1 - AS/NZS 4853:2000 ELECTRICAL HAZARDS ON METALLIC PIPELINES
4 - PREFACE
5 - CONTENTS
6 - FOREWORD
7 - 1 SCOPE
7 - 2 APPLICATION
7 - 3 REFERENCED DOCUMENTS
7 - 4 DEFINITIONS
7 - 5 ACCEPTABLE VOLTAGE LIMITS
7 - 5.1 General
8 - 5.2 Risk assessment
9 - 5.3 Category A-touch voltage limits for pipelines accessible to the public or unskilled staff
10 - 5.4 Category B-touch voltage limits (up to 1000 V) for pipelines with restricted public access
11 - 5.5 Voltages in excess of Category B
11 - 5.6 Construction and maintenance
11 - 6 LOW FREQUENCY INDUCTION (LFI)
11 - 6.1 General
12 - 6.2 Load current LFI
12 - 6.3 Fault current LFI
12 - 6.4 A.C. traction LFI
13 - 6.5 Mitigation
14 - 7 CAPACITIVE COUPLING
14 - 7.1 General
14 - 7.2 Mitigation
15 - 8 EFFECTS OF LIGHTNING
15 - 8.1 The electrical nature of lightning
15 - 8.2 The electrical properties of coated pipelines
15 - 8.3 The combination of lightning current with the pipeline
16 - 8.4 Lightning mitigation
16 - 9 CONDUCTIVE EFFECT-EARTH POTENTIAL RISE (EPR)
17 - 10 OTHER HAZARDS
17 - 10.1 Open-circuited neutrals
17 - 10.2 D.C. traction systems
17 - 10.2.1 General
17 - 10.2.2 Voltage exposure
18 - 10.3 Storage and handling of pipe lengths
19 - 11 INTERACTION BETWEEN PROTECTIVE EARTHING SYSTEMS ON PIPE-LINES AND CATHODIC PROTECTION SYSTEMS
19 - 12 COMMISSIONING AND MAINTENANCE OF PIPELINE EARTHING SYSTEMS
19 - 12.1 General
19 - 12.2 Initial commissioning
19 - 12.2.1 General
19 - 12.2.2 Physical inspection
20 - 12.2.3 Electrical performance
20 - 12.3 Periodic integrity checks
20 - 12.4 Performance review
21 - APPENDIX A - LIST OF REFERENCED DOCUMENTS
22 - APPENDIX B - DEFINITIONS
22 - B1 DEFINITIONS
22 - B1.1 General
22 - B1.2 Accessible
22 - B1.3 Anode
22 - B1.4 Authorized person
22 - B1.5 Cathodic protection
22 - B1.6 Converter
22 - B1.7 Diameter
22 - B1.8 Drainage bond
22 - B1.9 Earth (noun)
22 - B1.10 Earth (verb)
23 - B1.11 Electrode
23 - B1.12 Electrolyte
23 - B1.13 Equipotential mats
23 - B1.14 Fluid
23 - B1.15 Gas
23 - B1.16 Holiday
23 - B1.17 Impressed current
23 - B1.18 Isolating joint
23 - B1.19 May
23 - B1.20 Polarization cell
23 - B1.21 Shall
23 - B1.22 Should
23 - B1.23 Structure
23 - B1.24 Test point
23 - B1.25 Touch voltage
24 - APPENDIX C - LOAD CURRENT LFI EXAMPLE CALCULATION
24 - C1 GENERAL
24 - C2 LFI CALCULATION-NO OVERHEAD EARTHWIRES
25 - C3 LFI CALCULATION-WITH OVERHEAD EARTHWIRES
27 - APPENDIX D - FAULT CURRENT LFI EXAMPLE CALCULATION
27 - D1 GENERAL
27 - D2 CALCULATIONS USING p = 100 ohm metres
31 - D3 MUTUAL IMPEDANCE WHEN p VARIES FROM 100 OHM METRES
31 - D4 MAXIMUM TOTAL COUPLING
33 - D5 PARAMETERS REQUIRED TO ASSESS POSSIBLE HAZARDS
33 - D5.1 High voltage power line
34 - D5.2 Metallic pipelines
36 - APPENDIX E - EFFECTS OF A.C. TRACTION SYSTEM ON A NEARBY PIPELINE
36 - E1 TYPES OF A.C. TRACTION SYSTEM
36 - E2 ASSESSMENT OF THE INDUCTION LEVEL INTO ADJACENT PIPELINE
36 - E2.1 General
37 - E2.2 Simple 25kV system with overhead earth wire
38 - E2.3 (25kV) booster transformer system (BT)
40 - E2.4 (25kV – 0 – 25kV) auto-transformer system (AT)
41 - APPENDIX F - PIPELINE LOOP IMPEDANCE
41 - F1 INTRODUCTION
43 - F2 DETERMINATION OF EARTH ELECTRODE RESISTANCE
44 - F3 OTHER OPTIONS
46 - F4 ALTERNATIVE METHOD TO DERIVE LFI FAULT VOLTAGE
47 - APPENDIX G - SAMPLE CALCULATION OF INTERCEPTED CAPACITIVE CURRENT
47 - G1 INTRODUCTION
47 - G2 GENERAL APPROXIMATION
47 - G3 SINGLE PIPE LENGTH
49 - G4 SUMMARY
50 - APPENDIX H - EPR NEAR A HIGH VOLTAGE INSTALLATION
50 - H1 INTRODUCTION
50 - H2 DISTRIBUTION OF FAULT CURRENTS
51 - H3 CALCULATION OF RESISTANCE OF EARTH SYSTEM
51 - H3.1 General
51 - H3.2 Primary electrodes
52 - H4 DETERMINING SURFACE VOLTAGE CONTOURS
52 - H4.1 General
52 - H4.2 Surface voltage gradients
54 - H4.3 Limits for the application of simplified calculations
57 - H5 EXAMPLE-EARTH POTENTIAL RISE SURROUNDING A 275 KV TRANSMISSION TOWER
57 - H5.1 Parameters
57 - H5.2 Resistance of tower footing
57 - H5.3 Earth fault current
57 - H5.4 Earth potential rise
58 - H5.5 Surface voltage contours
58 - H6 MITIGATION
61 - APPENDIX I - MECHANICAL HANDLING OF PIPE LENGTHS
61 - I1 MECHANICAL HANDLING EQUIPMENT
61 - I2 HANDLING WELL-COATED PIPE IN THE VICINITY OF HIGH VOLTAGE POWER LINES
61 - I3 HANDLING LONG LENGTHS OF PIPE STRINGS
62 - I4 STORAGE OF PIPE BELOW HIGH VOLTAGE POWER LINES
62 - I5 PERSONNEL PROTECTION
62 - I5.1 Protective clothing
62 - I5.2 Protective equipment
62 - I5.3 Measuring tapes
63 - APPENDIX J - INTERACTION OF CATHODIC PROTECTION SYSTEMS WITH PIPELINE PROTECTIVE EARTHING SYSTEMS
63 - J1 GENERAL
63 - J2 LFI PROTECTION
63 - J3 LIGHTNING PROTECTION
64 - J4 CATHODIC PROTECTION
65 - APPENDIX K - BIBLIOGRAPHY