Settings Of Protection Functions - ABB REF 541 Product Manual

Feeder Terminal

Settings of protection functions

Three-phase non-directional overcurrent protection, low-set stage, NOC3Low, 3I> (51-1)
Start current
Operate time at DT mode
Time multiplier at IDMT mode
Operation mode
Measuring mode
Drop-off time of the operate time counter
Operation accuracy
Start time
Reset time
Reset ratio, typically
Retardation time
Operate time accuracy at DT mode
Accuracy class index E at IDMT mode
Three-phase non-directional overcurrent protection, high-set stage, NOC3High, 3I>> (51-2) and
instantaneous stage, NOC3Inst, 3I>>> (51-3)
Start current
Operate time
Operation mode
Measuring mode
Drop-off time of the operate time counter
Operation accuracy
Start time
Reset time
Reset ratio, typically
Retardation time
Operate time accuracy at DT mode
REF 541, REF 543, REF 545.
0.10...5.00 x In
0.05...300.00 s
0.05...1.00
Not in use
Definite time
Extremely inverse
Very inverse
Normal inverse
Long time inverse
RI-type inverse
RD-type inverse
IEEE Extremely inverse
IEEE Very inverse
IEEE Short time inverse
IEEE Short time extremely inverse
IEEE Long time extremely inverse
IEEE Long time very inverse
IEEE Long time inverse
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 or ±0.01 x In
Injected currents > 2.0 x start current:
internal time < 32 ms
total time < 40 ms
40...1000 ms (depends on the minimum pulse width set for
the trip output)
0.95
< 45 ms
±2% of set value or ±20 ms
Class index E = 5.0 or ±20 ms
0.10...40.00 x In
0.05...300.00 s
Not in use
Definite time
Instantaneous
Peak-to-peak
Fundamental frequency
0...1000 ms
Note! The values below apply when f/fn = 0.95...1.05
0.1...10 x In: ±2.5% of set value or ±0.01 x In
10...40 x In: ±5.0% of set value
Injected currents > 2.0 x start current:
internal time < 32 ms
total time < 40 ms
40...1000 ms (depends on the minimum pulse width set for
the trip output)
0.95
< 45 ms
±2% of set value or ±20 ms
1MRS750443-MBG
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