GE 845 Instruction Manual page 260

PROTECTION
4–156
Table 4-42: IEC (BS) INVERSE TIME CURVE CONSTANTS
IEC (BS) CURVE SHAPE
IEC Curve A (BS142)
IEC Curve A (BS142)
IEC Curve A (BS142)
IEC Short Inverse
Table 4-43: IEC CURVE TRIP TIMES (IN SECONDS)
MULTIPLIER CURRENT (I/I
pickup
(TDM)
1.5 2.0
IEC CURVE A
0.05 0.860 0.501
0.10 1.719 1.003
0.20 3.439 2.006
0.40 6.878 4.012
0.60 10.317 6.017
0.80 13.755 8.023
1.00 17.194 10.029 6.302
IEC CURVE B
0.05 1.350 0.675
0.10 2.700 1.350
0.20 5.400 2.700
0.40 10.800 5.400
0.60 16.200 8.100
0.80 21.600 10.800 5.400
1.00 27.000 13.500 6.750
IEC CURVE C
0.05 3.200 1.333
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 INVERSE
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 formula:
K E
0.140 0.020
13.500 1.000
80.000 2.000
0.050 0.040
)
3.0 4.0 5.0 6.0
0.315 0.249 0.214 0.192
0.630 0.498 0.428 0.384
1.260 0.996 0.856 0.767
2.521 1.992 1.712 1.535
3.781 2.988 2.568 2.302
5.042 3.984 3.424 3.070
4.980 4.280 3.837
0.338 0.225 0.169 0.135
0.675 0.450 0.338 0.270
1.350 0.900 0.675 0.540
2.700 1.800 1.350 1.080
4.050 2.700 2.025 1.620
3.600 2.700 2.160
4.500 3.375 2.700
0.500 0.267 0.167 0.114
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
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS
t
r
9.7
43.2
58.2
0.500
7.0 8.0 9.0 10.0
0.176 0.165 0.156 0.149
0.353 0.330 0.312 0.297
0.706 0.659 0.623 0.594
1.411 1.319 1.247 1.188
2.117 1.978 1.870 1.782
2.822 2.637 2.493 2.376
3.528 3.297 3.116 2.971
0.113 0.096 0.084 0.075
0.225 0.193 0.169 0.150
0.450 0.386 0.338 0.300
0.900 0.771 0.675 0.600
1.350 1.157 1.013 0.900
1.800 1.543 1.350 1.200
2.250 1.929 1.688 1.500
0.083 0.063 0.050 0.040
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