ABB REC650 Applications Manual page 205

1MRK 511 286-UUS A
Application manual
Line
protection
Operate time
Closed
Circuit
breaker
Open
Break time
Fault duration
Auto-reclosing
function
ANSI11000166 V1 EN
Figure 76: Single-shot automatic reclosing at a permanent fault
Three-phase automatic reclosing can be performed with or without the use of a
synchronism check, 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 end. If auto-
reclosing functions are included in duplicated line protection, which means two auto-
reclosing functions per CB, one should take measures to avoid uncoordinated reclosing
Operate time
Closing time
SMBRREC (79) open time for breaker
Set SMBRREC (79) open time
Section 10
Control
Break time
Fault duration
Reset time
ANSI11000166_1_en.vsd
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