ABB REX 521, Technical Reference Manual, Standard Configurations

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1MRS751802-MUM Protection Relay
Technical Reference Manual, Standard Configurations
REX 521
In this example the digital input DI8 is connected to the input signal BACTRL and
then routed to the BACTRL input of the directional earth fault functions. The
BACTRL signal can be found in
Main menu\Configuration\Input
Signals\BACTRL\
where DI8 is selected. The checksum for the switchgroup in
Main menu\Configuration\Input SWGRP\BACTRL\
should be 3 to
change the angle on Io>-> and Io>>->. Refer to the CD-ROM
Technical
Descriptions of Functions (see Section 1.5. Related documents) for more
information about the basic angle control (directional earth fault function).
10.1.4.2. Outgoing blocking signal to the incoming feeder
The start signals from any protection function can be routed to an output relay to
provide a blocking signal to the incoming feeder. The overcurrent stages 3I>> and
3I>>> have also a separate BSOUT signal for blocking purpose.
To use the start signal from a protection function, the signal has to be routed via
Main menu\Configuration\Output SWGRP\Start 1 or \Start 2
.
When the start signals have been routed, the output relay has to be selected in
Main menu\Configuration\Output Signals
. In this example the
overcurrent stage 3I>> is routed via Start 1 and then connected to the power output
2, PO2. The checksum in this application example for Start 1 is 2.
10.1.4.3. Trip-alarm signals from overcurrent and earth fault
The trip signals from any protection function can be routed to an output relay in
order to provide an alarm signal to indicate which protection has tripped.
To use the trip signal from a protection function, the signal has to be routed via
Main menu\Configuration\Output SWGRP\Trip 2
or
\Trip 3
.
When the trip signals have been routed, the output relay has to be selected in
Main menu\Configuration\Output Signals
.
In this example, the overcurrent stages 3I> and 3I>>> are routed via Trip 2, then
connected to the signal output 1, SO1. The earth fault stages Io>-> and Io>>-> are
routed via Trip 3, then connected to the signal output 2, SO2. The checksum in this
application example for Trip 2 is 5 and 24 for Trip 3.
10.1.4.4. Circuit-breaker failure protection
All of the protection functions in the standard configuration M01 provide a delayed
trip signal CBFP after the trip signal unless the fault has not disappeared during the
set CBFP time delay. In the circuit-breaker failure protection, the CBFP output can
be used for operating an upstream circuit breaker.
The settings for breaker failure are set separately for each protection function. For
example, to set the CBFP time for 3I>> go to
Main menu\Protection\3I>>\Control settings
where it is possible
to set the
CBFP time
from 100 ms to 1000 ms. The control parameter
Trip
pulse
sets the width of the trip output signal, but also of the CBFP output signal.