91
DMC3S - Manual - 08 - 2021
—
Auto-reclose (79)
Preface
The reclosing function can be enabled with:
• The front panel switch,
• The ThySetter configuration software
• The IEC61850 comms protocol
A variety of reclosing sequences can be set, corresponding to:
• Rapid reclosing,
• Rapid reclosing followed by slow reclosing,
• Rapid reclosing following slow reclosing and one or more memorized reclosings (0...5).
The reclosing sequence is initiated following trip of the following protection functions to open the
breaker:
• 79-I>
Reclosing due to trip of threshold I> (50/51)
• 79-I>>
Reclosing due to trip of threshold I>> (50/51)
• 79-I>>>
Reclosing due to trip of threshold I>>> (50/51)
• 79I->>>>
Reclosing due to trip of threshold I>>>> (50/51)
• 79-IPD>
Reclosing due to trip of threshold IPD> (67)
• 79-IPD>>
Reclosing due to trip of threshold IPD>> (67)
• 79-IPD>>>
Reclosing due to trip of threshold IPD>>> (67)
• 79-IPD>>>> Reclosing due to trip of threshold IPD>>>> (67)
• 79-IE>
Reclosing due to trip of threshold IE> (50N/51N)
• 79-IE>>
Reclosing due to trip of threshold IE>> (50N/51N)
• 79-IE>>>
Reclosing due to trip of threshold IE>>> (50N/51N)
• 79-INe>
Reclosing due to trip of threshold INe> (51N(E))
• 79-INe>>
Reclosing due to trip of threshold INe>> (51N(E))
• 79-IED>
Reclosing due to trip of threshold IED> (67N)
• 79-IED>>a
Reclosing due to trip of threshold IED>>a (67N)
• 79-IED>>b
Reclosing due to trip of threshold IED>>b (67N)
• 79-IED>>>
Reclosing due to trip of threshold IED>>> (67N)
• 79-IED>>>> Reclosing due to trip of threshold IED>>>> (67N)
• 79-IED>>>>> Reclosing due to trip of threshold IED>>>>> (67N)
Symbols
The following parameters can be adjusted (in the menu
Set \ Auto-reclose - 79
):
• N.DAR
Number of memorized reclosings
• t
rdt
Rapid reclosing wait time
• t
sdt
Slow reclosing wait time
• t
rf
Neutralisation time
[1]
following trip due to phase fault
• t
rt
Neutralisation time following trip due to ground fault
• t
dr
Discrimination time
[2]
following rapid reclosing
• t
dl
Discrimination time following slow reclosing
• t
dm
Discrimination time following memorized reclosing
• t
d
Discrimination time following intentional reclosing
Rapid reclosing
Rapid reclosing program (79 Mode = Rapid).
Figure 1 below shows a successful rapid reclosing; no fault resulting in breaker opening during the
neutralisation time (
t
rf
or
t
rt
).
The automation returns to standby once the neutralisation timer has counted down, and a succes-
sive trip will activate rapid reclosing again.
Note 1 The neutralisation timer, which starts when the breaker closes, is a time during which no faults resulting in breaker opening may occur for the
reclosing to be considered to have terminated successfully
Note 2 The discrimination timer, which starts when the breaker closes, is a time during which no faults resulting in breaker opening may occur for
subsequent reclosing attempts to be permitted
CB CLOSED
CB OPEN
CB CLOSED
trdt
CB State
Neutralisation timer
t
tr (trf or trt)
Rapid reclosing
79 in standby
Figure 1 - Successful rapid reclosing
