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5-212
T35 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
GROUPED ELEMENTS
CHAPTER 5: SETTINGS
5
I
2
t curves
The I
2
t curves are derived as follows:
Eq. 5-35
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 5-33: I
2
t curve trip times
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
1.00
44.44
25.00
11.11
6.25
4.00
2.78
2.04
1.56
1.23
1.00
10.00
444.44
250.00
111.11
62.50
40.00
27.78
20.41
15.63
12.35
10.00
100.00
4444.4
2500.0
1111.1
625.00
400.00
277.78
204.08
156.25
123.46
100.00
600.00
26666.7
15000.0
6666.7
3750.0
2400.0
1666.7
1224.5
937.50
740.74
600.00
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
Summary of Contents for T35
Page 9: ...TABLE OF CONTENTS T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL ix ABBREVIATIONS INDEX ...
Page 10: ...x T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL TABLE OF CONTENTS ...
Page 472: ...5 270 T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL TESTING CHAPTER 5 SETTINGS 5 ...
Page 596: ...iv T35 TRANSFORMER PROTECTION SYSTEM INSTRUCTION MANUAL ABBREVIATIONS ...