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HB 102-1997 (CJC 6)
[Current]Provides guidance on the Code CJC 5, Low Frequency Induction (SAA HB101-1997, in sections dealing with the theory of LFI, calculations, determination of best engineering solution, evaluation of contributory and ameliorative factors, examples of calculations, field tests and measurements. Useful data is given in extensive appendices identical with the 1981 Telecom Australia/ESAA publication Application Guide for the Low Frequency Induction Code.
Published: 05/11/1997
Pages: 85
Table of contents
Cited references
Content history
Table of contents
Header
About this publication
PREFACE
1 INTRODUCTION
2 MECHANISM OF LOW FREQUENCY INDUCTION AND CALCULATION OF INDUCED VOLTAGES
3 PROCEDURES FOR MAKING CALCULATIONS AND DETERMINING BEST ENGINEERING SOLUTION
3.1 Calculation Procedure
3.2 Selection of Appropriate Induced Voltage Limit
3.3 Some Factors Considered by the Electricity Utility in Selection of Power Line Categories
4 EVALUATION OF FACTORS FOR CALCULATING INDUCED LONGITUDINAL VOLTAGES
4.1 Earth Fault Currents
4.1.1 Factors Affecting Fault Currents
4.1.2 Calculations of Fault Currents
4.2 Mutual and Self Impedances
4.2.1 Formulas and Nomogram for Calculations
4.2.2 Selection of Earth Resistivity Values
4.3 Shielding Factors
4.3.1 Fundamental Principles
4.3.2 Shielding Factors Relating to Power Lines and Power Cables
4.3.3 Shielding Factors Relating to Telephone Lines
4.3.4 Shielding by Adjacent Conductors
4.3.5 Shielding by Cable Sheaths
4.3.6 Shielding by Magnetic Loading
4.3.7 Shielding by Multiple Telecommunication Cables
4.3.8 Shielding by Environmental Metallic Conductors
4.3.9 Shielding by Earthing Spare Cable Pairs
4.3.10 Latent Shielding
4.4 Overvoltage Protection by Gas-Filled Protectors
4.5 Length of Exposure and Separation
4.5.1 General
4.5.2 Zone of Exposure for which Calculations may not be Required
4.5.3 Examples Where Calculations are Required
4.5.4 Summation of Exposure Sections
4.5.5 General Case
5 EXAMPLE OF CALCULATION
5.1 Typical Case
5.2 Details
5.3 Preparation and Assumptions
5.4 A Method of Making Detailed Calculations
5.4.1 Calculation of Currents for a Fault in the Power Line
5.4.2 Length of Exposure
5.4.3 Separation
5.4.4 Earth Characteristics
5.4.5 Average Mutual Impedance
5.4.6 Calculation of Induced Voltage
5.4.7 Calculation of Shielding Factor
5.4.8 Resultant Induced Voltage
5.4.9 Summary
5.4.10 Calculation of Induced Voltages in the Protected Cable
5.4.11 Conclusion
6 FIELD TESTS AND MEASUREMENTS
6.1 General
6.2 Safety Precautions
6.3 Testing Procedures
6.4 Elements of the Testing Circuit
6.5 Interpretation of Results
6.6 Ancillary Tests
6.6.1 Evaluation of Soil Resistivity
6.6.2 Determining Shielding Factors
6.7 A Practical Example
6.7.1 Details
6.7.2 Objects of the Tests
6.7.3 Lay-out of the Plant
6.7.4 Test Methods
6.7.5 Test Results
6.7.6 Discussion and Summary of Results
6.7.7 Further Action
6.7.8 Conclusions
7 RECORD OF POWER EARTH FAULTS
8 REFERENCES
APPENDIX 1
APPENDIX 2
APPENDIX 3
APPENDIX 4
APPENDIX 5
APPENDIX 6
APPENDIX 7
APPENDIX 8(a)
APPENDIX 8(b)
APPENDIX 8(c)
APPENDIX 8(d)
APPENDIX 8(e)
APPENDIX 8(f)
APPENDIX 8(g)
APPENDIX 9
APPENDIX 10
APPENDIX 11
APPENDIX 12
APPENDIX 13
1 SIGNIFICANCE OF THE PHASE ANGLE BETWEEN THE STANDING VOLTAGE AND THE MEASURED VOLTAGE WHEN THE POWER LINE IS EXCITED
2 DETERMINATION OF INDUCED VOLTAGE DUE TO TEST FAULT CURRENT
Cited references in this standard
Content history
[Current]