5-32
G650 Generator Protection & Control System
GEK-113285A
5.4 PROTECTION ELEMENTS
5 SETTINGS
5
5.4.2.2 IEC CURVES
This family of curves follows the European standard IEC 255-4, and the British standard BF142 for IEC Curves A, B and C,
IEC Long-Time Inverse and IEC Short-Time Inverse. The formulas that define these curves are as follows:
Where:
t = Operation time in seconds
Dial = multiplying factor
I = Input current
Itap = Current pickup value
K, E = constants defined by the standard
T
RESET
= reset time in seconds (assuming 100% of power capacity and that the reset is activated)
t
r
= characteristic constant.
Table 5–31: CONSTANTS FOR IEC CURVES
IEC CURVE SHAPE
NAME
K
E
tr
IEC Curve A
IEC Curve A
0.140
0.020
9.7
IEC Curve B
IEC Curve B
13.500
1.000
43.2
IEC Curve C
IEC Curve C
80.000
2.000
58.2
IEC Long-Time Inverse
IEC Long-Time Inv
120.000
1.000
120.0
IEC Short-Time Inverse
IEC Short-Time Inv
0.050
0.040
0.5
Summary of Contents for Multilin G650
Page 9: ...8 G650 Generator Protection Control System GEK 113285A TABLE OF CONTENTS ...
Page 426: ...GEK 113285A G650 Generator Protection Control System A 31 APPENDIX A A 1 LOGIC OPERANDS A ...
Page 427: ...A 32 G650 Generator Protection Control System GEK 113285A A 1 LOGIC OPERANDS APPENDIXA A ...
Page 587: ...C 22 G650 Generator Protection Control System GEK 113285A C 8 ANALOG INPUTS APPENDIXC C ...
Page 639: ...G 2 G650 Generator Protection Control System GEK 113285A G 1 GE MULTILIN WARRANTY APPENDIXG G ...