10.3.2.14 Reclosing reclaim timer
The reclaim timer tReclaim defines the time it takes from issue of the reclosing
command, until the reclosing function resets. Should a new trip occur during this time,
it is treated as a continuation of the first fault. The reclaim timer is started when the CB
closing command is given.
10.3.2.15 Transient fault
After the Reclosing command the reclaim timer keeps running for the set time. If no
tripping occurs within this time, tReclaim, the Auto-Reclosing will reset. The CB
remains closed and the operating gear recharges. The input signals CBPOS and
CBREADY will be set
10.3.2.16 Permanent fault and reclosing unsuccessful signal
If a new trip occurs, and a new input signal START or TRSOTF appears, after the CB
closing command, the output UNSUCCL (unsuccessful closing) is set high. The timer
for the first shot can no longer be started. Depending on the set number of Reclosing
shots further shots may be made or the Reclosing sequence is ended. After reclaim
timer time-out the Auto-Reclosing function resets, but the CB remains open. The “CB
closed” information through the input CBPOS is missing. Thus, the reclosing function
is not ready for a new reclosing cycle.
Normally, the signal UNSUCCL appears when a new trip and start is received after the
last reclosing shot has been made and the auto-reclosing function is blocked. The
signal resets after reclaim reclaim time. The “unsuccessful” signal can also be made
to depend on CB position input. The parameter UnsucClByCBChk should then be set
to CB Check, and a timer tUnsucCl should be set too. If the CB does not respond to the
closing command and does not close, but remains open, the output UNSUCCL is set
high after time tUnsucCl. The Unsuccessful output can for example, be used in Multi-
Breaker arrangement to cancel the auto-reclosing function for the second breaker, if
the first breaker closed onto a persistent fault. It can also be used to generate a Lock-
out of manual closing until the operator has reset the Lock-out, see separate section.
10.3.2.17 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-Reclose function and connected to Binary IO as required. Many alternative
ways of performing the logic exist depending on whether manual 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:
1MRK 505 291-UEN A Section 10
Control
219
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