ABB REG316 4 Series Operating Instructions Manual page 647

ABB Switzerland Ltd
Utility Automation
Numerical generator protection
Table 22: Inverse time ground fault overcurrent function (51N)
· Neutral current measurement (derived externally or internally)
· Stable response to transients
Inverse time characteristic
(acc. to B.S. 142 with extended setting range)
normal inverse
very inverse
extremely inverse
long time inverse
or RXIDG characteristic
Settings:
Number of phases
Base current I
B
Pick-up current I
start
Min. time setting t
min
k setting
1
Accuracy classes for the operating time
according to British Standard 142
RXIDG characteristic
Reset ratio
Table 23: Negative phase sequence current (46)
Features:
· Protection against unbalanced load
· Definite time delay
· Three-phase measurement
Settings:
Negative phase-sequence current (I
Delay
Accuracy of pick-up value
Reset ratio
I ³0.2 I
2 N
I <0.2 I
2 N
Starting time
Table 24: Instantaneous overvoltage prot. function (59, 27) with peak value evaluation
Features:
· Evaluation of instantaneous values, therefore extremely fast and frequency-independent on a wide scale
· Storing of the highest instantaneous value after start
· No suppression of d. c. components
· No suppression of harmonics
· 1- or 3phase
· Maximum value detection for multi-phase functions
· Variable lower limiting frequency f
Settings:
Voltage
Delay
Limiting f
min
Accuracy of pick-up value (at 0.08 to 1.1 f
Reset ratio
Max. trip time at no delay (at f
t = k / ((I/I
1
c = 0.02
c = 1
c = 2
c = 1
t = 5.8 - 1.35 · In (I/I
1 or 3
0.04 to 2.5 I
1 to 4 I in steps of 0.01 I
B
0 to 10 s in steps of 0.1 s
0.01 to 200 s in steps of 0.01 s
E 5.0
±4% (1 - I/80 I
>94%
) 0.02 to 0.5 I
2
0.5 to 60 s in steps of 0.01 s
±2% I (at f
N
>94%
>90%
£80 ms
min
0.01 to 2.0 U
0.00 to 60 s in steps of 0.01 s
25 to 50 Hz in steps of 1 Hz
) ±3% or ±0,005 U
N
>90% (for max. function)
<110% (for min. function)
) <30 ms (for max. function)
N
<50 ms (for min. function)
1MRK502004-Ben
C
) - 1)
B
)
B
in steps of 0.01 I
N N
B
)
B
in steps of 0.01 I
N N
, I £I
) (with measuring transformers)
N N
in steps of 0.01 U
N N
N
REG316*4
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