3I>-> And 3I - ABB REX 521 Technical Reference Manual, Standard Configurations

1MRS 751802-MUM
7.1.4.
Protection Relay
Technical Reference Manual, Standard Configurations
Operation accuracy
Start time
Reset time
Reset ratio, typically
Retardation time
Operate time accuracy in DT mode
Accuracy class index E in IDMT mode
Directional earth-fault protection, high-set stage, Io>>-> and instantaneous stage,
Io>>>->
Start current
Start voltage
Operate time
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
Operation accuracy
Start time
Reset time
Reset ratio, typically
Retardation time
Operate time accuracy in DT mode
3I>-> and 3I>>->
The directional overcurrent function blocks are designed for directional single-
phase, two-phase and three-phase overcurrent and short-circuit protection whenever
the DT characteristic or, as concerns 3I>->, the IDMT (Inverse Definite Minimum
Time) characteristic is appropriate. Suppression of harmonics is possible.
±2.5% of set value + 0.0005 x In
±2.5% of set value or + 0.01 x Un
Phase angle ±2 °
Injected neutral current > 2.0 x start current and
residual voltage > 2.0 x start voltage:
internal time < 72 ms
total time < 80 ms
40...1000 ms (depends on the minimum pulse width set
for the trip output)
0.95
< 50 ms
±2% of set value or ±20 ms
Class index E = 5.0 or ±20 ms
1.0...200.0% of In
2.0...100.0% of Un
0.1...300.0 s
Not in use
Definite time
Instantaneous
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
±2.5% of set value + 0.0005 x In
±2.5% of set value or + 0.01 x Un
Phase angle ±2 °
Injected neutral current > 2.0 x start current
and residual voltage > 2.0 x start voltage:
internal time < 72 ms
total time < 80 ms
40...1000 ms (depends on the minimum pulse width set
for the trip output)
0.95
< 50 ms
±2% of set value or ±20 ms
REX 521
79