GlobalBaseSel: Selects the global base value group used by the function to define IBase,
VBase and SBase as applicable.
Operation: Disabled/Enabled
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 39: 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 Current 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
1MRK 506 369-UUS - Section 9
Current protection
Line distance protection REL670 2.2 ANSI 541
Application manual
To Next Page
Loading...
