GE T60 Instruction Manual page 486

GROUPED ELEMENTS
Multiplier Current ( I / I
(TDM)
1.5
10.0 11.552
IAC Short Inverse
0.5 0.072
1.0 0.143
2.0 0.286
4.0 0.573
6.0 0.859
8.0 1.145
10.0 1.431
2
I t curves
2
The I t curves are derived as follows:
where
T = Operate time (in seconds)
TDM = Multiplier setting
5
I = Input current
I = Pickup Current setting
pickup
T = reset time in seconds (assuming energy capacity is 100% and RESET is "Timed")
RESET
2
Table 5-38: I t curve trip times
Multiplier
(TDM)
0.01
0.10
1.00
10.00
100.00
600.00
FlexCurves
FlexCurves are described in the FlexCurves section later in this chapter. The curve shapes for the FlexCurves are derived
from the formulae:
where
5-268
)
pickup
2.0 3.0 4.0
7.494 5.320 4.426
0.047 0.035 0.031
0.095 0.070 0.061
0.190 0.140 0.123
0.379 0.279 0.245
0.569 0.419 0.368
0.759 0.559 0.490
0.948 0.699 0.613
Current ( I / I )
pickup
1.5 2.0 3.0
0.44 0.25 0.11
4.44 2.50 1.11
44.44 25.00 11.11
444.44 250.00 111.11
4444.4 2500.0 1111.1
26666.7 15000.0 6666.7
5.0 6.0 7.0
3.922 3.597 3.369
0.028 0.027 0.026
0.057 0.054 0.052
0.114 0.108 0.105
0.228 0.217 0.210
0.341 0.325 0.314
0.455 0.434 0.419
0.569 0.542 0.524
4.0 5.0 6.0
0.06 0.04 0.03
0.63 0.40 0.28
6.25 4.00 2.78
62.50 40.00 27.78
625.00 400.00 277.78
3750.0 2400.0 1666.7
T60 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
8.0 9.0
3.201 3.072
0.026 0.025
0.051 0.050
0.102 0.100
0.204 0.200
0.307 0.301
0.409 0.401
0.511 0.501
7.0 8.0 9.0
0.02 0.02 0.01
0.20 0.16 0.12
2.04 1.56 1.23
20.41 15.63 12.35
204.08 156.25 123.46
1224.5 937.50 740.74
10.0
2.969
0.025
0.049
0.099
0.197
0.296
0.394
0.493
Eq. 5-36
10.0
0.01
0.10
1.00
10.00
100.00
600.00
Eq. 5-37
Eq. 5-38