Table 36. Directional earth-fault protection (DEFxPDEF) main settings
Parameter
Function
Value (Range)
Step
Start Value
DEFLPDEF
0.010...5.000 x I
n
0.005
DEFHPDEF
0.10...40.00 x I
n
0.01
Directional mode
DEFLPDEF and DEFHPDEF
1=Non-directional
2=Forward
3=Reverse
Time multiplier
DEFLPDEF
0.05...15.00
0.01
DEFHPDEF
0.05...15.00
0.01
Operate delay time
DEFLPDEF
60...200000 ms
10
DEFHPDEF
40...200000 ms
10
Operating curve type
1)
DEFLPDEF
Definite or inverse time
Curve type: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19
DEFHPDEF
Definite or inverse time
Curve type: 1, 3, 5, 15, 17
Operation mode
DEFLPDEF and DEFHPDEF
1=Phase angle
2=IoSin
3=IoCos
4=Phase angle 80
5=Phase angle 88
1)
For further reference, refer to the Operating characteristics table
Table 37. Negative phase-sequence overcurrent protection (NSPTOC)
Characteristic
Value
Operation accuracy
Depending on the frequency of the current measured: f
n
±2 Hz
±1.5% of the set value or ±0.002 x I
n
Start time
1)2)
Minimum
Typical
Maximum
I
Fault
= 2 x set
Start value
I
Fault
= 10 x set
Start value
22 ms
14 ms
24 ms
16 ms
25 ms
17 ms
Reset time
< 40 ms
Reset ratio
Typical 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 x 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 x I
n
,
Start value multiples in range of 1.5 to 20
Transformer Protection and Control
1MRS757846 A
RET620
Product version: 2.0
ABB
31