Function Block - ABB RELION REX640 Technical Manual

Section 9
Control functions
9.9.2
9.9.3
9.9.3.1
1504

Function block

GUID-30A11971-5D98-40C0-909D-CAEEC8729DB5 V1 EN
Figure 787: Function block
Functionality
About 80 to 85 percent of faults in the MV overhead lines are transient and
automatically cleared with a momentary de-energization of the line. The rest of the
faults, 15 to 20 percent, can be cleared by longer interruptions. The de-energization of
the fault location for a selected time period is implemented through automatic
reclosing, during which most of the faults can be cleared.
In case of a permanent fault, the automatic reclosing is followed by final tripping. A
permanent fault must be located and cleared before the fault location can be re-
energized.
The autoreclosing function DARREC can be used with any circuit breaker suitable for
autoreclosing. The function provides five programmable autoreclosing shots which
can perform one to five successive autoreclosings of desired type and duration, for
instance one high-speed and one delayed autoreclosing.
When the reclosing is initiated with starting of the protection function, the
autoreclosing function can execute the final trip of the circuit breaker in a short operate
time, provided that the fault still persists when the last selected reclosing has been
carried out.
Protection signal definition
The Control line setting defines which of the initiation signals are protection start and
trip signals and which are not. With this setting, the user can distinguish the blocking
signals from the protection signals. The Control line setting is a bit mask, that is, the
lowest bit controls the INIT_1 line and the highest bit the INIT_6 line. Some
example combinations of the Control line setting are as follows:
1MRS759142 C
REX640
Technical Manual