ABB RELION REX640 - 4.3.3.12 Technical data; 4.3.4 Numerically stabilized low-impedance restricted earth-fault protection LREFPNDF (ANSI 87 NLI); 4.3.4.1 Identification; 4.3.4.2 Function block

Name Type Values (Range) Unit Description
IL1-bias:1 FLOAT32 0.00...80.00 Measured bias current
amplitude phase IL1
IL2-bias:1 FLOAT32 0.00...80.00 Measured bias current
amplitude phase IL2
IL3-bias:1 FLOAT32 0.00...80.00 Measured bias current
amplitude phase IL3
4.3.3.12 Technical data
Table 677: TR3PTDF Technical data
Characteristic Value
Operation accuracy Depending on the frequency of the measured current:
f
n
±2 Hz
±3.0% of the set value or ±0.002 × I
n
Start time
1, 2
Low stage
High stage
Minimum Typical Maximum
30 ms
17 ms
35 ms
18 ms
40 ms
20 ms
Reset time Typically 40 ms
Reset ratio Typically 0.96
Suppression of harmonics DFT: -50 dB at f = n × f
n
, where n = 2, 3, 4, 5, …
4.3.4 Numerically stabilized low-impedance restricted earth-
fault protection LREFPNDF (ANSI 87NLI)
4.3.4.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Numerically stabilized low-impe-
dance restricted earth-fault protec-
tion
LREFPNDF dIoLo> 87NLI
4.3.4.2 Function block
Figure 421: Function block
1
Current before fault = 0.0 × I
n
, f
n
= 50 Hz. Injected differential current = 2.0 × set operation value.
2
Measured with static power output (SPO)
Protection functions 1MRS759142 F
748 REX640
Technical Manual