AS/NZS 4853:2000

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

Provides voltage limits and corresponding time constraints acceptable on both underground and above-ground metallic pipelines that may be subject to electrical influences due to the close proximity of high voltage power transmission lines. Guidance on how to calculate the induced voltages and mitigate the hazards is provided. Hazards due to lightning strikes are covered.

This Standard specifies voltage limits and corresponding time constraints acceptable on both underground and above-ground pipelines that may be subject to power system influences. Guidance on the mitigation of lightning flash attachments is also provided.NOTE: The acceptable voltage and time limits are based on the conditions outlined in AS 3859. This Standard describes the mechanisms which create hazardous electrical conditions on such pipelines and provides guidance on how to calculate and mitigate these hazards. This Standard does not cover electrical hazards on electricity power plant associated with the construction of pipelines and their coatings. Such hazards are covered by AS/NZS 3000 and its associated Standards.

First published as AS/NZS 4853:2000.