GE D90 Plus Instruction Manual page 241

CHAPTER 7: PROTECTION
2
I t curves
FlexCurves™
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
2
The I t curves are derived as follows.
The terms in the above equations are defined as follows.
• T represents the operate time in seconds.
operate
• TDM represents the multiplier setting.
• I represents the input current.
• I represents the pickup current setting value.
pickup
• T represents reset time in seconds, assuming the energy capacity is 100% and the
reset
reset mode is timed.
2
Table 12: I t curve trip times (in seconds)
Multiplier Current (I / I
pickup
(TDM)
1.5 2.0
0.01 0.44 0.25
0.10 4.44 2.50
1.00 44.44 25.00
10.00 444.44 250.00 111.11 62.50
100.00 4444.4 2500.0 1111.1 625.00 400.00 277.78 204.08 156.25 123.46 100.00
600.00 26666. 15000.
7 0
The custom FlexCurve™ shapes are defined as follows.
The terms in the above equations are defined as follows.
• T represents the operate time in seconds.
operate
• TDM represents the multiplier setting.
• I represents the input current.
• I represents the pickup current setting value.
pickup
• T represents reset time in seconds, assuming the energy capacity is 100% and the
reset
reset mode is timed.
)
3.0 4.0 5.0 6.0
0.11 0.06 0.04 0.03
1.11 0.63 0.40 0.28
11.11 6.25 4.00 2.78
40.00 27.78
6666.7 3750.0 2400.0 1666.7 1224.5 937.50 740.74 600.00
GROUPED PROTECTION ELEMENTS
7.0 8.0 9.0 10.0
0.02 0.02 0.01 0.01
0.20 0.16 0.12 0.10
2.04 1.56 1.23 1.00
20.41 15.63 12.35 10.00
Eq. 16
Eq. 17
Eq. 18
Eq. 19
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