AS/NZS 3008.1.2:1998

AS/NZS 3008.1.2:1998 ELECTRICAL INSTALLATIONS - SELECTION OF CABLES - CABLE FOR ALTERNATING VOLTAGES UP TO AND INCLUDING 0.6/1 K

PREFACE

CONTENTS

FOREWORD

SECTION 1 SCOPE AND GENERAL

1.1 SCOPE AND APPLICATION

1.1.1 Scope

1.1.2 Application

1.2 ALTERNATIVE SPECIFICATIONS

1.3 REFERENCED AND RELATED DOCUMENTS

1.3.1 Referenced documents

1.3.2 Related documents

1.4 DEFINITIONS

1.4.1 Ambient temperature

1.4.2 Continuous loading

1.4.3 Ladder support

1.4.4 Perforated tray

1.4.5 Route length

SECTION 2 CABLE SELECTION PROCEDURE

2.1 GENERAL

2.2 SELECTION PROCESS

2.3 DETERMINATION OF MINIMUM CABLE SIZE BASED ON CURRENT-CARRYING CAPACITY CONSIDERATIONS

2.4 DETERMINATION OF MINIMUM CABLE SIZE BASED ON VOLTAGE DROP CONSIDERATIONS

2.5 DETERMINATION OF MINIMUM CABLE SIZE BASED ON THE SHORT-CIRCUIT TEMPERATURE CONSIDERATIONS

SECTION 3 CURRENT-CARRYING CAPACITY

3.1 RATINGS

3.1.1 General

3.1.2 Basis

3.2 TYPES OF CONDUCTORS

3.2.1 Conductor material

3.2.2 Insulation material operating temperatures

3.3 TYPES OF CABLE

3.3.1 Sheathed and unsheathed thermoplastic, elastomer and XLPE cables

3.3.2 Flexible cords and cables

3.3.3 Mineral-insulated metal-sheathed (MIMS) cables

3.3.4 Aerial cables

3.3.5 Neutral-screened cables

3.3.6 High temperature elastomer, polymeric or fibrous cables and flexible cords

3.3.7 Other cable types

3.4 INSTALLATION CONDITIONS

3.4.1 General

3.4.2 Cables installed in air

3.4.3 Cables installed in thermal insulation

3.4.4 Cables buried direct in the ground

3.4.5 Cables installed in underground wiring enclosures

3.4.6 Variation of installation conditions along cable run

3.5 EXTERNAL INFLUENCES ON CABLES

3.5.1 Application of rating factors

3.5.2 Effect of grouping of cables

3.5.3 Effect of ambient temperature

3.5.4 Effect of depth of laying

3.5.5 Effect of thermal resistivity of soil

3.5.6 Effect of varying loads

3.5.7 Effect of thermal insulation

3.5.8 Effect of direct sunlight

SECTION 4 VOLTAGE DROP

4.1 GENERAL

4.2 DETERMINATION OF VOLTAGE DROP FROM MILLIVOLTS PER AMPERE METRE

4.3 DETERMINATION OF VOLTAGE DROP FROM CIRCUIT IMPEDANCE

4.3.1 General

4.3.2 Single-phase, two-wire supply system

4.3.3 Three-phase, three-wire or four-wire supply system

4.3.4 Two-phase, three-wire, earthed neutral 120-degree supply system

4.3.5 Single-phase, three-wire, earthed centre-tapped 180-degree supply system

4.4 DETERMINATION OF VOLTAGE DROP FROM CABLE OPERATING TEMPERATURE

4.5 DETERMINATION OF VOLTAGE DROP FROM LOAD POWER FACTOR

4.6 DETERMINATION OF VOLTAGE DROP IN UNBALANCED MULTIPHASE CIRCUITS

SECTION 5 SHORT-CIRCUIT PERFORMANCE

5.1 GENERAL

5.2 FACTORS GOVERNING THE APPLICATION OF THE TEMPERATURE LIMITS

5.3 CALCULATION OF PERMISSIBLE SHORT-CIRCUIT CURRENTS

5.4 INFLUENCE OF METHOD OF INSTALLATION

5.5 MAXIMUM PERMISSIBLE SHORT-CIRCUIT TEMPERATURES

5.5.1 General

5.5.2 Insulating materials

5.5.3 Outer sheath and bedding materials

5.5.4 Conductor and metallic sheath materials and components

APPENDIX A - EXAMPLES OF THE SELECTION OF CABLES TO SATISFY CURRENT-CARRYING CAPACITY, VOLTAGE DROP AND SHORT-CIRCUIT PERFORMANC

A1 EXAMPLE 1

A1.1 Problem

A1.2 Solution

A1.3 Comparison of different methods

A2 EXAMPLE 2

A2.1 Problem

A2.2 Solution

A3 EXAMPLE 3

A3.1 Problem

A3.2 Solution

A4 EXAMPLE 4

A4.1 Problem

A4.2 Solution

A5 EXAMPLE 5

A5.1 Problem

A5.2 Solution

A6 EXAMPLE 6

A6.1 Problem

A6.2 Solution

A7 EXAMPLE 7

A7.1 Problem

A7.2 Solution

A8 EXAMPLE 8

A8.1 Problem

A8.2 Solution

APPENDIX B - RECOMMENDED CIRCUIT CONFIGURATIONS FOR THE INSTALLATION OF SINGLE-CORE CABLES IN PARALLEL