Table 38. Negative phase-sequence overcurrent protection (NSPTOC) main settings
Parameter
Function
Value (Range)
Step
Start value
NSPTOC
0.01...5.00 x I
n
0.01
Time multiplier
NSPTOC
0.05...15.00
0.01
Operate delay time
NSPTOC
40...200000 ms
10
Operating curve type
1)
NSPTOC
Definite or inverse time
Curve type: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19
1)
For further reference, see Operation characteristics table
Table 39. Residual overvoltage protection (ROVPTOV)
Characteristic
Value
Operation accuracy
Depending on the frequency of the voltage measured: f
n
±2 Hz
±1.5% of the set value or ±0.002 x U
n
Start time
1)2)
Minimum
Typical
Maximum
U
Fault
= 1.1 x set
Start value
55 ms
56 ms
58 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
Suppression of harmonics
DFT: -50 dB at f = n x f
n
, where n = 2, 3, 4, 5,…
1)
Residual voltage before fault = 0.0 x U
n
, f
n
= 50 Hz, residual voltage with nominal frequency injected from random phase angle, results based on statistical distribution of 1000
measurements
2)
Includes the delay of the signal output contact
Table 40. Residual overvoltage protection (ROVPTOV) main settings
Parameter
Function
Value (Range)
Step
Start value
ROVPTOV
0.010...1.000 x U
n
0.001
Operate delay time
ROVPTOV
40...300000 ms
1
Transformer Protection and Control
1MRS757846 A
RET620
Product version: 2.0
32
ABB
