GE C70 - Page 397

CHAPTER 5: SETTINGS GROUPED ELEMENTS
C70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL 5-193
5
Table 5-30: GE type IAC curve trip times
I
2
t curves
The I
2
t curves are derived as follows:
Eq. 5-10
where
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
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
IAC curve shape A B C D E t
r