GE 750 Instruction Manual page 131

S5 Protection
Table 5–8: IEC Curve Trip Times (in seconds)
Multiplier
(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
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
1.00 27.000 13.500
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
0.60 38.400 16.000
0.80 51.200 21.333
1.00 64.000 26.667
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
GE Multilin
IEC Curves:
For European applications, the relay offers the four standard curves defined in IEC
255-4 and British standard BS142. These are defined as IEC Curve A, IEC Curve B,
IEC Curve C, and Short Inverse. The formulae for these curves are:
T
where: T = trip time (seconds), M = multiplier setpoint, I = input current,
I = pickup current setpoint, K, E = constants.
pickup
Table 5–7: IEC (BS) Inverse Time Curve Constants
IEC (BS) Curve Shape
IEC Curve A (BS142)
IEC Curve B (BS142)
IEC Curve C (BS142)
IEC Short Inverse
Current ( I / I
3.0 4.0 5.0
0.315 0.249 0.214
0.630 0.498 0.428
1.260 0.996 0.856
2.521 1.992 1.712
3.781 2.988 2.568
5.042 3.984 3.424
6.302 4.980 4.280
0.338 0.225 0.169
0.675 0.450 0.338
1.350 0.900 0.675
2.700 1.800 1.350
4.050 2.700 2.025
5.400 3.600 2.700
6.750 4.500 3.375
0.500 0.267 0.167
1.000 0.533 0.333
2.000 1.067 0.667
4.000 2.133 1.333
6.000 3.200 2.000
8.000 4.267 2.667
10.000 5.333 3.333
0.056 0.044 0.038
0.111 0.088 0.075
0.223 0.175 0.150
0.445 0.351 0.301
0.668 0.526 0.451
0.890 0.702 0.602
1.113 0.877 0.752
http://www.GEmultilin.com
⎛ ⎞
K
M ×
⎜ ⎟
-------------------------------- -
=
E
⎝ ⎠
( I I ⁄ ) 1
–
pu
K E
0.140 0.020
13.500 1.000
80.000 2.000
0.050 0.040
)
pickup
6.0 7.0
0.192 0.176
0.384 0.353
0.767 0.706
1.535 1.411
2.302 2.117
3.070 2.822
3.837 3.528
0.135 0.113
0.270 0.225
0.540 0.450
1.080 0.900
1.620 1.350
2.160 1.800
2.700 2.250
0.114 0.083
0.229 0.167
0.457 0.333
0.914 0.667
1.371 1.000
1.829 1.333
2.286 1.667
0.034 0.031
0.067 0.062
0.135 0.124
0.269 0.247
0.404 0.371
0.538 0.494
0.673 0.618
750/760
Feeder Management Relay
(EQ 5.3)
8.0 9.0 10.0
0.165 0.156 0.149
0.330 0.312 0.297
0.659 0.623 0.594
1.319 1.247 1.188
1.978 1.870 1.782
2.637 2.493 2.376
3.297 3.116 2.971
0.096 0.084 0.075
0.193 0.169 0.150
0.386 0.338 0.300
0.771 0.675 0.600
1.157 1.013 0.900
1.543 1.350 1.200
1.929 1.688 1.500
0.063 0.050 0.040
0.127 0.100 0.081
0.254 0.200 0.162
0.508 0.400 0.323
0.762 0.600 0.485
1.016 0.800 0.646
1.270 1.000 0.808
0.029 0.027 0.026
0.058 0.054 0.052
0.115 0.109 0.104
0.231 0.218 0.207
0.346 0.327 0.311
0.461 0.435 0.415
0.576 0.544 0.518
5–35