing. Thus, the auto recloser is not
ready for a new auto reclosing cycle. Normally, the UNSUCCL output appears when a
new start is received after the last auto reclosing shot has been made and the auto
recloser is inhibited. The output signal resets after reclaim time. The “unsuccessful”
signal can also be made to depend on the circuit breaker position input. The
UnsucClByCBChk setting should then be set to CBCheck, and the tUnsucCl timer
should be set too. If the circuit breaker does not respond to the breaker closing
command and does not close, but remains open, the UNSUCCL output is set high after
the set tUnsucCl time. The UNSUCCL output can for example, be used in multi-
breaker arrangement to cancel the auto reclosing for the second circuit breaker, if the
first circuit breaker closed onto a persistent fault. It can also be used to generate a lock-
out of manual circuit breaker closing until the operator has reset the lock-out, see
separate section.
12.2.2.19 Lock-out initiation
M12391-214 v8
In many cases there is a requirement that a lock-out is generated when the auto
reclosing attempt fails. This is done with logic connected to the in- and outputs of the
auto recloser and connected to binary I/O as required. Many alternative ways of
performing the logic exist depending on whether manual circuit breaker closing is
interlocked in the IED, whether an external physical lock-out relay exists and whether
the reset is hardwired, or carried out by means of communication. There are also
Section 12 1MRK 505 370-UUS A
Control
324 Busbar protection REB670 2.2 ANSI
Application manual
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