GE T35 Instruction Manual page 161

5 SETTINGS
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:
T TDM
=
where: T = operate time (in seconds), TDM = Multiplier setting, I = input current, I
A, B, p = constants, T
t = characteristic constant
r
Table 5–12: IEEE INVERSE TIME CURVE CONSTANTS
IEEE CURVE SHAPE
IEEE Extremely Inverse
IEEE Very Inverse
IEEE Moderately Inverse
Table 5–13: IEEE CURVE TRIP TIMES (IN SECONDS)
MULTIPLIER
(TDM)
1.5 2.0
IEEE EXTREMELY INVERSE
0.5 11.341 4.761
1.0 22.682 9.522
2.0 45.363 19.043
4.0 90.727 38.087
6.0 136.090 57.130
8.0 181.454 76.174
10.0 226.817 95.217
IEEE VERY INVERSE
0.5 8.090 3.514
1.0 16.179 7.028
2.0 32.358 14.055
4.0 64.716 28.111
6.0 97.074 42.166
8.0 129.432 56.221
10.0 161.790 70.277
IEEE MODERATELY INVERSE
0.5 3.220 1.902
1.0 6.439 3.803
2.0 12.878 7.606
4.0 25.756 15.213
6.0 38.634 22.819
8.0 51.512 30.426
10.0 64.390 38.032
GE Multilin
A
B
--------------------------------- -
+
p
I
×  
T
,
--------------- -
1
RESET
–
 
I
pickup
= reset time in seconds (assuming energy capacity is 100% and
RESET
A B
28.2 0.1217
19.61 0.491
0.0515 0.1140
CURRENT ( I / I
3.0 4.0
1.823 1.001 0.648
3.647 2.002 1.297
7.293 4.003 2.593
14.587 8.007 5.187
21.880 12.010 7.780
29.174 16.014 10.374
36.467 20.017 12.967
1.471 0.899 0.654
2.942 1.798 1.308
5.885 3.597 2.616
11.769 7.193 5.232
17.654 10.790 7.849
23.538 14.387 10.465
29.423 17.983 13.081
1.216 0.973 0.844
2.432 1.946 1.688
4.864 3.892 3.377
9.729 7.783 6.753
14.593 11.675 10.130
19.458 15.567 13.507
24.322 19.458 16.883
T35 Transformer Management Relay
t
r
--------------------------------- -
×
TDM
I 2
=  
--------------- -
1
–
 
I
pickup
= Pickup Current setting
pickup
P T
R
2.0000 29.1
2.0000 21.6
0.02000 4.85
)
pickup
5.0 6.0 7.0
0.464 0.355
0.927 0.709
1.855 1.418
3.710 2.837
5.564 4.255
7.419 5.674
9.274 7.092
0.526 0.450
1.051 0.900
2.103 1.799
4.205 3.598
6.308 5.397
8.410 7.196
10.513 8.995
0.763 0.706
1.526 1.412
3.051 2.823
6.102 5.647
9.153 8.470
12.204 11.294
15.255 14.117
5.5 GROUPED ELEMENTS
(EQ 5.23)
is "Timed"),
RESET
8.0 9.0 10.0
0.285 0.237 0.203
0.569 0.474 0.407
1.139 0.948 0.813
2.277 1.897 1.626
3.416 2.845 2.439
4.555 3.794 3.252
5.693 4.742 4.065
0.401 0.368 0.345
0.802 0.736 0.689
1.605 1.472 1.378
3.209 2.945 2.756
4.814 4.417 4.134
6.418 5.889 5.513
8.023 7.361 6.891
0.663 0.630 0.603
1.327 1.260 1.207
2.653 2.521 2.414
5.307 5.041 4.827
7.960 7.562 7.241
10.614 10.083 9.654
13.267 12.604 12.068
5-83
5