GE B90 Instruction Manual page 364

GROUPED ELEMENTS
Table 5-26: IEC curve trip times (in seconds)
Multiplier Current ( I / I
(TDM)
1.5
IEC Curve A
0.05 0.860
0.10 1.719
0.20 3.439
0.40 6.878
0.60 10.317
0.80 13.755
1.00 17.194
IEC Curve B
0.05 1.350
0.10 2.700
0.20 5.400
0.40 10.800
0.60 16.200
0.80 21.600
1.00 27.000
IEC Curve C
0.05 3.200
5
0.10 6.400
0.20 12.800
0.40 25.600
0.60 38.400
0.80 51.200
1.00 64.000
IEC Short Inverse
0.05 0.153
0.10 0.306
0.20 0.612
0.40 1.223
0.60 1.835
0.80 2.446
1.00 3.058
IAC curves
The curves for the General Electric type IAC relay family are derived from the formulae:
where
T = operate time (in seconds)
TDM = Multiplier setting
I = Input current
I = Pickup Current setting
pkp
5-172
)
pickup
2.0 3.0 4.0
0.501 0.315 0.249
1.003 0.630 0.498
2.006 1.260 0.996
4.012 2.521 1.992
6.017 3.781 2.988
8.023 5.042 3.984
10.029 6.302 4.980
0.675 0.338 0.225
1.350 0.675 0.450
2.700 1.350 0.900
5.400 2.700 1.800
8.100 4.050 2.700
10.800 5.400 3.600
13.500 6.750 4.500
1.333 0.500 0.267
2.667 1.000 0.533
5.333 2.000 1.067
10.667 4.000 2.133
16.000 6.000 3.200
21.333 8.000 4.267
26.667 10.000 5.333
0.089 0.056 0.044
0.178 0.111 0.088
0.356 0.223 0.175
0.711 0.445 0.351
1.067 0.668 0.526
1.423 0.890 0.702
1.778 1.113 0.877
5.0 6.0 7.0
0.214 0.192 0.176
0.428 0.384 0.353
0.856 0.767 0.706
1.712 1.535 1.411
2.568 2.302 2.117
3.424 3.070 2.822
4.280 3.837 3.528
0.169 0.135 0.113
0.338 0.270 0.225
0.675 0.540 0.450
1.350 1.080 0.900
2.025 1.620 1.350
2.700 2.160 1.800
3.375 2.700 2.250
0.167 0.114 0.083
0.333 0.229 0.167
0.667 0.457 0.333
1.333 0.914 0.667
2.000 1.371 1.000
2.667 1.829 1.333
3.333 2.286 1.667
0.038 0.034 0.031
0.075 0.067 0.062
0.150 0.135 0.124
0.301 0.269 0.247
0.451 0.404 0.371
0.602 0.538 0.494
0.752 0.673 0.618
B90 LOW IMPEDANCE BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
8.0 9.0 10.0
0.165 0.156 0.149
0.330 0.312 0.297
0.659 0.623 0.594
1.319 1.247 1.188
1.978 1.870 1.782
2.637 2.493 2.376
3.297 3.116 2.971
0.096 0.084 0.075
0.193 0.169 0.150
0.386 0.338 0.300
0.771 0.675 0.600
1.157 1.013 0.900
1.543 1.350 1.200
1.929 1.688 1.500
0.063 0.050 0.040
0.127 0.100 0.081
0.254 0.200 0.162
0.508 0.400 0.323
0.762 0.600 0.485
1.016 0.800 0.646
1.270 1.000 0.808
0.029 0.027 0.026
0.058 0.054 0.052
0.115 0.109 0.104
0.231 0.218 0.207
0.346 0.327 0.311
0.461 0.435 0.415
0.576 0.544 0.518
Eq. 5-7