AS 2381.1-1991

1 - AS 2381.1-1991 ELECTRICAL EQUIPMENT FOR EXPLOSIVE ATMOSPHERES-SELECTION, INSTALLATION AND MAINTENANCE - GENERAL REQUIREMENTS
4 - PREFACE
5 - CONTENTS
7 - FOREWORD
8 - SECTION 1 GENERAL
8 - 1.1 SCOPE
8 - 1.2 APPLICATION
8 - 1.3 REFERENCED DOCUMENTS
8 - 1.4 DEFINITIONS.
8 - 1.4.1 Approved, approval
8 - 1.4.2 Area, hazardous
8 - 1.4.3 Area, non-hazardous
8 - 1.4.4 Authority, authority having jurisdiction
8 - 1.4.5 Chemical compatibility
9 - 1.4.6 Class I areas
9 - 1.4.7 Class II areas
9 - 1.4.8 Cloud ignition temperature
9 - 1.4.9 Combustible dust
9 - 1.4.10 Degree of protection of enclosures
9 - 1.4.11 Ex component
9 - 1.4.12 Explosive atmosphere
9 - 1.4.13 Explosion-protection
9 - 1.4.14 Flammable gas or vapour
9 - 1.4.15 Flammable liquid
9 - 1.4.16 Flammable material
9 - 1.4.17 Flashpoint
9 - 1.4.18 Hazard
9 - 1.4.19 Ignition source
9 - 1.4.20 Ignition temperature (of an explosive gas atmosphere)
9 - 1.4.21 Layer ignition temperature (of dusts)
10 - 1.4.22 Lower explosive limit (LEL)
10 - 1.4.23 Maximum surface temperature
10 - 1.4.24 Source of release
10 - 1.4.25 Temperature classification
10 - 1.4.26 Unprotected surface
10 - 1.4.27 Upper explosive limit (UEL)
10 - 1.5 STATUTORY REGULATIONS
10 - 1.6 CLASSIFICATION OF HAZARDOUS AREAS
10 - 1.7 OTHER CONSIDERATIONS
10 - 1.7.1 Toxic risks
10 - 1.7.2 Non-electrical ignition sources
10 - 1.7.3 Static electricity
10 - 1.7.4 Lightning
10 - 1.7.5 Electromagnetic radiation
10 - 1.7.6 Cathodic protection
10 - 1.7.7 Personal equipment
11 - 1.8 PREVENTION OF EXPLOSION
11 - 1.8.1 General
11 - 1.8.2 Suppression or avoidance
11 - 1.8.3 Explosion-protected electrical equipment
11 - 1.8.4 Conditions of control
11 - 1.9 COMPLIANCE WITH OTHER PARTS OF THIS STANDARD
12 - SECTION 2 SELECTION OF ELECTRICAL EQUIPMENT
12 - 2.1 SCOPE OF SECTION
12 - 2.2 CLASS I HAZARDOUS AREAS
12 - 2.2.1 Information required
12 - 2.2.2 Selection with respect to area classification
12 - 2.2.3 Selection with respect to temperature classification
14 - 2.2.4 Selection with respect to equipment grouping
14 - 2.3 CLASS II HAZARDOUS AREAS
14 - 2.3.1 Information required
14 - 2.3.2 Selection with respect to ambient temperature limitation
14 - 2.3.3 Selection with respect to area classification
14 - 2.3.4 Selection with respect to temperature classification
14 - 2.3.5 Types of protection
15 - SECTION 3 INSTALLATION
15 - 3.1 SCOPE OF SECTION
15 - 3.2 APPLICATION
15 - 3.3 ACCESS FOR INSPECTION
15 - 3.4 ELECTRICAL RATING
15 - 3.5 PROTECTION FROM MECHANICAL AND ENVIRONMENTAL INJURY
15 - 3.6 SPECIAL INSTALLATION TECHNIQUES
15 - 3.6.1 General
15 - 3.6.2 Wiring entry
15 - 3.6.3 Unused cable entries
15 - 3.6.4 Glands and seals
15 - 3.7 EARTHING
15 - 3.8 EQUIPOTENTIAL BONDING
16 - 3.9 ELECTRICAL PROTECTION
16 - 3.9.1 General
16 - 3.9.2 Earth-fault protection
16 - 3.9.3 Installations not exceeding 650V
17 - 3.9.4 Location of protection and control equipment
17 - 3.10 ENCLOSURE AND TERMINATION OF EARTHING CONDUCTORS
17 - 3.11 ISOLATION
17 - 3.12 EMERGENCY SUPPLIES
17 - 3.13 WIRING SYSTEMS-GENERAL REQUIREMENTS
17 - 3.13.1 Specific methods not permitted
17 - 3.13.2 Permitted types
17 - 3.13.3 Telecommunications circuits
17 - 3.13.4 Consideration of environment
18 - 3.13.5 Electrical continuity of metallic enclosures, conduits, sheaths and armour
18 - 3.13.6 Circuits traversing a hazardous area
18 - 3.13.7 Segregation of wiring systems
18 - 3.13.8 Flexible connections to fixed equipment
18 - 3.13.9 Surge protection of circuits supplied from overhead lines
18 - 3.14 EQUIPMENT - GENERAL REQUIREMENTS
18 - 3.14.1 Specific equipment not permitted in hazardous areas
19 - 3.14.2 Permitted equipment
19 - 3.14.3 Equipment above hazardous areas
19 - 3.15 INSTALLATIONS IN ZONE O AREAS
19 - 3.15.1 Cable systems
19 - 3.15.2 Conduit systems
19 - 3.16 INSTALLATIONS IN ZONE 1 AREAS
19 - 3.16.1 Flexible connections
20 - 3.16.2 Conduit systems
21 - 3.16.3 Fixed cable systems
21 - 3.16.4 Plugs and socket-outlets
22 - 3.16.5 Pendant luminaires
22 - 3.16.6 Ovens
22 - 3.16.7 Heating cables
22 - 3.16.8 Canned pumps and process connections
22 - 3.16.9 Motors
22 - 3.17 INSTALLATIONS IN ZONE 2 AREAS
22 - 3.17.1 Wiring systems
22 - 3.17.2 Switchgear and controlgear
22 - 3.17.3 Combined switch and socket-outlets
22 - 3.17.4 Pendant luminaires
22 - 3.17.5 Canned pumps and process connections
23 - 3.18 INSTALLATIONS IN CLASS II AREAS
23 - 3.18.1 Wiring systems
23 - 3.18.2 Dielectrics having a flashpoint exceeding 250°C
23 - 3.18.3 Luminaires
23 - 3.18.4 Pendant luminaires
24 - SECTION 4 INSPECTION AND TESTING, INCLUDING COMMISSIONING
24 - 4.1 GENERAL
24 - 4.2 DOCUMENTATION
24 - 4.3 QUALIFICATIONS OF PERSONNEL
24 - 4.4 INSPECTION
24 - 4.5 TESTING
24 - 4.5.1 General
24 - 4.5.2 Pre-commissioning tests
24 - 4.5.3 Procedure for testing compliance of circuit with Clause 3.9.3(b)
25 - 4.6 PRECAUTIONS
25 - 4.6.1 Equipment to be rendered dead
25 - 4.6.2 Check on explosive atmosphere
25 - 4.6.3 Igniting agencies
27 - SECTION 5 MAINTENANCE
27 - 5.1 SCOPE OF SECTION
27 - 5.2 GENERAL
27 - 5.3 FLEXIBLE CABLES AND CORDS
27 - 5.4 CLEANLINESS
27 - 5.5 ALTERATIONS
27 - 5.6 WELDING
27 - 5.7 WITHDRAWAL FROM SERVICE
27 - 5.8 FASTENINGS AND TOOLS
27 - 5.9 WEATHER PROTECTION
27 - 5.10 ANTICONDENSATION DEVICES
27 - 5.11 VIBRATION EFFECTS
27 - 5.12 NON-CONDUCTIVE ELECTRICAL EQUIPMENT
28 - APPENDIX A - PROPERTIES OF FLAMMABLE LIQUIDS, VAPOURS AND GASES
28 - A1 SCOPE
28 - A2 FLASHPOINT
28 - A2.1 General
28 - A2.2 Materials having high flashpoints
28 - A2.3 Classification of flashpoints
28 - A3 IGNITION TEMPERATURE
28 - A3.1 General
28 - A3.2 Use of ignition temperature
28 - A4 EXPLOSIVE (FLAMMABLE) LIMITS
29 - A5 EXPLOSIVE (FLAMMABILITY) RANGE
29 - A6 VAPOUR DENSITY
29 - A6.1 General
29 - A6.2 Effects of temperature changes
29 - A7 BOILING POINT
29 - A8 TEMPERATURE CLASSIFICATION
29 - A9 CLASSIFICATION OF GASES AND VAPOURS
29 - A9.1 General
30 - A9.2 Classification according to the Maximum Experimental Safe Gaps (MESG)
30 - A9.3 Classification according to the Minimum Igniting Currents (MIC)
30 - A9.4 Classification according to MESG and MIC
30 - A9.5 Classification according to a similarity of chemical structure
30 - A9.6 Tables of gases
30 - A10 GENERAL CONSIDERATIONS
30 - A10.1 Relation between ignition temperature and maximum surface temperature
31 - A10.2 Mixtures of compounds
31 - A10.3 Mists
31 - A10.4 Impurities
31 - A10.5 Effect of environments having other than normal atmospheric conditions
36 - APPENDIX B - FRICTIONAL SPARKING RISKS WITH LIGHT METALS AND THEIR ALLOYS
36 - B1 GENERAL
36 - B2 RIGIDLY MOUNTED EQUIPMENT
36 - B3 PORTABLE AND TRANSPORTABLE EQUIPMENT
36 - B4 FANS
36 - B5 ALUMINIUM CONDUCTORS
37 - APPENDIX C - CALCULATION OF THE EXPLOSIVE LIMITS FOR A MIXTURE OF GASES
37 - C1 LIMITS FOR SIMPLE MIXTURES
38 - C2 LIMITS FOR COMPLEX INDUSTRIAL GAS MIXTURES
41 - APPENDIX D - MARKING OF EXPLOSION-PROTECTED ELECTRICAL EQUIPMENT
41 - D1 GENERAL
41 - D2 INFORMATION TO BE MARKED
41 - D3 MIXED TYPES OF EXPLOSION-PROTECTION
42 - D4 ORDER OF MARKING
42 - D5 MARKING OF EXCOMPONENTS
42 - D6 MARKING OF SMALL ELECTRICAL EQUIPMENT
42 - D7 METHOD OF MARKING
42 - D7.1 General
42 - D7.2 Adhesive metallic labels
42 - D7.3 Nameplates
42 - D7.4 Other forms of labelling
42 - D8 EXAMPLES OF MARKING
44 - APPENDIX E - LIST OF REFERENCED DOCUMENTS
46 - APPENDIX F - RELATIONSHIP BETWEEN EQUIPMENT GROUPS AND FORMER GAS GROUPS OR CLASSES

Specifies general requirements for the selection, installation and maintenance of electrical equipment for use in areas where flammable materials are generated, processed, handled or stored, and which are therefore potentially hazardous.

Under Revision see DR 98297.
Draft Amendment 3 see DR 98497 CP