CHAPTER 5: SETTINGS
GROUPED ELEMENTS
N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
5-225
5
I
2
t curves
The I
2
t curves are derived as follows:
Eq. 5-13
where
T = Operate time (in seconds)
TDM = Multiplier setting
I = Input current
I
pickup
= Pickup Current setting
T
RESET
= reset time in seconds (assuming energy capacity is 100% and RESET is “Timed”)
Table 5-36: I
2
t curve trip times
8.0
27.183
11.987
4.846
2.844
1.966
1.487
1.191
0.991
0.848
0.741
10.0
33.979
14.983
6.058
3.555
2.457
1.859
1.488
1.239
1.060
0.926
IAC Very Inverse
0.5
1.451
0.656
0.269
0.172
0.133
0.113
0.101
0.093
0.087
0.083
1.0
2.901
1.312
0.537
0.343
0.266
0.227
0.202
0.186
0.174
0.165
2.0
5.802
2.624
1.075
0.687
0.533
0.453
0.405
0.372
0.349
0.331
4.0
11.605
5.248
2.150
1.374
1.065
0.906
0.810
0.745
0.698
0.662
6.0
17.407
7.872
3.225
2.061
1.598
1.359
1.215
1.117
1.046
0.992
8.0
23.209
10.497
4.299
2.747
2.131
1.813
1.620
1.490
1.395
1.323
10.0
29.012
13.121
5.374
3.434
2.663
2.266
2.025
1.862
1.744
1.654
IAC Inverse
0.5
0.578
0.375
0.266
0.221
0.196
0.180
0.168
0.160
0.154
0.148
1.0
1.155
0.749
0.532
0.443
0.392
0.360
0.337
0.320
0.307
0.297
2.0
2.310
1.499
1.064
0.885
0.784
0.719
0.674
0.640
0.614
0.594
4.0
4.621
2.997
2.128
1.770
1.569
1.439
1.348
1.280
1.229
1.188
6.0
6.931
4.496
3.192
2.656
2.353
2.158
2.022
1.921
1.843
1.781
8.0
9.242
5.995
4.256
3.541
3.138
2.878
2.695
2.561
2.457
2.375
10.0
11.552
7.494
5.320
4.426
3.922
3.597
3.369
3.201
3.072
2.969
IAC Short Inverse
0.5
0.072
0.047
0.035
0.031
0.028
0.027
0.026
0.026
0.025
0.025
1.0
0.143
0.095
0.070
0.061
0.057
0.054
0.052
0.051
0.050
0.049
2.0
0.286
0.190
0.140
0.123
0.114
0.108
0.105
0.102
0.100
0.099
4.0
0.573
0.379
0.279
0.245
0.228
0.217
0.210
0.204
0.200
0.197
6.0
0.859
0.569
0.419
0.368
0.341
0.325
0.314
0.307
0.301
0.296
8.0
1.145
0.759
0.559
0.490
0.455
0.434
0.419
0.409
0.401
0.394
10.0
1.431
0.948
0.699
0.613
0.569
0.542
0.524
0.511
0.501
0.493
Multiplier
(TDM)
Current ( I / I
pickup
)
1.5
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
0.01
0.44
0.25
0.11
0.06
0.04
0.03
0.02
0.02
0.01
0.01
0.10
4.44
2.50
1.11
0.63
0.40
0.28
0.20
0.16
0.12
0.10
Multiplier
(TDM)
Current ( I / I
pickup
)
1.5
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0