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DMC3S - Manual - 08 - 2021
Rapd rec slow reclosing
and subsequent memorized
reclosings
Rapid+slow+memorized reclosing program (79 Mode = Rapid+slow, N.DAR = 1..5).
Figure 5 below shows a rapid reclosing followed by a fault which opens the breaker within the neu-
tralisation time, followed by a slow reclosing and a fault detected beyond
t
dl
but within the neutrali-
sation time
t
r
; when
t
r
times out, the memorized reclosing is run.
If
t
d
=0; if the fault occurs immediately, the sequence proceeds with a non-definitive trip and wait for
the first memorized reclosing.
If the fault occurs within
t
r
, the sequence opens the breaker and the following memorized reclosing is
run when
t
r
expires. Every subsequent memorized reclosing starts timers
t
r
and
t
dm
. If a fault occurs
within
t
r
, but after
t
dm
, the sequence opens the breaker and the next memorized reclosing occurs
when
t
r
expires; if, on the other hand, the fault is detected within
t
dm
, a definitive trip occurs and an
unsuccessful reclosing is reported.
CB CLOSED CB OPEN
CB OPEN
CB OPEN
CB CLOSED
CB CLOSED
CB CLOSED
trdt
CB State
Rapid reclosing
t
tsdt
Neutralisation timer
Discrimination timer
tdl
tdm
Failed reclosing
tr (trf or trt)
tr (trf or trt)
tr (trf or trt)
Slow reclosing
Memorized reclosing
Figure 5 - Rapid reclosing followed by fault and subsequent slow and memorized reclosings
