GE L90 Instruction Manual page 314

5.6 GROUPED ELEMENTS
IAC CURVES:
The curves for the General Electric type IAC relay family are derived from the formulae:
A
TDM
T =
where: T = operate time (in seconds), TDM = Multiplier setting, I = Input current, I
constants, t
r
and is "Timed")
RESET
Table 5–22: GE TYPE IAC INVERSE TIME CURVE CONSTANTS
IAC CURVE SHAPE
IAC Extreme Inverse
IAC Very Inverse
IAC Inverse
IAC Short Inverse
Table 5–23: IAC CURVE TRIP TIMES
MULTIPLIER
(TDM)
1.5
IAC EXTREMELY INVERSE
0.5 1.699
5
1.0 3.398
2.0 6.796
4.0 13.591
6.0 20.387
8.0 27.183
10.0 33.979
IAC VERY INVERSE
0.5 1.451
1.0 2.901
2.0 5.802
4.0 11.605
6.0 17.407
8.0 23.209
10.0 29.012
IAC INVERSE
0.5 0.578
1.0 1.155
2.0 2.310
4.0 4.621
6.0 6.931
8.0 9.242
10.0 11.552
IAC SHORT INVERSE
0.5 0.072
1.0 0.143
2.0 0.286
4.0 0.573
6.0 0.859
8.0 1.145
10.0 1.431
5-168
B D
+ ----------------------------- - + ------------------------------------- -
I I – C
I I C
–
pkp
pkp
= characteristic constant, and T
A B
0.0040 0.6379
0.0900 0.7955
0.2078 0.8630
0.0428 0.0609
2.0 3.0 4.0
0.749 0.303 0.178
1.498 0.606 0.356
2.997 1.212 0.711
5.993 2.423 1.422
8.990 3.635 2.133
11.987 4.846 2.844
14.983 6.058 3.555
0.656 0.269 0.172
1.312 0.537 0.343
2.624 1.075 0.687
5.248 2.150 1.374
7.872 3.225 2.061
10.497 4.299 2.747
13.121 5.374 3.434
0.375 0.266 0.221
0.749 0.532 0.443
1.499 1.064 0.885
2.997 2.128 1.770
4.496 3.192 2.656
5.995 4.256 3.541
7.494 5.320 4.426
0.047 0.035 0.031
0.095 0.070 0.061
0.190 0.140 0.123
0.379 0.279 0.245
0.569 0.419 0.368
0.759 0.559 0.490
0.948 0.699 0.613
L90 Line Current Differential System
E
+ ------------------------------------- -
T
,
2 3
RESET
I I C
–
pkp
= reset time in seconds (assuming energy capacity is 100%
RESET
C D
0.6200 1.7872
0.1000 –1.2885
0.8000 –0.4180
0.6200 –0.0010
CURRENT ( I / I )
pickup
5.0 6.0 7.0
0.123 0.093 0.074
0.246 0.186 0.149
0.491 0.372 0.298
0.983 0.744 0.595
1.474 1.115 0.893
1.966 1.487 1.191
2.457 1.859 1.488
0.133 0.113 0.101
0.266 0.227 0.202
0.533 0.453 0.405
1.065 0.906 0.810
1.598 1.359 1.215
2.131 1.813 1.620
2.663 2.266 2.025
0.196 0.180 0.168
0.392 0.360 0.337
0.784 0.719 0.674
1.569 1.439 1.348
2.353 2.158 2.022
3.138 2.878 2.695
3.922 3.597 3.369
0.028 0.027 0.026
0.057 0.054 0.052
0.114 0.108 0.105
0.228 0.217 0.210
0.341 0.325 0.314
0.455 0.434 0.419
0.569 0.542 0.524
5 SETTINGS
t
r
=
------------------------------- -
TDM
2
1 I I
–
pkp
= Pickup Current setting, A to E =
pkp
E T
R
0.2461 6.008
7.9586 4.678
0.1947 0.990
0.0221 0.222
8.0 9.0 10.0
0.062 0.053 0.046
0.124 0.106 0.093
0.248 0.212 0.185
0.495 0.424 0.370
0.743 0.636 0.556
0.991 0.848 0.741
1.239 1.060 0.926
0.093 0.087 0.083
0.186 0.174 0.165
0.372 0.349 0.331
0.745 0.698 0.662
1.117 1.046 0.992
1.490 1.395 1.323
1.862 1.744 1.654
0.160 0.154 0.148
0.320 0.307 0.297
0.640 0.614 0.594
1.280 1.229 1.188
1.921 1.843 1.781
2.561 2.457 2.375
3.201 3.072 2.969
0.026 0.025 0.025
0.051 0.050 0.049
0.102 0.100 0.099
0.204 0.200 0.197
0.307 0.301 0.296
0.409 0.401 0.394
0.511 0.501 0.493
(EQ 5.12)
GE Multilin