CHAPTER 5: SETTINGS
GROUPED ELEMENTS
B30 BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
5-197
5
IAC curves
The curves for the General Electric type IAC relay family are derived from the formulae:
Eq. 5-7
where
T = operate time (in seconds)
TDM = Multiplier setting
I = Input current
I
pkp
= Pickup Current setting
A to E = constants defined in the table
t
r
= characteristic constant defined in the table
T
RESET
= reset time in seconds (assuming energy capacity is 100% and RESET is “Timed”)
Table 5-29: GE type IAC inverse time curve constants
Table 5-30: GE type IAC curve trip times
0.10
6.400
2.667
1.000
0.533
0.333
0.229
0.167
0.127
0.100
0.081
0.20
12.800
5.333
2.000
1.067
0.667
0.457
0.333
0.254
0.200
0.162
0.40
25.600
10.667
4.000
2.133
1.333
0.914
0.667
0.508
0.400
0.323
0.60
38.400
16.000
6.000
3.200
2.000
1.371
1.000
0.762
0.600
0.485
0.80
51.200
21.333
8.000
4.267
2.667
1.829
1.333
1.016
0.800
0.646
1.00
64.000
26.667
10.000
5.333
3.333
2.286
1.667
1.270
1.000
0.808
IEC Short Inverse
0.05
0.153
0.089
0.056
0.044
0.038
0.034
0.031
0.029
0.027
0.026
0.10
0.306
0.178
0.111
0.088
0.075
0.067
0.062
0.058
0.054
0.052
0.20
0.612
0.356
0.223
0.175
0.150
0.135
0.124
0.115
0.109
0.104
0.40
1.223
0.711
0.445
0.351
0.301
0.269
0.247
0.231
0.218
0.207
0.60
1.835
1.067
0.668
0.526
0.451
0.404
0.371
0.346
0.327
0.311
0.80
2.446
1.423
0.890
0.702
0.602
0.538
0.494
0.461
0.435
0.415
1.00
3.058
1.778
1.113
0.877
0.752
0.673
0.618
0.576
0.544
0.518
IAC curve shape
A
B
C
D
E
t
r
IAC Extreme Inverse
0.0040
0.6379
0.6200
1.7872
0.2461
6.008
IAC Very Inverse
0.0900
0.7955
0.1000
–1.2885
7.9586
4.678
IAC Inverse
0.2078
0.8630
0.8000
–0.4180
0.1947
0.990
IAC Short Inverse
0.0428
0.0609
0.6200
–0.0010
0.0221
0.222
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
IAC Extremely Inverse
0.5
1.699
0.749
0.303
0.178
0.123
0.093
0.074
0.062
0.053
0.046
1.0
3.398
1.498
0.606
0.356
0.246
0.186
0.149
0.124
0.106
0.093
2.0
6.796
2.997
1.212
0.711
0.491
0.372
0.298
0.248
0.212
0.185
4.0
13.591
5.993
2.423
1.422
0.983
0.744
0.595
0.495
0.424
0.370
6.0
20.387
8.990
3.635
2.133
1.474
1.115
0.893
0.743
0.636
0.556
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 b30
Page 10: ...x B30 BUS DIFFERENTIAL SYSTEM INSTRUCTION MANUAL TABLE OF CONTENTS ...
Page 486: ...5 278 B30 BUS DIFFERENTIAL SYSTEM INSTRUCTION MANUAL TESTING CHAPTER 5 SETTINGS 5 ...
Page 616: ...iv B30 BUS DIFFERENTIAL SYSTEM INSTRUCTION MANUAL ABBREVIATIONS ...
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