AS/NZS 61241.1.1:1999

1 - AS/NZS 61241.1.1:1999 ELECTRICAL APPARATUS FOR USE IN THE PRESENCE OF COMBUSTIBLE DUST - ELECTRICAL APPARATUS PROTECTED BY...
4 - PREFACE
5 - CONTENTS
6 - INTRODUCTION
7 - 1 Scope
7 - 2 Normative references
9 - 3 Definitions
9 - 3.1 dust
9 - 3.2 combustible dust
9 - 3.3 conductive dust
9 - 3.4 explosive dust atmosphere
9 - 3.5 minimum ignition temperature of a dust layer
9 - 3.6 minimum ignition temperature of a dust cloud
10 - 3.7 dust ignition protection (DIP)
10 - 3.8 dust-tight enclosure
10 - 3.9 dust-protected enclosure
10 - 3.10 maximum surface temperature
10 - 3.11 maximum permissible surface temperature
10 - 3.12 zones
10 - 3.13 zone 20
10 - 3.14 zone 21
10 - 3.15 zone 22
10 - 4 Construction
11 - 5 Enclosure materials
11 - 5.1 Non-metallic enclosures and non-metallic parts of enclosures
12 - 5.2 Enclosures containing light metals
12 - 6 Fasteners
13 - 7 Interlocking devices
13 - 8 Bushings
13 - 9 Materials used for cementing
13 - 10 Connection facilities and terminal compartments
13 - 11 Connection facilities for earthing or bonding conductors
14 - 12 Cable and conduit entries
16 - 13 Supplementary requirements for electrical apparatus for practice B for use in zone 20 or 21
16 - 13.1 Joints
17 - 13.2 Operating rods, spindles or shafts
18 - 13.3 Clearance of bolts
18 - 14 Rotating electrical machines
18 - 14.1
19 - 14.2
19 - 14.3
19 - 14.4Construction and mounting of the ventilating systems
19 - 14.5Clearances for the ventilating system for use in zone 20 or 21
19 - 14.6 Materials for external fans and fanhoods for use in zone 20 or 21
19 - 15 Switchgear
20 - 16 Fuses
20 - 17 Plugs and sockets
20 - 18 Luminaires
21 - 19 Caplights, caplamps and handlamps
21 - 20 Verification and tests
21 - 20.1 General
22 - 20.2 Verification of documents
22 - 20.3 Compliance of prototype or sample with documents
23 - 20.4 Type tests
23 - 20.4.1 General
23 - 20.4.2 Mechanical tests
25 - 20.4.3 Tests for dust exclusion by enclosures
26 - 20.4.4 Torque test for bushings in enclosures for use in zone 20 or 21
27 - 20.4.5 Thermal tests
28 - 20.4.6 Thermal shock test
28 - 20.4.7 Tests of non-metallic enclosures or of non-metallic parts of enclosures for use in zone 20 or 21
30 - 21 Routine verifications and tests
30 - 22 Manufacturer's responsibility
30 - 23 Verifications and tests on modified or repaired electrical apparatus
30 - 24 Clamping tests of non-armoured and braided cables
30 - 24.1 Cable entries with clamping by the sealing ring
31 - 24.2 Cable entries with clamping by filling compound
31 - 24.3 Cable entries with clamping by means of a clamping device
32 - 24.4 Tensile test
32 - 24.5 Mechanical strength
32 - 25 Clamping tests of armoured cables
32 - 25.1 Clamping tests where the armourings are clamped by a device within the gland
32 - 25.1.1 General
33 - 25.1.2 Tensile test
33 - 25.1.3 Mechanical strength
33 - 25.2 Clamping tests where the armourings are not clamped by a device within the gland
33 - 26 Marking
33 - 26.1 General
33 - 26.2 Markings
33 - 26.2.1 Marking of all electrical apparatus
33 - 26.2.2 Supplementary marking of apparatus for practice A
34 - 26.2.3 Supplementary marking of apparatus for practice B
35 - 27 Examples of marking
35 - 27.1 Practice A
35 - 27.1.1 Marking for zone 21
35 - 27.1.2 Marking for zone 22
35 - 27.2 Practice B
35 - 27.2.1 Marking for zone 21
35 - 27.2.2 Marking for zone 22

Specifies requirements for the design, construction and testing of electrical apparatus for use in areas where combustible dusts are or may be present, in quantities which could lead to a fire or explosion hazard. It is identical to and has been reproduced from IEC 61241-1-1:1999.

This part of AS/NZS 61241 is applicable to electrical apparatus protected by enclosures and surface temperature limitation for use in areas where combustible dust may be present in quantities which could lead to a fire or explosion hazard. It specifies requirements for design, construction and testing of electrical apparatus.NOTE AS/NZS 61241.1.2 gives guidance on the selection, installation and maintenance of the apparatus. Apparatus within the scope of this standard may also be subject to additional requirements in other standards for example, IEC 60079-0.The ignition protection is based on the limitation of the maximum surface temperature of the enclosure and other surfaces which could be in contact with dust and on the restriction of dust ingress into the enclosure by the use of "dust-tight" or "dust-protected" enclosures.The application of electrical apparatus in atmospheres which may contain explosive gas as well as combustible dust, whether simultaneously or separately, requires additional protective measures.Where the apparatus has to meet other environmental conditions, for example, protection against ingress of water and resistance to corrosion, additional methods of protection may be necessary. The method used is not to adversely affect the integrity of the enclosure.The principles of this standard may also be followed when combustible fibres or flyings cause a hazard.This standard does not apply to dusts of explosives which do not require atmospheric oxygen for combustion, or to pyrophoric substances.This standard is not applicable to electrical apparatus intended for use in underground parts of mines as well as those parts of surface installations of such mines endangered by fire damp and/or combustible dust. This standard does not take account of any risk due to an emission of flammable or toxic gas from the dust.This standard does not include other types of protection and is only applicable to protection by enclosures and surface temperature limitation.

First published as AS C358-1965.
Revised and redesignated as AS 2236-1979.
Second edition 1982.
Third edition 1985.
Fourth edition 1994.
Jointly revised and redesignated as AS/NZS 61241-1-1:1999.