ABB REQ650 User Manual

It is from practical and economical reason not feasible to duplicate the circuit breaker
for the protected component. Instead a breaker failure protection is used.
The Breaker failure protection, phase segregated activation and output (CSPRBRF )
issues a back-up trip command to adjacent circuit breakers in case of failure to trip of
the “normal” circuit breaker for the protected component. The detection of failure to
break the current through the breaker is made by means of current measurement or as
detection of remaining trip signal (unconditional).
CSPRBRF can also give a re-trip. This means that a second trip signal is sent to the
protected circuit breaker. The re-trip function can be used to increase the probability
of operation of the breaker, or it can be used to avoid back-up trip of many breakers
in case of mistakes during relay maintenance and test.
6.10.3 Setting guidelines
The parameters for Breaker failure protection, phase segregated activation and output
CSPRBRF are set via the local HMI or PCM600.
The following settings can be done for the breaker failure protection, phase segregated
activation and output. Common base IED values for primary current (IBase), primary
voltage (UBase) and primary power (setting SBase) are set in a Global base values for
settings function GBASVAL. Setting GlobalBaseSel is used to select a GBASVAL
function for reference of base values.
Operation: Off/On
FunctionMode: This parameter can be set Current/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 CB Pos Check
means re-trip is done without check of breaker position.
1MRK 505 291-UEN A Section 6
Current protection
137
Application manual

ABB REQ650 Specifications

General

Brand	ABB
Model	REQ650
Category	Protection Device
Language	English