2.Blocking Signal From I>-> Stage To I>> Stage; 3.Circuit-Breaker Failure Protection - ABB REX 521 Technical Reference Manual, Standard Configurations

1MRS 751802-MUM
11.2.5.2.
11.2.5.3.
Protection Relay
Technical Reference Manual, Standard Configurations
REX 521
3I>
BS
3I>>
3I>>>
REX 521
3I>
Incoming feeder
3I>
(H02)
BS
3I>>
REX 521
3I>
3I>>
3I>>>
Outgoing feeder (H04)
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Blocking signal from I>-> stage to I>> stage
In addition to the blocking described in chapter 10.2.5.1. the blocking signal from
the directional overcurrent stage 3I>-> can be used for blocking the 3I>> stage of
the same relay. With this arrangement we can set the operating time of the 3I>>
shorter. External wiring is needed for this blocking. The start signal of the 3I>-> is
routed to the signal output SO1. The output is connected to the input DI9 which is
routing blocking signal to the BS1 input of the overcurrent stage 3I>> as described
in chapter 10.2.5.1.
Circuit-breaker failure protection
All of the current-based protection functions in the standard configuration H02
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 setting 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.
The CBFP signals from the protection functions are routed to the output signals via
the output switchgroups. These settings can be found in
Main menu\Configuration\Output SWGRP\CBFP. The CBFP signal is
BS
BS
REX 521
3I>
3I>>
BS
3I>>>
Bus sectionalizer (H03)
REX 521
REX 521
3I>
3I>>
3I>>>
REX 521
3I>
Incoming feeder
3I>
(H02)
3I>>
REX 521
3I>
3I>>
3I>>>
Outgoing feeder (H04)
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