ABB RET 541 Product Manual page 23

Transformer Terminal
Directional earth-fault protection, low-set stage, DEF2Low, I
Start current
Start voltage
Operate time at DT mode
Time multiplier at IDMT mode
Operation mode
Operation criteria
Operation direction
Basic angle 
b
Operation characteristic
Intermittent E/F
Measuring mode
Drop-off time of the operate time counter
Operation accuracy
Start time:
- Injected neutral current and residual voltage
- internal time
- total time
Reset time
Reset ratio, typically
Retardation time
Operate time accuracy at DT mode
Accuracy class index E at IDMT mode
RET 541, RET 543, RET 545
>
0
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()
IoCos()
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
>2.0 x start current and
residual voltage >2.0 x start voltage
<72 ms
< 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
1MRS755543
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