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CHAPTER 6: PROTECTION SETPOINTS
CURRENT ELEMENTS
850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–9
I
2
T CURVES
The curves for the I
2
t are derived from the formula:
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 6-10: I
2
T CURVE TRIP TIMES (IN SECONDS)
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
0.618
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
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
Summary of Contents for Multilin 850
Page 10: ...VIII 850 FEEDER PROTECTION SYSTEM INSTRUCTION MANUAL ...
Page 135: ...CHAPTER 3 INTERFACES SOFTWARE INTERFACE 850 FEEDER PROTECTION SYSTEM INSTRUCTION MANUAL 3 41 ...
Page 151: ...CHAPTER 3 INTERFACES SOFTWARE INTERFACE 850 FEEDER PROTECTION SYSTEM INSTRUCTION MANUAL 3 57 ...
Page 153: ...CHAPTER 3 INTERFACES SOFTWARE INTERFACE 850 FEEDER PROTECTION SYSTEM INSTRUCTION MANUAL 3 59 ...
Page 439: ...CHAPTER 7 MONITORING FUNCTIONS 850 FEEDER PROTECTION SYSTEM INSTRUCTION MANUAL 7 19 ...
Page 644: ...11 20 850 FEEDER PROTECTION SYSTEM INSTRUCTION MANUAL FLEXELEMENTS CHAPTER 11 METERING ...