GE M60 - Page 465

CHAPTER 5: SETTINGS GROUPED ELEMENTS
M60 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 5-257
5
Table 5-40: IEC curve trip times (in seconds)
IAC curves
The curves for the General Electric type IAC relay family are derived from the formulae:
Eq. 5-42
where
IEC Curve C (BS142) 80.000 2.000 58.2
IEC Short Inverse 0.050 0.040 0.500
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
IEC Curve A
0.05 0.860 0.501 0.315 0.249 0.214 0.192 0.176 0.165 0.156 0.149
0.10 1.719 1.003 0.630 0.498 0.428 0.384 0.353 0.330 0.312 0.297
0.20 3.439 2.006 1.260 0.996 0.856 0.767 0.706 0.659 0.623 0.594
0.40 6.878 4.012 2.521 1.992 1.712 1.535 1.411 1.319 1.247 1.188
0.60 10.317 6.017 3.781 2.988 2.568 2.302 2.117 1.978 1.870 1.782
0.80 13.755 8.023 5.042 3.984 3.424 3.070 2.822 2.637 2.493 2.376
1.00 17.194 10.029 6.302 4.980 4.280 3.837 3.528 3.297 3.116 2.971
IEC Curve B
0.05 1.350 0.675 0.338 0.225 0.169 0.135 0.113 0.096 0.084 0.075
0.10 2.700 1.350 0.675 0.450 0.338 0.270 0.225 0.193 0.169 0.150
0.20 5.400 2.700 1.350 0.900 0.675 0.540 0.450 0.386 0.338 0.300
0.40 10.800 5.400 2.700 1.800 1.350 1.080 0.900 0.771 0.675 0.600
0.60 16.200 8.100 4.050 2.700 2.025 1.620 1.350 1.157 1.013 0.900
0.80 21.600 10.800 5.400 3.600 2.700 2.160 1.800 1.543 1.350 1.200
1.00 27.000 13.500 6.750 4.500 3.375 2.700 2.250 1.929 1.688 1.500
IEC Curve C
0.05 3.200 1.333 0.500 0.267 0.167 0.114 0.083 0.063 0.050 0.040
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
IEC (BS) curve shape K E t
r