GE Multilin 350 Series Instruction Manual page 175

CHAPTER 6: SETPOINTS
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
Courtesy of NationalSwitchgear.com
Multiplier (TDM) Current (I/Ipickup)
1.5 2.0
0.10 6.400 2.667
0.20 12.800 5.333
0.40 25.600 10.667 4.000
0.60 38.400 16.000 6.000
0.80 51.200 21.333 8.000
1.00 64.000 26.667 10.000 5.333
IEC Short Time
0.05 0.153 0.089
0.10 0.306 0.178
0.20 0.612 0.356
0.40 1.223 0.711
0.60 1.835 1.067
0.80 2.446 1.423
1.00 3.058 1.778
IAC Curves
The curves for the General Electric type IAC relay family are derived from the formulae:
where: T = trip time (seconds), M = multiplier setpoint, I = input current, I
setpoint, A to E = constants.
Table 7: GE Type IAC Inverse Curve Constants
IAC Curve Shape A
IAC Extreme Inverse 0.0040
IAC Very Inverse 0.0900
IAC Inverse 0.2078
IAC Short Inverse 0.0428
Table 8: IAC Curve Trip Times
Multiplier (TDM)
1.5 2.0
IAC Extremely Inverse
0.5 1.699 0.749
1.0 3.398 1.498
2.0 6.796 2.997
4.0 13.591 5.993
6.0 20.387 8.990
8.0 27.183 11.987 4.846
10.0 33.979 14.983 6.058
IAC Very Inverse
0.5 1.451 0.656
1.0 2.901 1.312
2.0 5.802 2.624
4.0 11.605 5.248
6.0 17.407 7.872
3.0 4.0 5.0 6.0
1.000 0.533 0.333 0.229
2.000 1.067 0.667 0.457
2.133 1.333 0.914
3.200 2.000 1.371
4.267 2.667 1.829
3.333 2.286
0.056 0.044 0.038 0.034
0.111 0.088 0.075 0.067
0.223 0.175 0.150 0.135
0.445 0.351 0.301 0.269
0.668 0.526 0.451 0.404
0.890 0.702 0.602 0.538
1.113 0.877 0.752 0.673
B C
0.6379 0.6200
0.7955 0.1000
0.8630 0.8000
0.0609 0.6200
3.0 4.0 5.0 6.0
0.303 0.178 0.123 0.093
0.606 0.356 0.246 0.186
1.212 0.711 0.491 0.372
2.423 1.422 0.983 0.744
3.635 2.133 1.474 1.115
2.844 1.966 1.487
3.555 2.457 1.859
0.269 0.172 0.133 0.113
0.537 0.343 0.266 0.227
1.075 0.687 0.533 0.453
2.150 1.374 1.065 0.906
3.225 2.061 1.598 1.359
S3 PROTECTION
7.0 8.0 9.0 10.0
0.167 0.127 0.100 0.081
0.333 0.254 0.200 0.162
0.667 0.508 0.400 0.323
1.000 0.762 0.600 0.485
1.333 1.016 0.800 0.646
1.667 1.270 1.000 0.808
0.031 0.029 0.027 0.026
0.062 0.058 0.054 0.052
0.124 0.115 0.109 0.104
0.247 0.231 0.218 0.207
0.371 0.346 0.327 0.311
0.494 0.461 0.435 0.415
0.618 0.576 0.544 0.518
= pickup current
pu
D E
1.7872 0.2461
–1.2885 7.9586
–0.4180 0.1947
–0.0010 0.0221
7.0 8.0 9.0 10.0
0.074 0.062 0.053 0.046
0.149 0.124 0.106 0.093
0.298 0.248 0.212 0.185
0.595 0.495 0.424 0.370
0.893 0.743 0.636 0.556
1.191 0.991 0.848 0.741
1.488 1.239 1.060 0.926
0.101 0.093 0.087 0.083
0.202 0.186 0.174 0.165
0.405 0.372 0.349 0.331
0.810 0.745 0.698 0.662
1.215 1.117 1.046 0.992
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