GE Multilin
C70 Capacitor Bank Protection and Control System
5-119
5 SETTINGS
5.6 GROUPED ELEMENTS
5
IAC CURVES:
The curves for the General Electric type IAC relay family are derived from the formulae:
,
(EQ 5.9)
where:
T
= operate time (in seconds),
TDM
= Multiplier setting,
I
= Input current,
I
pkp
= Pickup Current setting,
A to
E
=
constants,
t
r
= characteristic constant, and
T
RESET
= reset time in seconds (assuming energy capacity is 100%
and
RESET
is “Timed”)
Table 5–17: GE TYPE IAC INVERSE TIME CURVE CONSTANTS
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
Table 5–18: IAC CURVE TRIP TIMES
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
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
T
TDM
A
B
I I
pkp
⁄
(
)
C
–
------------------------------
D
I I
pkp
⁄
(
)
C
–
(
)
2
--------------------------------------
E
I I
pkp
⁄
(
)
C
–
(
)
3
--------------------------------------
+
+
+
⎝
⎠
⎜
⎟
⎛
⎞
×
=
T
RESET
TDM
t
r
1
I I
pkp
⁄
(
)
2
–
--------------------------------
×
=
Summary of Contents for UR Series C70
Page 2: ......
Page 10: ...x C70 Capacitor Bank Protection and Control System GE Multilin TABLE OF CONTENTS ...
Page 344: ...5 220 C70 Capacitor Bank Protection and Control System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Page 586: ...D 10 C70 Capacitor Bank Protection and Control System GE Multilin D 1 OVERVIEW APPENDIXD D ...