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6–41
Testing – 6
Once the capacitance value and the operating frequency have been determined, the actual insulation
resistance can be verified by installing a variable resistor (5 to 100 KW) and discrete capacitor to the coupler
module (M-3921).
M-3425
PROCESSOR
Field Ground
Detection
Squarewave
Generator
Signal
Measurement
and
Processing
V
out
Vf
Rear Terminal
Block Pin No.
Coupling
Network
M-3921
DC Supply
37
35
36
5
4
1
3
2
1
Decade Box or Discrete Resistor
to simulate Fault Resistance
Discrete Capacitor to
simulate Field Winding
Capacitance
Cf*
Rf
60 to 100 V dc source - simulates
Exciter Supply Voltage
* If the rotor is NOT connected, the value of Cf should approximate
the rotor capacitance. If the rotor is connected Cf is NOT required.
Figure 6-14
Field Ground Coupler
Summary of Contents for M-3425
Page 1: ...Instruction Book M 3425 Generator Protection ...
Page 14: ... 13 M 3425 Generator Protection Relay Figure 1 External Connections ...
Page 33: ...x M 3425 Instruction Book This Page Left Intentionally Blank ...
Page 89: ...M 3425 Instruction Book 2 52 This Page Left Intentionally Blank ...
Page 125: ...1 3 A B C M 3425 Instruction Book 4 26 This Page Left Intentionally Blank ...
Page 187: ...M 3425 Instruction Book 6 50 This Page Left Intentionally Blank ...
Page 207: ...M 3425 Instruction Book C 4 This Page Left Intentionally Blank ...
Page 209: ...D 2 M 3425 Instruction Book Figure D 1 Volts Hz 24 Inverse Curve Family 1 Inverse Square ...
Page 210: ...Inverse Time Curves Appendix D D 3 Figure D 2 Volts Hz 24 Inverse Family Curve 2 ...
Page 211: ...D 4 M 3425 Instruction Book Figure D 3 Volts Hz 24IT Inverse Curve Family 3 ...
Page 212: ...Inverse Time Curves Appendix D D 5 Figure D 4 Volts Hz 24IT Inverse Curve Family 4 ...
Page 215: ...D 8 M 3425 Instruction Book Figure D 5 Definite Time Overcurrent Curve ...
Page 216: ...Inverse Time Curves Appendix D D 9 Figure D 6 Inverse Time Overcurrent Curve ...
Page 217: ...D 10 M 3425 Instruction Book Figure D 7 Very Inverse Time Overcurrent Curve ...
Page 218: ...Inverse Time Curves Appendix D D 11 Figure D 8 Extremely Inverse Time Overcurrent Curve ...
Page 223: ...D 16 M 3425 Instruction Book This Page Intentionally Left Blank ...