of the line breakers. The dead time selected should be long enough to ensure a high
probability of arc de-ionization and successful reclosing.
For individual line breakers, auto-reclosing equipment or functions, the auto-
reclosing open time is used to determine line “dead time”. When simultaneous
tripping and reclosing at the two line ends occurs, auto-reclosing open time is
approximately equal to the line “dead time”. If the open time and dead time differ then,
the line will be energized until the breakers at both ends have opened.
Open
Closed
Operate time
Line
protection
Circuit
breaker
Break time
T
rip
c
om
m
an
d
C
on
ta
ct
s
se
pa
ra
te
d
A
re
e
xt
in
gu
is
h
er
s
Fault duration
SMBRREC open time for breaker
Fault duration
R
es
et
s
In
st
an
t o
f f
au
lt
O
pe
ra
te
s
Break time
Closing time
Operate time
F
a
ul
t
O
pe
ra
te
s
R
e
se
ts
C
lo
se
c
om
m
a
nd
C
on
ta
ct
c
lo
se
d
Set SMBRREC open time
Reclaim time
Auto-reclosing
function
S
ta
rt
S
M
B
R
R
E
C
R
e
cl
os
in
g
co
m
m
an
d
S
M
B
R
R
E
C
re
se
t
IEC09000204_1_en.vsd
IEC09000204 V1 EN
Figure 86:
Single-shot automatic reclosing at a permanent fault
Three-phase automatic reclosing can be performed with or without the use of a
synchrocheck, and an energizing check, such as dead line or dead busbar check.
For the individual line breakers and auto-reclosing equipment, the ”auto-reclosing
open time” expression is used. This is the dead time setting for the Auto-Recloser.
During simultaneous tripping and reclosing at the two line ends, auto-reclosing open
time is approximately equal to the line dead time. Otherwise these two times may
differ as one line end might have a slower trip than the other end which means that the
line will not be dead until both ends have opened.
If the fault is permanent, the line protection will trip again when reclosing is attempted
in order to clear the fault.
It is common to use one automatic reclosing function per line circuit-breaker (CB).
When one CB per line end is used, then there is one auto-reclosing function per line
Section 10
1MRK 505 291-UEN A
Control
198
Application manual
Summary of Contents for Relion REQ650
Page 1: ...Relion 650 series Breaker protection REQ650 Application manual ...
Page 2: ......
Page 20: ...14 ...
Page 26: ...20 ...
Page 48: ...42 ...
Page 82: ...76 ...
Page 90: ...84 ...
Page 160: ...154 ...
Page 178: ...172 ...
Page 264: ...258 ...
Page 288: ...282 ...
Page 302: ...296 ...
Page 330: ...324 ...
Page 338: ...332 ...
Page 339: ...333 ...