ABB Relion 630 Series RET630 Product Manual page 37

ABB
Transformer Protection and Control
RET630
Product version: 1.1
Table 38. Stabilized restricted earth-fault protection (LREFPNDF)
Characteristic
Operation accuracy
1)2)
Start time
Reset time
Reset ratio
Retardation time
Operate time accuracy in definite time mode
Suppression of harmonics
1) Current before fault = 0.0 × I
2) Includes the delay of the signal output contact
Table 39. Stabilized restricted earth-fault protection (LREFPNDF) main settings
Parameter
Operate value
Restraint mode
Start value 2.H
Minimum operate
time
I = 2.0 × set
Fault
Operate valueI =
Fault
10.0 × set Operate
value
, f = 50 Hz
n n
Function
LREFPNDF
LREFPNDF
LREFPNDF
LREFPNDF
Value
At the frequency f = f
n
±1.5% of the set value or ±0.002 × I
Typical 18 ms (±5 ms)
Typical 12 ms (±5 ms)
< 50 ms
Typical 0.96
< 35 ms
±1.0% of the set value or ±20 ms
DFT: -50 dB at f = n × f
5, ...
Value (Range)
5...50 %
None
2nd harmonic
10...50 %
0.040...300.000 s
1MRS756978 D
Issued: 2011-05-18
n
, where n = 2, 3, 4,
n
Step
1
-
1
0.001
37