Contact check criteria can be used where the fault current through the breaker is small.
Breaker failure protection, 3-phase activation and output (CCRBRF) current criteria
can be fulfilled by one or two phase currents the residual current, or one phase current
plus residual current. When those currents exceed the user defined settings, the
function is triggered. These conditions increase the security of the back-up trip
command.
CCRBRF function can be programmed to give a three-phase re-trip of the own breaker
to avoid inadvertent tripping of surrounding breakers.
8.5.3 Function block
CCRBRF
I3P*
BLOCK
START
CBCLDL1
CBCLDL2
CBCLDL3
TRBU
TRRET
IEC09000272_1_en.vsd
IEC09000272 V1 EN
Figure 108: CCRBRF function block
8.5.4 Signals
Table 108: CCRBRF Input signals
Name
Type Default Description
I3P GROUP
SIGNAL
- Three phase group signal for current inputs
BLOCK BOOLEAN 0 Block of function
START BOOLEAN 0 Three phase start of breaker failure protection
function
CBCLDL1 BOOLEAN 1 Circuit breaker closed in phase L1
CBCLDL2 BOOLEAN 1 Circuit breaker closed in phase L2
CBCLDL3 BOOLEAN 1 Circuit breaker closed in phase L3
Table 109: CCRBRF Output signals
Name
Type Description
TRBU BOOLEAN Back-up trip by breaker failure protection function
TRRET BOOLEAN Retrip by breaker failure protection function
Section 8 1MRK 502 048-UEN A
Current protection
222
Technical manual
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