5-118
C70 Capacitor Bank Protection and Control System
GE Multilin
5.6 GROUPED ELEMENTS
5 SETTINGS
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 5.8)
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 5–15: 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 5–16: 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 C70
Page 2: ......
Page 10: ...x C70 Capacitor Bank Protection and Control System GE Multilin TABLE OF CONTENTS ...
Page 344: ...5 220 C70 Capacitor Bank Protection and Control System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Page 586: ...D 10 C70 Capacitor Bank Protection and Control System GE Multilin D 1 OVERVIEW APPENDIXD D ...
