ABB REB670 Applications Manual page 343

1MRK 505 370-UUS A
Busbar protection REB670 2.2 ANSI
Application manual
General settings
Operation: The operation of the auto recloser can be switched Enabled or Disabled.
ExternalCtrl: This setting makes it possible to switch the auto recloser On or Off using
an external switch via IO or communication ports.
ARMode: There are six different possibilities in the selection of auto reclosing
programs. The type of auto reclosing used for different kinds of faults depends on the
power system configuration and the users practices and preferences. When the circuit
breaker only have three-pole operation, then three-pole auto reclosing has to be chosen.
This is usually the case in sub-transmission and distribution lines. Three-pole tripping
and reclosing for all types of faults is also widely accepted in completely meshed
power systems. In transmission systems with few parallel circuits, single-pole
reclosing for single-phase faults is an attractive alternative for maintaining service and
system stability.
AutoContinue: Automatic continuation to the next shot if the circuit breaker is not
closed within the set time of tAutoContWait. The normal setting is AutoContinue =
Disabled.
tAutoContWait: This is the length in time the auto recloser waits to see if the circuit
breaker is closed when AutoContinue is set to Enabled. Normally, the setting of
tAutoContWait can be 2 sec.
StartByCBOpen: The normal setting Disabled is used when the function is started by
protection trip signals. If set Enabled the start of the auto recloser is controlled by an
circuit breaker auxiliary contact.
LongStartInhib: Usually the protection trip command, used as an auto reclosing start
signal, resets quickly as the fault is cleared. A prolonged trip command may depend on
a circuit breaker failing to clear the fault. A protection trip signal present when the
circuit breaker is reclosed will result in a new trip. The user can set a maximum start
pulse duration time tLongStartInh. This start pulse duration time is controlled by the
LongStartInhib setting. When the start pulse duration signal is longer than set
maximum start pulse duration, the auto reclosing sequence interrupts in the same way
as for a signal to the INHIBIT input.
tLongStartInh: The user can set a maximum start pulse duration time tLongStartInh. At
a set time somewhat longer than the auto reclosing dead time, this facility will not
influence the auto reclosing. A typical setting of tLongStartInh could be close to the
auto reclosing dead time.
tInhibit: To ensure reliable interruption and temporary blocking of the auto recloser a
resetting time delay tInhibit is used. The auto recloser will be blocked this time after
the deactivation of the INHIBIT input. A typical resetting delay is 5.0 s.
Section 12
Control
337