Lock-Out Initiation - ABB REC670 Applications Manual

Section 14
Control
14.2.2.19
334
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.

Lock-out initiation

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
different alternatives regarding what shall generate lock-out. Examples of questions
are:
• shall back-up time delayed trip give lock-out (normally yes)
• shall lock-out be generated when closing onto a fault (mostly)
• shall lock-out be generated when the auto recloser is Off at the fault or for
example, in single-phase auto recloser mode and the fault was multi-phase
(normally not as no closing attempt has been given)
• shall lock-out be generated if the circuit breaker did not have sufficient operating
power for an auto reclosing sequence (normally not as no auto closing attempt has
been given)
In Figures 115 and 116 the logic shows how a closing lock-out logic can be designed
with the lock-out relay as an external relay alternatively with the lock-out created
internally with the manual closing going through the synchrocheck function. An
example of lock-out logic.
1MRK 511 401-UUS A
M12391-214 v8
Bay control REC670 2.2 ANSI
Application manual