Table of Contents

1 -  AS 2380.4-1994 ELECTRICAL EQUIPMENT FOR EXPLOSIVE ATMOSPHERES - EXPLOSION-PROTECTION TECHNIQUES - PRESSURIZED ROOMS OR PRESSU
4 -  PREFACE
5 -  CONTENTS
7 -  SECTION 1 SCOPE AND GENERAL
7 -  1.1 SCOPE
7 -  1.2 REFERENCED DOCUMENTS
8 -  1.3 DEFINITIONS
8 -  1.3.1 Air lock
8 -  1.3.2 Continuous dilution
8 -  1.3.3 Enclosure
8 -  1.3.4 Explosive atmosphere
8 -  1.3.5 Flammable material
8 -  1.3.6 Fresh air
8 -  1.3.7 Hazard
8 -  1.3.8 Ignition-capable equipment
8 -  1.3.9 Internal source of flammable gas or vapour
8 -  1.3.10 Lower explosive limit (LEL)
8 -  1.3.11 Opening
8 -  1.3.12 Pressurization
8 -  1.3.13 Pressurization by circulation of protective gas
8 -  1.3.14 Pressurization with leakage compensation
8 -  1.3.15 Pressurized enclosure
8 -  1.3.16 Protective device
9 -  1.3.17 Protective gas
9 -  1.3.18 Purging
9 -  1.3.19 Room
9 -  1.3.20 Self-revealing fault
9 -  1.3.21 Type of protection ‘p’
9 -  1.4 TEMPERATURE LIMITS
9 -  1.5 GROUPING OF EQUIPMENT
9 -  1.6 PRESSURIZATION PRINCIPLE
11 -  SECTION 2 GENERAL CONSTRUCTIONAL REQUIREMENTS
11 -  2.1 SCOPE OF SECTION
11 -  2.2 ELECTRICAL PERFORMANCE OF EQUIPMENT
11 -  2.3 CONSTRUCTION MATERIALS
11 -  2.4 PROTECTION AGAINST ENVIRONMENT
11 -  2.5 PRESSURIZATION
11 -  2.5.1 Overpressure requirements
11 -  2.5.2 Dual pressurization
11 -  2.6 INLET AND OUTLET APERTURES
11 -  2.7 ALTERNATIVE SOURCES OF PROTECTIVE GAS
12 -  2.8 INTAKE DUCTING
12 -  2.9 ELECTRICAL CONNECTIONS TO ENCLOSURES
12 -  2.10 ENTRY OF ELECTRICAL AND OTHER SERVICES TO ROOMS
12 -  2.11 DOORS AND COVERS
12 -  2.12 POSSIBLE SOURCES OF IGNITION
12 -  2.13 ENCLOSED COMPONENTS
12 -  2.14 PRESSURE OR FLOW ACTIVATED DEVICES
13 -  2.15 SUPPLY OF PROTECTIVE GAS
13 -  2.15.1 Type of gas
13 -  2.15.2 Temperature
13 -  2.16 ROTATING MACHINES
13 -  2.17 PROTECTION REQUIREMENTS
13 -  2.17.1 General
13 -  2.17.2 Electrical supply
13 -  2.17.3 Switching off electrical supply
13 -  2.17.4 Failure of pressurization
14 -  2.17.5 Separate rooms or enclosures
14 -  2.17.6 Other protective measures
14 -  2.18 INSPECTION DOORS
15 -  SECTION 3 ENCLOSURES HAVING NO INTERNAL SOURCE OF FLAMMABLE MATERIAL
15 -  3.1 GENERAL
15 -  3.2 LEVEL OF OVERPRESSURE
15 -  3.3 PROTECTION REQUIREMENT
15 -  3.3.1 Switching off electrical supply
15 -  3.3.2 Alarm
16 -  SECTION 4 ROOMS HAVING NO INTERNAL SOURCE OF FLAMMABLE MATERIAL
16 -  4.1 GENERAL
16 -  4.2 LEVEL OF OVERPRESSURE
16 -  4.3 PROTECTIVE GAS FLOW
16 -  4.4 PROTECTION REQUIREMENT
16 -  4.4.1 General
16 -  4.4.2 Rooms located within Class I Zone 1 areas
17 -  4.4.3 Rooms located within Class I Zone 2 areas
17 -  4.4.4 Rooms located within Class II areas
18 -  SECTION 5 ENCLOSURES HAVING AN INTERNAL SOURCE OF FLAMMABLE GAS OR VAPOUR
18 -  5.1 GENERAL
18 -  5.2 DESCRIPTION OF TECHNIQUES
18 -  5.2.1 Continuous dilution with air
18 -  5.2.2 Pressurization with inert gas
18 -  5.3 LEVEL OF OVERPRESSURE
18 -  5.4 OUTLET APERTURES
18 -  5.5 ASSESSMENT OF THE INTERNAL RELEASE
18 -  5.5.1 General
18 -  5.5.2 Type and magnitude
19 -  5.5.3 Combinations of release
19 -  5.6 PROTECTION REQUIREMENTS
19 -  5.6.1 Energizing.
19 -  5.6.2 Switching off electrical supply
20 -  5.6.3 Alarm only
20 -  5.7 SUPPLY OF PROTECTIVE GAS
22 -  SECTION 6 ASSESSMENT AND TESTS
22 -  6.1 GENERAL
22 -  6.2 TYPE VERIFICATION AND TESTS
22 -  6.3 PRESSURIZATION TEST
22 -  6.4 MINIMUM OVERPRESSURE TEST
22 -  6.4.1 Test conditions
22 -  6.4.2 Number of tests
22 -  6.5 IMPACT TEST
23 -  SECTION 7 MARKING
24 -  APPENDIX A - DUCTS FOR PROTECTIVE GAS SUPPLY
27 -  APPENDIX B - GUIDELINES FOR ASSESSING THE TYPE OF RELEASE WITHIN ENCLOSURES
27 -  B1 GENERAL
27 -  B2 NO NORMAL RELEASE
27 -  B3 LIMITED NORMAL RELEASE
28 -  B4 LIMITED ABNORMAL RELEASE
28 -  B5 UNLIMITED ABNORMAL RELEASE
29 -  APPENDIX C - DISCUSSION OF PROTECTION REQUIREMENTS FOR CONTINUOUS DILUTION
29 -  C1 SCOPE
29 -  C2 PRINCIPLE
29 -  C3 NORMAL INDUSTRIAL IGNITION-CAPABLE ELECTRICAL EQUIPMENT IN ZONE 2 OR A NON-HAZARDOUS AREA
29 -  C3.1 Equipment with no normal release
29 -  C3.2 Equipment with normal release
29 -  C4 NORMAL INDUSTRIAL IGNITION-CAPABLE ELECTRICAL EQUIPMENT IN ZONE 1
30 -  C5 EQUIPMENT WITH NO SOURCE OF IGNITION IN NORMAL OPERATION, IN CLASS I ZONE 2 OR A NON-HAZARDOUS AREA
30 -  C6 EQUIPMENT WITH NO SOURCE OF IGNITION IN NORMAL OPERATION IN ZONE 1 AREAS

Abstract

Specifies requirements for the design, construction and testing of rooms and enclosures of electrical equipment in which the entry of flammable gas or vapour is prevented by maintaining the air (or other non-flammable gas) within the room or enclosure at a specified pressure above that of the external atmosphere. Requirements for the use of pressurized rooms and enclosures in Class II, combustible dust areas are also included.

RECONFIRMATION NOTICE
Technical Committee EL-014 has reviewed the content of this publication and in accordance with Standards Australia procedures for reconfirmation, it has been determined that the publication is still valid and does not require change.
Certain documents referenced in the publication may have been amended since the original date of publication. Users are advised to ensure that they are using the latest versions of such documents as appropriate, unless advised otherwise in this Reconfirmation Notice.
Approved for reconfirmation in accordance with Standards Australia procedures for reconfirmation on 8 April 2013.
The following are represented on Technical Committee EL-014:

Australian Chamber of Commerce and Industry
Australian Industry Group
Australian Institute of Petroleum
Australian Petroleum Production and Exploration Association
Australian Pipeline Industry Association
Aviation and Marine Engineers Association
Bureau of Steel Manufacturers of Australia
Department of Natural Resources and Mines, QLD
Department of Trade and Investment, Regional Infrastructure and Services, NSW
Electrical Compliance Testing Association
Electrical Contractors Association of New Zealand
Engineers Australia
Institute of Electrical Inspectors
Institution of Professional Engineers New Zealand
Ministry of Business, Innovation and Employment (New Zealand)
New Zealand Employers and Manufacturers Association (Central)
WorkCover New South Wales


To view or download a copy of the reconfirmation notice please go to the reconfirmation link near the top of this page.

Scope

This Standard specifies requirements for the design, construction and testing of pressurized rooms or pressurized enclosures, type of protection 'p', intended for use in Class I, Zone 1 and Zone 2 or Class II explosive atmospheres. While this standard covers enclosures with an internal release of flammable gas or vapour, it does not cover rooms with such a release, e.g. analyser houses nor rooms or enclosures with an internal release of combustible dust.

The requirements contained in this Standard are supplementary to those in AS 2380.1.

NOTES:
1 The classification of explosive atmospheres, termed hazardous areas, is dealt with in AS 2430. Further guidance may be obtained from Handbook SAA HB13.
2 Equipment with large areas which are subjected to pressures in excess of 1 kPa (e.g. sheet metal switchboard enclosures) may require approval from the relevant authority responsible for pressure vessel legislation in the State or Territory in which the enclosure is to be installed.
3 Rooms in which there is an internal release of flammable gas or vapour e.g. analyser houses are covered by IEC 79-16.
4 Areas not covered by this standard may be treated by protection by ventilation in accordance with AS 1482.
5 To minimise the risk of failure of an enclosure due to rupturing arc faults safeguarding against potential fault currents of an installation, especially where levels exceed 6 KA, should be provided.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	Standards Australia
ProductNote	Reconfirmed 26-07-2013
Pages
ISBN
Committee	EL-014
Supersedes	AS 1825-1982 AS 1021-1980 DR 89196