Woodward highprotec MRI4, User Manual

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Supervision
Tabular Summary
Supervision Schemes
Where? Within [Protection Para\Global Prot Para\Supervision\CBF]
CB Pos
2)
50BF
3)
CBPos und 50BF
4)
Which breaker is to be
monitored?
Where to select?
Within [Protection Para\Global Prot
Para\Supervision\CBF]
Selection of the breaker
that is to be monitored.
(In case that more than one
breaker is available)
Selection of the breaker
that is to be monitored.
(In case that more than one
breaker is available)
Selection ot the breaker
that is to be monitored.
(In case that more than one
breaker is available)
Trigger Modi
(Who starts the CBF-timer ?)
Where to set?
Within [Protection Para\Global Prot
Para\Supervision\CBF]
All Trips 5)
or
All Current Trips 5)
or
External Trips 5)
…and the breaker is in the
closed position and the CBF
module is within the stand-by
state.
All Trips 5)
or
All Current Trips 5)
or
External Trips 5)
...and the CBF module is within
the stand-by state.
All Trips 5)
or
All Current Trips 5)
or
External Trips 5)
…and the breaker is in the
closed position and the CBF
module is within the stand-by
state.
Who stops the CBF-Timer?
Once the timer has been stopped the
CBF module will switch into the state
„Rejected“. The module will switch
back into the state „Stand-by“ if the
trigger signals are dropped.
Position indicators
indicate that the
switchgear (breaker) is in
the open position. Current is fallen below the
I<-threshold
1) .
Position indicators
indicate that the
switchgear (breaker) is in
the open position and
current is fallen below the
I<-threshold
1)
.
A Breaker Failure will be
detected
...and a trip signal to the upstream
breaker will be issued?
When the CBF-Timer has
run down (elapsed). When the CBF-Timer has
run down (elapsed). When the CBF-Timer has
run down (elapsed).
When does the trip signal to
the upstream breaker drops
(falls back)?
If the position indicators
indicate that the
switchgear (breaker) is in
the open position and if
the trigger signals are
dropped (fallen back) If the current is fallen
below the I< and if the
trigger signals are
dropped (fallen back) If the position indicators
indicate that the
switchgear (breaker) is in
the open position and if
the current is fallen below
the I< and if the trigger
signals are dropped
(fallen back)
1) It is recommended to set the I< threshold to a value that is slightly below the fault current that is expectable.
By means of that it is possible to shorten the CBF supervision timer and hence reduce thermal and mechanical
damage of the electrical equipment in case of a breaker failure. The lower the threshold, the longer the time that is
needed to detect, that the breaker is in the open position, especially if there are transients/harmonics.
Note: Tripping delay of the
CBF module = Minimum delay time (tripping time) of the backup protection!
561 MRI4 DOK-HB-MRI4-2E