GE Multilin
C70 Capacitor Bank Protection and Control System
5-117
5 SETTINGS
5.6 GROUPED ELEMENTS
5
IEEE CURVES:
The IEEE time overcurrent curve shapes conform to industry standards and the IEEE C37.112-1996 curve classifications
for extremely, very, and moderately inverse. The IEEE curves are derived from the formulae:
,
(EQ 5.7)
where:
T
= operate time (in seconds),
TDM
= Multiplier setting,
I
= input current,
I
pickup
= Pickup Current setting
A
,
B
,
p
= constants,
T
RESET
= reset time in seconds (assuming energy capacity is 100% and
RESET
is “Timed”),
t
r
= characteristic constant
Table 5–13: IEEE INVERSE TIME CURVE CONSTANTS
IEEE CURVE SHAPE
A
B
P
T
R
IEEE Extremely Inverse
28.2
0.1217
2.0000
29.1
IEEE Very Inverse
19.61
0.491
2.0000
21.6
IEEE Moderately Inverse
0.0515
0.1140
0.02000
4.85
Table 5–14: IEEE 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
IEEE EXTREMELY INVERSE
0.5
11.341
4.761
1.823
1.001
0.648
0.464
0.355
0.285
0.237
0.203
1.0
22.682
9.522
3.647
2.002
1.297
0.927
0.709
0.569
0.474
0.407
2.0
45.363
19.043
7.293
4.003
2.593
1.855
1.418
1.139
0.948
0.813
4.0
90.727
38.087
14.587
8.007
5.187
3.710
2.837
2.277
1.897
1.626
6.0
136.090
57.130
21.880
12.010
7.780
5.564
4.255
3.416
2.845
2.439
8.0
181.454
76.174
29.174
16.014
10.374
7.419
5.674
4.555
3.794
3.252
10.0
226.817
95.217
36.467
20.017
12.967
9.274
7.092
5.693
4.742
4.065
IEEE VERY INVERSE
0.5
8.090
3.514
1.471
0.899
0.654
0.526
0.450
0.401
0.368
0.345
1.0
16.179
7.028
2.942
1.798
1.308
1.051
0.900
0.802
0.736
0.689
2.0
32.358
14.055
5.885
3.597
2.616
2.103
1.799
1.605
1.472
1.378
4.0
64.716
28.111
11.769
7.193
5.232
4.205
3.598
3.209
2.945
2.756
6.0
97.074
42.166
17.654
10.790
7.849
6.308
5.397
4.814
4.417
4.134
8.0
129.432
56.221
23.538
14.387
10.465
8.410
7.196
6.418
5.889
5.513
10.0
161.790
70.277
29.423
17.983
13.081
10.513
8.995
8.023
7.361
6.891
IEEE MODERATELY INVERSE
0.5
3.220
1.902
1.216
0.973
0.844
0.763
0.706
0.663
0.630
0.603
1.0
6.439
3.803
2.432
1.946
1.688
1.526
1.412
1.327
1.260
1.207
2.0
12.878
7.606
4.864
3.892
3.377
3.051
2.823
2.653
2.521
2.414
4.0
25.756
15.213
9.729
7.783
6.753
6.102
5.647
5.307
5.041
4.827
6.0
38.634
22.819
14.593
11.675
10.130
9.153
8.470
7.960
7.562
7.241
8.0
51.512
30.426
19.458
15.567
13.507
12.204
11.294
10.614
10.083
9.654
10.0
64.390
38.032
24.322
19.458
16.883
15.255
14.117
13.267
12.604
12.068
T
TDM
A
I
I
pickup
----------------
⎝
⎠
⎛
⎞
p
1
–
----------------------------------
B
+
×
=
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 ...