CBF_1:
Enabled
[ 040 055 ]
CBF_1:
Not ready
[ 040 025 ]
CBF_1:
Blocking EXT
[ 038 058 ]
CBF_1:
t2
[ 022 166 ]
CBF_1:
Delay/starting trig.
[ 022 155 ]
CBF_1:
Delay/fault beh. CB
[ 022 171 ]
CBF_1:
Delay/CB sync.superv
[ 022 172 ]
CBF_1:
t1 3p
[ 022 165 ]
64Z1102B
blocked
blocked
blocked
blocked
blocked
&
&
CBF_1:
Ready
[ 038 009 ]
Fig. 3-160: CBF readiness
3.31.6 Detecting a CB Tripping
A break in current flow is the preferred criterion to detect a successful CB
tripping. Protection functions that have triggering criteria not directly dependent
on current flow (e.g. V<>), may additionally be provided with status signals from
CB auxiliary contacts for evaluation.
3.31.7 Current flow monitoring
The current flow monitoring function is used to detect a break in current flow
safely, immediately and pole selectively. The CBF function continuously
compares sampled current values from the selected end with the set threshold
value CBF_1: I<. As long as current flow criteria are met the phase-selective
signals CBF_1: Current flow A, CBF_1: Current flow B, CBF_1: Current
flow C and the multiple signal CBF_1: Current flow Phx will be continuously
issued.
In addition to this line-associated current flow monitoring function a residual
current monitoring function is available which can be enabled/disabled.
For this either the residual current value measured directly at the CT or the value
derived from the three phase currents may be used.
Note that this choice is only possible when a measuring input for the residual
current is available. As there is no measuring input for the residual current
available for end d, the internally derived value of the residual current is always
used in that case, regardless of the setting.
As long as a residual current exceeding the comparator threshold is flowing, the
current flow criterion is not met and the corresponding signal (CBF_1: Current
flow N) is issued. When the residual current monitoring function is disabled, no
monitoring is carried out and the CBF_1: Current flow N = No signal is issued
continuously.
P634
3 Operation
3-206 P634/EN M/R-42-A // P634‑311‑653
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