GE Multilin
L90 Line Current Differential System
5-191
5 SETTINGS
5.6 GROUPED ELEMENTS
5
IEC CURVES
For European applications, the relay offers three standard curves defined in IEC 255-4 and British standard BS142. These
are defined as IEC Curve A, IEC Curve B, and IEC Curve C. The formulae for these curves are:
,
(EQ 5.12)
where:
T
= operate time (in seconds),
TDM
= Multiplier setting,
I
= input current,
I
pickup
= Pickup Current setting,
K
,
E
=
constants,
t
r
= characteristic constant, and
T
RESET
= reset time in seconds (assuming energy capacity is 100%
and
RESET
is “Timed”)
Table 5–19: IEC (BS) INVERSE TIME CURVE CONSTANTS
IEC (BS) CURVE SHAPE
K
E
T
R
IEC Curve A (BS142)
0.140
0.020
9.7
IEC Curve B (BS142)
13.500
1.000
43.2
IEC Curve C (BS142)
80.000
2.000
58.2
IEC Short Inverse
0.050
0.040
0.500
Table 5–20: 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
T
TDM
K
I I
pickup
E
1
–
---------------------------------------
=
T
RESET
TDM
t
r
1
I I
pickup
2
–
---------------------------------------
=
Summary of Contents for UR Series L90
Page 652: ...A 16 L90 Line Current Differential System GE Multilin A 1 PARAMETER LISTS APPENDIX A A ...
Page 772: ...B 120 L90 Line Current Differential System GE Multilin B 4 MEMORY MAPPING APPENDIX B B ...
Page 802: ...C 30 L90 Line Current Differential System GE Multilin C 7 LOGICAL NODES APPENDIX C C ...
Page 812: ...D 10 L90 Line Current Differential System GE Multilin D 1 IEC 60870 5 104 APPENDIX D D ...
Page 824: ...E 12 L90 Line Current Differential System GE Multilin E 2 DNP POINT LISTS APPENDIX E E ...
Page 834: ...F 10 L90 Line Current Differential System GE Multilin F 3 WARRANTY APPENDIX F F ...
Page 846: ...xii L90 Line Current Differential System GE Multilin INDEX ...