ABB REQ650 Applications Manual page 173

1MRK 505 383-UEN A
Breaker protection REQ650 2.2 IEC
Application manual
CircuitBreaker settings
CBReadyType: The selection depends on the type of performance available from
the circuit breaker operating gear. At setting OCO (circuit breaker ready for an
Open – Close – Open cycle), the condition is checked only at the start of the auto
reclosing cycle. The signal will disappear after tripping, but the circuit breaker will
still be able to perform the C-O sequence. For the selection CO (circuit breaker
ready for a Close – Open cycle) the condition is also checked after the set auto
reclosing dead time. This selection has a value first of all at multi-shot auto
reclosing to ensure that the circuit breaker is ready for a C-O sequence at shot two
and further shots. During single-shot auto reclosing, the OCO selection can be
used. A breaker shall according to its duty cycle always have storing energy for a
CO operation after the first trip. (IEC 56 duty cycle is O – 0.3sec – CO – 3min –
CO).
FollowCB: The usual setting is Follow CB = Off. The setting On can be used for
delayed auto reclosing with long delay, to cover the case when a circuit breaker is
being manually closed during the auto reclosing dead time before the auto recloser
has issued its breaker close command.
UnsucClByCBChk: The normal setting is NoCBCheck and the auto reclosing
unsuccessful event is then decided by a new trip within the reclaim time after the
last reclosing shot. If one wants to get the UNSUCCL (Reclosing is unsuccessful)
signal in the case the circuit breaker does not respond to the circuit breaker close
command, one can set UnsucClByCBCheck = CB Check and set tUnsucCl for
instance to 1.0 s.
BlockByUnsucCl: Setting of whether an unsuccessful auto reclosing attempt shall
set the auto recloser in blocked status. If used the BLKOFF input must be
configured to unblock the function after an unsuccessful auto reclosing attempt.
Normal setting is Off.
CutPulse: In circuit breakers without anti-pumping relays, the setting CutPulse =
On can be used to avoid repeated closing operation when reclosing onto a fault. A
new start will then cut the ongoing pulse.
tPulse: The circuit breaker closing command should be long enough to ensure
reliable operation of the circuit breaker. The circuit breaker closing command pulse
has a duration set by the tPulse setting. A typical setting may be tPulse = 200 ms.
A longer pulse setting may facilitate dynamic indication at testing, for example, in
debug mode of the Application Configuration Tool (ACT) in PCM600. In circuit
breakers without anti-pumping relays, the setting CutPulse = On can be used to
avoid repeated closing operations when reclosing onto a fault. A new start will then
cut the ongoing pulse.
tReclaim: The reclaim time sets the time for resetting the function to its original
state, after which a line fault and tripping will be treated as an independent new
case with a new auto reclosing cycle. One may consider a nominal CB duty cycle
of for instance, O – 0.3sec – CO – 3min – CO. However the 3 minute (180 s)
recovery time is usually not critical as fault levels are mostly lower than rated value
Section 9
Control
167