Flexcurves - GE L90 Instruction Manual

5 SETTINGS
a) SETTINGS
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PATH: SETTINGS SYSTEM SETUP
# FLEXCURVE A
#
FlexCurves™ A through D have settings for entering times to Reset/Operate at the following pickup levels: 0.00 to 0.98 /
1.03 to 20.00. This data is converted into 2 continuous curves by linear interpolation between data points. To enter a cus-
tom FlexCurve™, enter the Reset/Operate time (using the
MESSAGE keys) for the desired protection curve (A, B, C, or D).
Table 5–3: 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. Special care must be applied when setting the two points that are close to the multiple of pickup of
1, i.e. 0.98 pu and 1.03 pu. It is recommended to set the two times to a similar value; otherwise, the linear
NOTE
approximation may result in undesired behavior for the operating quantity that is close to 1.00 pu.
GE Multilin
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FLEXCURVES

FLEXCURVE A(D)
FLEXCURVE A TIME AT
0.00 xPKP:
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
L90 Line Differential Relay
Range: 0 to 65535 ms in steps of 1
0 ms
VALUE keys) for each selected pickup point (using the
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
5.3 SYSTEM SETUP
5.3.6 FLEXCURVES™
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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