ABB REX 521 - 3 I>-> and 3 I

1MRS751802-MUM
REX 521
93
Protection Relay
Technical Reference Manual, Standard Configurations
7.1.4. 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.
Fig. 7.1.4.-1 Function block symbols of 3I>-> and 3I>>-
Three-phase directional overcurrent protection, low-set stage, 3I>->
Start current 0.05…40.00 x In
Operate time 0.05…300.00 s
Operation mode Not in use
Definite time
Extremely inv
Very inverse
Normal inverse
Long-time inv.
RI-type inverse
RD-type inverse
Time multiplier 0.05...1.00
Basic angle ϕ
b
0...90
Oper. Direction Forward
Reverse
Earth fault pr. Disabled
Enabled
Measuring mode Mode1 (Phase-to-phase voltages/Peak-to-peak currents)
Mode2 (Phase-to-phase voltages/Fund. freq. Currents)
Mode3 (Phase-to-earth voltages/Peak-to-peak currents)
Mode4 (Phase-to-earth voltages/Fund. freq. Currents)
Drop-off time of the operate time counter 0...1000 ms
Note! The values below apply when f/fn = 0.95...1.05
Operation accuracy Current:
0.1...10 x In: ±2.5% of set value or ±0.01 x In
10...40 x In: ±5.0% of set value
Voltage:
±2.5% of measured value or ±0.01 x Un
Phase angle: ±2°
Start time Injected currents > 2.0 x start current:
internal time < 42 ms
total time < 50 ms
Reset time 40...1000 ms (depends on the minimum pulse width set
for the trip output)
Reset ratio, typically 0.95
Retardation time < 45 ms
Operate time accuracy in DT mode ±2% of set value or ±20 ms
CBFP
BACTRL
BS1
BS2
GROUP
RESET
STAR
T
TRI
P
CBF
P
3I>
CBFP
BACTRL
BS1
BS2
GROUP
DOUBLE
RESET
BSOUT
START
TRI
P
CBF
P
3I>>