Table 70. Harmonics-based earth-fault protection (HAEFPTOC)
Characteristic
Value
Operation accuracy
Depending on the frequency of the measured current: f
n
±2 Hz
±5% of the set value or ±0.004 × I
n
Start time
1)2)
Typically 77 ms
Reset time
Typically 40 ms
Reset ratio
Typically 0.96
Operate time accuracy in definite time mode
±1.0% of the set value or ±20 ms
Operate time accuracy in IDMT mode
3)
±5.0% of the set value or ±20 ms
Suppression of harmonics
-50 dB at f = f
n
-3 dB at f = 13 × f
n
1)
Fundamental frequency current = 1.0 × I
n
, harmonics current before fault = 0.0 × I
n
, harmonics fault current 2.0 ×
Start value, results based on statistical distribution of 1000 measurements
2)
Includes the delay of the signal output contact
3)
Maximum
Start value = 2.5 × I
n
,
Start value multiples in range of 2...20
Table 71. Harmonics-based earth-fault protection (HAEFPTOC) main settings
Parameter
Function
Value (Range)
Step
Start value
HAEFPTOC
0.05...5.00 × I
n
0.01
Time multiplier
HAEFPTOC
0.025...15.000
0.005
Operate delay time
HAEFPTOC
100...300000 ms
10
Operating curve type
1)
HAEFPTOC
Definite or inverse time
Curve type: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19
Minimum operate time
HAEFPTOC
100...200000 ms
10
1)
For further reference, see the Operation characteristics table
Table 72. Negative-sequence overcurrent protection (NSPTOC)
Characteristic
Value
Operation accuracy
Depending on the frequency of the measured current: f
n
±2 Hz
±1.5% of the set value or ±0.002 × I
n
Start time
1)2)
Minimum
Typical
Maximum
I
Fault
= 2 × set
Start value
I
Fault
= 10 × set
Start value
23 ms
15 ms
26 ms
18 ms
28 ms
20 ms
Reset time
Typically 40 ms
Reset ratio
Typically 0.96
Retardation time
<35 ms
Operate time accuracy in definite time mode
±1.0% of the set value or ±20 ms
Operate time accuracy in inverse time mode
±5.0% of the theoretical value or ±20 ms
3)
Suppression of harmonics
DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5,…
1)
Negative sequence current before fault = 0.0, f
n
= 50 Hz, results based on statistical distribution of 1000 measurements
2)
Includes the delay of the signal output contact
3)
Maximum
Start value = 2.5 × I
n
,
Start value multiples in range of 1.5...20
1MRS759144 A
REX640
Product version: 1
52
ABB
Summary of Contents for RELION REX640
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