ABB RET620 - 2.3.3 Sensors and Monitoring Functions

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