GE B90 Instruction Manual page 323

CHAPTER 5: SETTINGS
Table 5-17: FlexCurve table
Reset Time Reset
ms
0.00 0.68
0.05 0.70
0.10 0.72
0.15 0.74
0.20 0.76
0.25 0.78
0.30 0.80
0.35 0.82
0.40 0.84
0.45 0.86
0.48 0.88
0.50 0.90
0.52 0.91
0.54 0.92
0.56 0.93
0.58 0.94
0.60 0.95
0.62 0.96
0.64 0.97
0.66 0.98
The relay using a given FlexCurve applies linear approximation for times between the user-entered points. Take
care 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 can result in undesired
behavior for the operating quantity that is close to 1.00 pu.
5.4.3.2 FlexCurve configuration with EnerVista software
The EnerVista software allows for easy configuration and management of FlexCurves and their associated data points.
Prospective FlexCurves can be configured from a selection of standard curves to provide the best approximate fit, then
specific data points can be edited afterwards. Alternately, curve data can be imported from a specified file (.csv format) by
selecting the EnerVista Import Data From setting (Settings > System Setup > FlexCurves > FlexCurve).
Curves and data can be exported, viewed, and cleared by clicking the appropriate buttons. FlexCurves are customized by
editing the operating time (ms) values at pre-defined per-unit current multiples. Note that the pickup multiples start at zero
(implying the "reset time"), operating time below pickup, and operating time above pickup.
5.4.3.3 Recloser curve editing
Recloser curve selection is special in that recloser curves can be shaped into a composite curve with a minimum response
time and a fixed time above a specified pickup multiples. There are 41 recloser curve types supported. These definite
operating times are useful to coordinate operating times, typically at higher currents and where upstream and
downstream protective devices have different operating characteristics. The recloser curve configuration window shown
here appears when the Initialize From setting in the EnerVista software is set to "Recloser Curve" and the Initialize
FlexCurve button is clicked.
B90 LOW IMPEDANCE BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
Time Operate Time
ms ms
1.03
1.05
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
Operate Time Operate
ms
2.9 4.9
3.0 5.0
3.1 5.1
3.2 5.2
3.3 5.3
3.4 5.4
3.5 5.5
3.6 5.6
3.7 5.7
3.8 5.8
3.9 5.9
4.0 6.0
4.1 6.5
4.2 7.0
4.3 7.5
4.4 8.0
4.5 8.5
4.6 9.0
4.7 9.5
4.8 10.0
SYSTEM SETUP
Time Operate Time
ms ms
10.5
11.0
11.5
12.0
12.5
13.0
13.5
14.0
14.5
15.0
15.5
16.0
16.5
17.0
17.5
18.0
18.5
19.0
19.5
20.0
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