AS 3007.2-2004

1 - AS 3007.2-2004 ELECTRICAL INSTALLATIONS-SURFACE MINES AND ASSOCIATED PROCESSING PLANT - GENERAL PROTECTION REQUIREMENTS
4 - PREFACE
5 - CONTENTS
6 - SECTION 1 SCOPE AND REFERENCED DOCUMENTS
6 - 1.1 SCOPE
6 - 1.2 REFERENCED DOCUMENTS
7 - SECTION 2 PROTECTION AGAINST DIRECT CONTACT
7 - 2.1 INTRODUCTION
7 - 2.2 GENERAL REQUIREMENTS
7 - 2.2.1 General
7 - 2.2.2 Exceptions to the general requirements
7 - 2.3 COMPLETE PROTECTION BY MEANS OF BARRIERS OR ENCLOSURES
7 - 2.3.1 General
8 - 2.3.2 Protection from live parts
8 - 2.3.3 Strength and stability of barriers and enclosures
9 - 2.3.4 Access to installation
10 - 2.4 COMPLETE PROTECTION BY INSULATION OF LIVE PARTS
10 - 2.4.1 General
10 - 2.4.2 Degree of insulation
10 - 2.4.3 Type of insulation
10 - 2.5 PARTIAL PROTECTION BY PLACING LIVE PARTS OUT OF REACH
10 - 2.6 PARTIAL PROTECTION BY THE PROVISION OF OBSTACLES
11 - 2.7 MINIMUM DISTANCES TO BE OBSERVED IN OPERATING AND MAINTENANCE GANGWAYS FOR INDOOR INSTALLATIONS
11 - 2.7.1 General
11 - 2.7.2 Minimum distances
11 - 2.7.3 Minimum width
11 - 2.7.4 Access
11 - 2.8 MINIMUM CLEARANCES FOR OUTDOOR INSTALLATIONS
11 - 2.8.1 Application
12 - 2.8.2 Minimum clearances to boundary fences
12 - 2.8.3 Minimum clearances from accessible areas
12 - 2.8.4 Minimum clearances to barriers
18 - SECTION 3 PROTECTION AGAINST INDIRECT CONTACT-A.C.
18 - 3.1 INTRODUCTION
18 - 3.2 GENERAL
18 - 3.2.1 Use of protective conductors
18 - 3.2.2 Automatic disconnection of supply
19 - 3.2.3 Characteristics of protection
19 - 3.2.4 Protective measures other than use of protective conductors
20 - 3.2.5 Distinction of supply to fixed and portable or mobile apparatus
20 - 3.2.6 Disconnection time for systems above 1000 V
20 - 3.2.7 Coordination of protection
20 - 3.2.8 Exemption from use of protective conductors
20 - 3.3 TN, TT AND IT SYSTEMS DESCRIPTION
20 - 3.3.1 General
21 - 3.3.2 Description of the systems
21 - 3.4 PROTECTIVE MEASURES FOR TN SYSTEMS
21 - 3.4.1 General
21 - 3.4.2 Bonding of exposed conductive parts
26 - 3.4.3 Disconnection following fault
26 - 3.4.4 Single conductor as combined protective and neutral conductor
27 - 3.4.5 Interruption of combined protective and neutral conductor
27 - 3.4.6 Separation of protective conductor from a combined protective and neutral conductor
27 - 3.4.7 Conductor identification
27 - 3.4.8 Protective devices
27 - 3.4.9 Residual-current-operated protective devices
27 - 3.4.10 Voltage balance
28 - 3.5 PROTECTIVE MEASURES FOR TT SYSTEMS
28 - 3.5.1 General
28 - 3.5.2 Neutral conductor insulation and installation
28 - 3.5.3 Bonding of exposed conductive parts
28 - 3.5.4 Conditions to be fulfilled following a fault
29 - 3.5.5 Protective devices
29 - 3.6 PROTECTIVE MEASURES FOR IT SYSTEMS
29 - 3.6.1 General
29 - 3.6.2 Isolation or earthing of the power system earthable point
29 - 3.6.3 Neutral conductor insulation and installation
29 - 3.6.4 Bonding of exposed conductive parts
29 - 3.6.5 Operation of the protective devices under fault condition
30 - 3.6.6 Protective devices
30 - 3.7 REQUIREMENTS FOR EARTH FAULT CURRENT LIMITATION DEVICES
30 - 3.7.1 General
30 - 3.7.2 Neutral earthing reactors and arc suppression coils
31 - 3.7.3 Three-phase earth fault current limiting neutral displacement reactor (zero sequence reactor)
31 - 3.8 EARTHING ARRANGEMENTS AND PROTECTIVE CONDUCTORS
31 - 3.8.1 General requirements
33 - 3.8.2 Earth electrodes.
34 - 3.8.3 Earthing conductors
35 - 3.8.4 Main earthing terminals or bars
35 - 3.8.5 Protective conductors
38 - 3.8.6 Earthing arrangements for protective purposes
38 - 3.8.7 Equipotential bonding
40 - SECTION 4 PROTECTION AGAINST OVERCURRENT
40 - 4.1 INTRODUCTION
40 - 4.2 GENERAL RULE
40 - 4.3 NATURE OF PROTECTIVE DEVICES
40 - 4.3.1 General
40 - 4.3.2 Devices ensuring protection against both overload current and short-circuit current
40 - 4.3.3 Devices ensuring protection against overload current only
40 - 4.3.4 Devices ensuring protection against short-circuit current only
41 - 4.4 AUTOMATIC INTERRUPTION-PROTECTION AGAINST OVERCURRENT DUE TO OVERLOAD
41 - 4.4.1 Conditions of application
41 - 4.4.2 Rating of protective devices and conductors
42 - 4.4.3 Arrangement of the overload protective device
42 - 4.5 AUTOMATIC INTERRUPTION-PROTECTION AGAINST SHORT CIRCUITS
42 - 4.5.1 Conditions of application
42 - 4.5.2 Determination of prospective short-circuit currents
43 - 4.5.3 Operating requirements for short-circuit protection
44 - 4.5.4 Arrangements of devices for short-circuit protection only
44 - 4.6 COORDINATION OF OVERLOAD AND SHORT-CIRCUIT PROTECTION
44 - 4.6.1 Protection afforded by one device
45 - 4.6.2 Protection afforded by separate devices
45 - 4.7 LIMITATION OF OVERCURRENT BY CHARACTERISTICS OF SUPPLY OR LOAD
45 - 4.7.1 Limitation by nature of the load
45 - 4.7.2 Limitation by nature of the source
46 - SECTION 5 SELECTION OF PROTECTIVE DEVICES AND PROTECTION SYSTEMS
46 - 5.1 INTRODUCTION
46 - 5.2 BASIC REQUIREMENTS
46 - 5.2.1 Fuses
46 - 5.2.2 Operating characteristics
46 - 5.3 SELECTION PROCEDURE
46 - 5.3.1 Selection of protection systems
46 - 5.3.2 Selection of devices for protection against short circuits
47 - 5.3.3 Selection of devices for protection against overload
47 - 5.3.4 Selection against indirect contact
47 - 5.4 DISCRIMINATION BETWEEN PROTECTIVE DEVICES
50 - APPENDIX A - SELECTION OF FACTOR k FOR CALCULATING THE MINIMUM CROSS-SECTIONAL AREA OF PROTECTIVE CONDUCTORS...
50 - A1 PROCEDURE FOR SELECTING k VALUES
50 - A2 SUGGESTED INITIAL TEMPERATURES
51 - A3 SUGGESTED FINAL TEMPERATURES
53 - APPENDIX B - DESCRIPTION OF CERTAIN TYPES OF PROTECTIVE DEVICES AND THEIR USES
53 - B1 MEASURING TRANSFORMERS
53 - B2 RESIDUAL-CURRENT-OPERATED PROTECTIVE DEVICES
53 - B3 RESIDUAL-VOLTAGE-OPERATED PROTECTIVE DEVICES
53 - B4 FAULT-VOLTAGE-OPERATED PROTECTIVE DEVICES
53 - B5 COMBINED RESIDUAL CURRENT/VOLTAGE OPERATED PROTECTIVE DEVICES
54 - B6 INSULATION MONITORING DEVICES
54 - B7 DISTANCE RELAYS
54 - B8 DIFFERENTIAL PROTECTION
54 - B9 OVERCURRENT-OPERATED PROTECTIVE DEVICES

Provides measures which are required for protection against electric shock in normal service from direct contact with live parts, for protection against electric shock from parts which may become live in the case of a fault, and for protection against the effects of overcurrent and fault current resulting from overload or short-circuit conditions. Includes requirements for the selection of protective devices and protection systems.

This Standard prescribes general protection requirements for electrical installations within the scope of AS 3007.1. It outlines the measures which are required for protection against electric shock in normal service from direct contact with live parts; for protection against electric shock from parts which may become live in the event of a fault (indirect contact); and for protection against the effects of overcurrent resulting from overload or short-circuit conditions.

First published as AS 3007.2-1982.
Second edition 1987.
Third edition 2004.