GE Multilin T35 Transformer Protection System 5-107
5 SETTINGS 5.4 SYSTEM SETUP
5
5.4.7 FLEXCURVES
a) SETTINGS
PATH: SETTINGS SYSTEM SETUP FLEXCURVES FLEXCURVE A(D)
FlexCurves A through D have settings for entering times to reset and operate at the following pickup levels: 0.00 to 0.98
and 1.03 to 20.00. This data is converted into two continuous curves by linear interpolation between data points. To enter a
custom FlexCurve, enter the reset and operate times (using the VALUE keys) for each selected pickup point (using the
MESSAGE UP/DOWN keys) for the desired protection curve (A, B, C, or D).
The relay using a given FlexCurve applies linear approximation for times between the user-entered points. Special
care must be applied when setting the two points that are close to the multiple of pickup of 1; that is, 0.98 pu and
1.03 pu. It is recommended to set the two times to a similar value; otherwise, the linear approximation may result in
undesired behavior for the operating quantity that is close to 1.00 pu.
FLEXCURVE A
FLEXCURVE A TIME AT
0.00 xPKP: 0 ms
Range: 0 to 65535 ms in steps of 1
Table 5–8: FLEXCURVE TABLE
RESET TIME
MS
RESET TIME
MS
OPERATE TIME
MS
OPERATE TIME
MS
OPERATE TIME
MS
OPERATE TIME
MS
0.00 0.68 1.03 2.9 4.9 10.5
0.05 0.70 1.05 3.0 5.0 11.0
0.10 0.72 1.1 3.1 5.1 11.5
0.15 0.74 1.2 3.2 5.2 12.0
0.20 0.76 1.3 3.3 5.3 12.5
0.25 0.78 1.4 3.4 5.4 13.0
0.30 0.80 1.5 3.5 5.5 13.5
0.35 0.82 1.6 3.6 5.6 14.0
0.40 0.84 1.7 3.7 5.7 14.5
0.45 0.86 1.8 3.8 5.8 15.0
0.48 0.88 1.9 3.9 5.9 15.5
0.50 0.90 2.0 4.0 6.0 16.0
0.52 0.91 2.1 4.1 6.5 16.5
0.54 0.92 2.2 4.2 7.0 17.0
0.56 0.93 2.3 4.3 7.5 17.5
0.58 0.94 2.4 4.4 8.0 18.0
0.60 0.95 2.5 4.5 8.5 18.5
0.62 0.96 2.6 4.6 9.0 19.0
0.64 0.97 2.7 4.7 9.5 19.5
0.66 0.98 2.8 4.8 10.0 20.0