to generate a lock-out of manual circuit breaker closing until the operator has reset the
lock-out, see separate section.
15.2.2.19 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 309 and 310 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.
Lock-out
RXMD1
11
12
21
MAIN ZAK CLOSE
CLOSE COMMAND
SMBO
OR
SMBRREC (79)
OR
CCRBRF (50BF)
BJ-TRIP
ZCVPSOF-TRIP
INHIBIT
UNSUCCL
TRBU
ANSI05000315_2_en.vsd
SET
RESET
ELECTRICAL RESET
RELAY
ANSI05000315 V2 EN
Figure 309: Lock-out arranged with an external lock-out relay
Section 15 1MRK 506 369-UUS -
Control
664 Line distance protection REL670 2.2 ANSI
Application manual
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