Io>->, Io>>-> And Io - ABB REX 521 Technical Reference Manual, Standard Configurations

REX 521
7.1.3.
78
Protection Relay
Technical Reference Manual, Standard Configurations
Io>->, Io>>-> and Io>>>->
The directional earth-fault protection function blocks Io>->, Io>>-> and Io>>>->
are designed to be used for directional or non-directional earth-fault protection
whenever the DT characteristic or, as concerns Io>->, the IDMT (Inverse Definite
Minimum Time) characteristic is appropriate. Suppression of harmonics is possible.
Io>
CBFP
BACTRL
START
BS1
TRIP
BS2
CBFP
GROUP
RESET
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Directional earth-fault protection, low-set stage, Io>->
Start current
Start voltage
Operate time in DT mode
Time multiplier in IDMT mode
Operation mode
Operation criteria
Operation direction
Basic angle ϕ
b
Operation characteristic
Intermittent E/F
Measuring mode
Drop-off time of the operate time counter
Io>>
CBFP
BACTRL START
BS1 TRIP
BS2 CBFP
GROUP
RESET
1.0...25.0% of In
2.0...100.0% of Un
0.1...300.0 s
0.05...1.00
Not in use
Definite time
Extremely inverse
Very inverse
Normal inverse
Long time inverse
Basic angle & Uo
Basic angle
IoSin/Cos & Uo
IoSin/Cos
Non-directional Io
Non-directional Uo
Forward
Reverse
-90 °
-60 °
-30 °
0 °
IoSin( ϕ )
IoCos( ϕ )
Not active
Active
Peak-to-peak
Fundamental frequency
0...1000 ms
Note! The values below apply when f/fn = 0.95...1.05
1MRS 751802-MUM
Io>>>
CBFP
BACTRL
START
BS1
TRIP
BS2
CBFP
GROUP
RESET