4–94
M‑3425A Instruction Book
PROCESSOR
PROTECTION RELAY
M-3425A
Squarewave
Generator
Signal
Measurement and
Processing
Field Ground
Detection
37
35
36
Relay Ground Stud
Coupling
Network
M-3921
TB5
TB4
TB1
V
f
Shield
TB3
TB2
TB1
V
out
Rear Terminal
Block Pin No.
Gen.
Rotor
Excitation
System
Rf.Cf
Shaft
Ground
Brush
Brushes
Ground/Generator Frame
Typical Field Ground Protection
TB3
TB2
TB1
Gen.
Rotor
Rf.Cf
Shaft
Ground
Brush
Measurement
Brush
Ground/Generator Frame
Jumper TB2 to TB3 if
only one brush is used
Brushless Generator Application
Detail A
TB3
TB2
TB1
Gen.
Rotor
Excitation
System
Rf.Cf
Water provides
alternate
ground path.
Brushes
Ground/Generator Frame
Francis or Kaplan Turbine-Generator
Application
Detail B
Detail C
Shielded Cable
Belden 3104A or equivalent is
recommended for connection between
M-3425A and M-3921
Figure 4-70 M-3921 Field Ground Coupler
64F Application for Brushless Generators
The 64F Function can be implemented on brushless
generators that employ a "measurement" brush (Detail C)
to verify the integrity of field. In this configuration generally
only one field polarity is available. Therefore, a suitably sized
jumper must be installed from TB2 to TB3 (Coupling Network
box M-2931) and then to the positive or negative field lead.
In some configurations the measurement brush is
continuously applied. In others the measurement brush is
applied periodically. In configurations that automatically lift the
measurement brush, the 64B Function must be blocked by an
input to the relay to prevent an alarm when the measurement
brush is lifted. If the 64B Function is not desired, then the 64B
Function should be disabled.
The 64F Function can not be used on brushless generators
utilizing LED coupling.
64F Application for Hydro Turbine-Generators
The application of the 64F Function requires a ground return
path, either through a shaft ground brush (Detail A) or though
an alternate ground path (i.e. water for some hydro machines.)
Hydro Turbine-Generator unit shafts that extend into the
water with no electrical isolation between the turbine shaft
and the generator shaft can use the water as the alternate
ground path (Detail B). In this application, the water provides
the alternate ground path and a shaft grounding brush is
not required. Francis and Kaplan Turbine Generators usually
meet this application requirement. If the unit can experience a
low water condition, the low water may not provide a reliable
ground return. For this condition, a shaft ground brush may be
required.
A shaft ground brush must be utilized for the 64F Function on
Pelton Hydro Turbine-Generator applications.
Summary of Contents for M-3425A
Page 1: ...Instruction Book M 3425A Generator Protection ...
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Page 63: ...M 3425A Instruction Book 1 6 This Page Left Intentionally Blank ...
Page 95: ...M 3425A Instruction Book 2 32 This Page Left Intentionally Blank ...
Page 97: ...M 3425A Instruction Book 3 2 Figure 3 2 IPScom Main Screen ...
Page 123: ...M 3425A Instruction Book 3 28 Figure 3 30 View Sequence of Events Recorder Screen ...
Page 131: ...M 3425A Instruction Book 3 36 This Page Left Intentionally Blank ...
Page 162: ...4 31 System Setup and Setpoints 4 Figure 4 15 IPScom Relay Setup System Dialog Screen ...
Page 183: ...4 52 M 3425A Instruction Book Figure 4 32 Volts Per Hertz 24 Setpoint Ranges ...
Page 187: ...4 56 M 3425A Instruction Book Figure 4 34 Sync Check 25 Setpoint Ranges ...
Page 202: ...4 71 System Setup and Setpoints 4 Figure 4 50 49 Function Overload Curves ...
Page 203: ...4 72 M 3425A Instruction Book Figure 4 51 Stator Thermal Protection 49 Setpoint Ranges ...
Page 215: ...4 84 M 3425A Instruction Book Figure 4 62 Phase Overvoltage 59 Setpoint Ranges ...
Page 239: ...4 108 M 3425A Instruction Book Figure 4 80 Out of Step 78 Setpoint Ranges ...
Page 242: ...4 111 System Setup and Setpoints 4 Figure 4 82 Frequency 81 Setpoint Ranges ...
Page 261: ...M 3425A Instruction Book 5 6 Figure 5 5 Mounting Dimensions for GE L 2 Cabinet H3 and H4 ...
Page 277: ...M 3425A Instruction Book 5 22 Figure 5 14 M 3425A Circuit Board ...
Page 278: ...Installation 5 5 23 Figure 5 15 M 3425A Circuit Board Expanded I O ...
Page 280: ...Installation 5 5 25 Figure 5 17 20 Hz Frequency Generator Housing Panel Surface Mount ...
Page 281: ...M 3425A Instruction Book 5 26 Figure 5 18 20 Hz Frequency Generator Housing Panel Flush Mount ...
Page 282: ...Installation 5 5 27 Figure 5 19 20 Hz Band Pass Filter Housing Panel Surface Mount ...
Page 283: ...M 3425A Instruction Book 5 28 Figure 5 20 20 Hz Band Pass Filter Housing Panel Flush Mount ...
Page 284: ...Installation 5 5 29 Figure 5 21 20 Hz Measuring Current Transformer 400 5 A CT ...
Page 421: ...D 2 M 3425A Instruction Book Figure D 1 Volts Hz 24 Inverse Curve Family 1 Inverse Square ...
Page 422: ...Inverse Time Curves Appendix D D 3 Figure D 2 Volts Hz 24 Inverse Family Curve 2 ...
Page 423: ...D 4 M 3425A Instruction Book Figure D 3 Volts Hz 24IT Inverse Curve Family 3 ...
Page 424: ...Inverse Time Curves Appendix D D 5 Figure D 4 Volts Hz 24IT Inverse Curve Family 4 ...
Page 427: ...D 8 M 3425A Instruction Book Figure D 5 BECO Definite Time Overcurrent Curve ...
Page 428: ...Inverse Time Curves Appendix D D 9 Figure D 6 BECO Inverse Time Overcurrent Curve ...
Page 429: ...D 10 M 3425A Instruction Book Figure D 7 BECO Very Inverse Time Overcurrent Curve ...
Page 430: ...Inverse Time Curves Appendix D D 11 Figure D 8 BECO Extremely Inverse Time Overcurrent Curve ...
Page 437: ...D 18 M 3425A Instruction Book Figure D 15 IEEE Extremely Inverse Time Overcurrent Curves ...
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