ABB REB670 - Page 222

FunctionMode This parameter can be set Current
or Contact. This states the way the
detection of failure of the breaker is performed. In the mode current the current
measurement is used for the detection. In the mode Contact the long duration of
breaker position signal is used as indicator of failure of the breaker. The mode Current/
Contact means that both ways of detections are activated. Contact mode can be usable
in applications where the fault current through the circuit breaker is small. This can be
the case for some generator protection application (for example reverse power
protection) or in case of line ends with weak end infeed.
RetripMode: This setting states how the re-trip function shall operate. Retrip Off means
that the re-trip function is not activated. CB Pos Check (circuit breaker position check)
and Current means that a phase current must be larger than the operate level to allow
re-trip. CB Pos Check (circuit breaker position check) and Contact means re-trip is
done when circuit breaker is closed (breaker position is used). No CBPos Check means
re-trip is done without any check of breaker position.
Table 32: Dependencies between parameters RetripMode and FunctionMode
RetripMode FunctionMode Description
Retrip Off N/A the re-trip function is not
activated
CB Pos Check Current re-trip is done if the phase
current is larger than the operate
level after re-trip time has
elapsed
Contact re-trip is done when auxiliary
contact position indicates that
breaker is still closed after re-trip
time has elapsed
Current/Contact both methods according to above
are used but taken into account
also I>BlkCont
No CBPos Check Current
re-trip is done without check of
current level
Contact re-trip is done without check of
auxiliary contact position
Current/Contact re-trip is done without check of
current level or auxiliary contact
position
BuTripMode: Back-up trip mode is given to state sufficient current criteria to detect
failure to break. For Curr
ent operation 2 out of 4 means that at least two currents, of
the three-phase currents and the residual current, shall be high to indicate breaker
failure. 1 out of 3 means that at least one current of the three-phase currents shall be
high to indicate breaker failure. 1 out of 4 means that at least one current of the three-
phase currents or the residual current shall be high to indicate breaker failure. In most
Section 7 1MRK 505 370-UUS A
Current protection
216 Busbar protection REB670 2.2 ANSI
Application manual