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S4 Elements
745
Transformer Management Relay
Se
tpoints
http://www.GEindustrial.com/multilin
5–52
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:
(EQ 5.8)
where:
T
= trip time (seconds),
M
= multiplier setpoint,
I
= input current,
I
pickup
= pickup current setpoint,
K
, E = constants.
Table 5–6: IEC (BS) Inverse Time Curve Constants
IEC (BS) Curve Shape
K
E
IEC Curve A (BS142)
0.140
0.020
IEC Curve B (BS142)
13.500
1.000
IEC Curve C (BS142)
80.000
2.000
IEC Short Inverse
0.050
0.040
T
M
K
I I
pu
⁄
(
)
E
1
–
---------------------------------
×
=
Table 5–7: IEC Curve Trip Times (in seconds)
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 Time
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
Summary of Contents for Multilin 745
Page 2: ......