AS/NZS 3835.2:2006

1-AS/NZS 3835.2:2006 EARTH POTENTIAL RISE-PROTECTION OF TELECOMMUNICATIONS NETWORK USERS, PERSONNEL AND PLANT...
4-PREFACE
5-CONTENTS
7-SECTION 1 SCOPE AND GENERAL
7-1.1 SCOPE
7-1.2 APPLICATION
7-1.3 REFERENCED DOCUMENTS
9-SECTION 2 DEFINITIONS
9-2.1 DEFINITIONS
9-2.1.1 DOG
9-2.1.2 Earth grid voltage rise (EGVR)
10-SECTION 3 EPR AND GENERAL
10-3.1 DESCRIPTION OF EPR
11-3.2 SOME EPR HAZARD SITUATIONS TO CONSIDER
11-3.2.1 Telecommunications cables passing through a hazard zone
12-3.2.2 Telecommunications equipment installed inside a building which may have a hazardous EPR on its power earth
15-3.2.3 Voltage hazard relevant to telecommunications network
15-3.3 CONSIDERATION OF POWER UTILITY CONSTRUCTION PROPOSALS
16-SECTION 4 EPR HAZARD VOLTAGE LIMITS
16-4.1 INTRODUCTION
16-4.2 RISK OF EPR HAZARD
17-4.3 AUSTRALIAN EPR HAZARD VOLTAGE LIMITS
17-4.4 BASIS OF AUSTRALIAN EPR HAZARD VOLTAGE LIMITS
18-4.5 NEW ZEALAND EPR HAZARD VOLTAGE LIMITS
19-4.6 BASIS OF NEW ZEALAND EPR HAZARD VOLTAGE LIMITS
20-SECTION 5 ASSESSMENT OF EPR
20-5.1 EPR ASSESSMENT PROCESS
21-5.2 COMBINED EPR AND LFI EFFECTS
22-5.3 HAZARD CALCULATIONS IN SMALL INSTALLATIONS
22-5.3.1 General
22-5.3.2 EPR calculation
23-5.4 ELECTRODES
23-5.4.1 General
23-5.4.2 Primary electrodes
24-5.5 ESTIMATION OF EARTH FAULT CURRENTS
24-5.6 SURFACE VOLTAGE GRADIENTS
24-5.6.1 Earth resistivity known
25-5.6.2 Uncertainties in earth resistivity
26-5.7 LIMITS FOR APPLYING THE SIMPLIFIED CALCULATIONS
26-5.7.1 General
26-5.7.2 Non-hemispherical earthing systems
27-5.7.3 Multilayer earth resistivity effects
27-5.7.4 Conductors extending the EPR
28-5.8 EPR IN LARGE SUBSTATIONS
28-5.8.1 General
28-5.8.2 EPR calculation
28-5.9 EARTH SYSTEM IMPEDANCE
28-5.9.1 General
29-5.9.2 Aerial conductors
29-5.9.3 Underground cables
30-5.10 DETERMINATION OF PROSPECTIVE FAULT CURRENT (Initial estimate)
30-5.11 COMPUTER ANALYSIS
33-SECTION 6 FIELD TESTS AND MEASUREMENTS
33-6.1 INTRODUCTION
33-6.2 OBJECTIVES OF FIELD TESTS
33-6.3 METHODOLOGY
33-6.4 CURRENT INJECTION TESTS
33-6.4.1 General
34-6.4.2 50 Hz high-current injection test
35-6.4.3 Off-frequency high-current injection test
36-6.4.4 Off-frequency low-current injection test
39-6.5 SELECTION OF THE APPROPRIATE INJECTION METHOD
40-6.6 CURRENT SOURCES
40-6.6.1 Maximum value
40-6.6.2 50 Hz high-current source
41-6.6.3 Off-frequency high-current source
41-6.6.4 Off-frequency low-current source
42-6.7 REMOTE CURRENT ELECTRODE
42-6.7.1 Injection earth electrode
42-6.7.2 Potential measurement reference earth electrode
43-6.8 MEASURING GRID IMPEDANCE
43-6.8.1 Small earthing system
43-6.8.2 Tower or conductive pole earth resistance measurement
44-6.8.3 Large earthing system (fall of potential method)
45-6.9 MEASURING SURFACE VOLTAGE GRADIENTS
49-6.10 INTERFERENCE ELIMINATION
49-6.10.1 50 Hz standing voltage
49-6.10.2 Induced voltages
49-6.10.3 D.C. interference
50-6.10.4 Harmonic interferences
50-6.11 INTERPRETATION OF RESULTS
50-6.11.1 Extrapolation to remote earth
53-6.12 CONSIDERATION IN CONJUNCTION WITH LOW FREQUENCY INDUCTION (LFI)
54-6.13 SAFETY PRECAUTIONS
55-6.14 COORDINATION
55-6.14.1 Purposes of coordination
55-6.14.2 Coordination of tests
55-6.15 SOIL RESISTIVITY
55-6.15.1 General
57-6.16 METHODS OF MEASUREMENT (WENNER AND SCHLUMBERGER ARRAYS)
57-6.16.1 Symmetrical line arrays
58-6.16.2 Advantages of Wenner array
58-6.16.3 Advantages of Schlumberger array
59-6.17 RESISTIVITY MEASUREMENT ANALYSIS
59-6.17.1 Earth resistivity interpretation procedure
60-6.18 INTERPRETATION OF RESISTIVITY MEASUREMENT
61-6.19 SOURCES OF ERRORS
61-6.20 EQUIPMENT AND INSTRUMENTATION
62-6.21 CALIBRATION OF EQUIPMENT
63-SECTION 7 MITIGATION
63-7.1 INTRODUCTION
63-7.2 SCOPE OF MITIGATION
63-7.3 MITIGATION MEASURES APPLIED TO POWER SYSTEM PLANT
63-7.3.1 General
64-7.3.2 Design options for minimizing EPR problems
70-7.4 LIGHTNING PROTECTION AT TELECOMMUNICATIONS USERs PREMISES
71-7.5 MITIGATION MEASURES APPLIED TO TELECOMMUNICATIONS PLANT
71-7.5.1 General
71-7.5.2 Telecommunications isolation equipment
77-7.5.3 Installation of isolation equipment
80-7.5.4 Other mitigation measures that may be applied to telecommunications plant
85-7.5.5 Other services entering or leaving a HV site or EPR hazard zone
85-7.5.6 HV and LV monitoring, metering, and control equipment using telecommunications services
86-APPENDIX A - TYPICAL HAZARD ZONES
86-A1 INTRODUCTION
86-A2 SCOPE
86-A3 TYPICAL EXTENT OF HAZARD ZONES
86-A3.1 For Australia
86-A3.2 For New Zealand
86-A4 GUIDELINES FOR INTERPRETATION OF THE TYPICAL HAZARD ZONE
101-APPENDIX B - EPR DANGER SIGNS-AUSTRALIA ONLY SIGNS FOR HV SITES AND COMMUNICATIONS CABLE PITS/MANHOLES
101-B1 SCOPE
101-B2 GENERAL
104-APPENDIX C - BIBLIOGRAPHY