AS/NZS 61241.2.3:2000

1 - AS/NZS 61241.2.3:2000 ELECTRICAL APPARATUS FOR USE IN THE PRESENCE OF COMBUSTIBLE DUST - TEST METHODS-METHOD FOR DETERMINING...
4 - PREFACE
5 - CONTENTS
7 - 1 Scope
7 - 2 Normative references
8 - 3 Definitions
8 - 3.1 dust:
8 - 3.2 combustible dust:
8 - 3.3 spark discharge:
8 - 3.4 minimum ignition energy (of a combustible dust/air mixture):
8 - 3.5 ignition:
8 - 3.6 ignition delay time:
9 - 4 Test apparatus
9 - 4.1 Spark generation circuit
9 - 4.2 Test vessel
9 - 5 Test sample
10 - 6 Procedure
10 - 6.1 Brief description
11 - 6.2 Calibration
11 - 6.3 Test report
11 - 6.3.1 Product characteristics
11 - 6.3.2 Characteristics of the test apparatus
11 - 6.3.3 Results
11 - 6.3.4 Report form
12 - Annex A - Examples of spark-generating systems
12 - A.1 General
12 - A.2 Triggering by auxiliary spark using three-electrode system
13 - A.3 Triggering by electrode movement
13 - A.4 Triggering by voltage increase (trickle-charging circuit)
14 - A.5 Triggering by auxiliary spark, using normal two-electrode system (trigger transformer in discharge circuit)
20 - Annex B - Significance of minimum ignition energy
23 - Annex C - Bibliography

Specifies a method of test to determine the minimum ignition energy of a dust/air mixture by an electrically generated high-voltage d.c. spark. This test method is intended to develop data to be used in deciding whether or not combustible dust/air mixtures are considered to be ignitable with respect to electrical discharge. This Standard is identical with and has been reproduced from IEC 61241-2-3:1994.

This part of AS/NZS 61241 specifies a method of test to determine the minimum ignition energy of a dust/air mixture by an electrically generated high-voltage d.c. spark. This test method is intended to develop data to be used in deciding whether or not combustible dust/air mixtures are considered to be ignitable with respect to electrical discharge. It is intended that the dust be tested in a form (particle size, moisture content, etc.) representing conditions of actual use so that assessment of the hazard present can be made. Ignition energies determined by this method would be compared with ignition energies of other dusts to assess the relative hazard with regard to ignition by an electrical or electrostatic discharge, thereby permitting decisions to be made on the suitability of electrical apparatus for installation in areas where combustible dust is present.The test method is not suitable for use with recognized explosives, gunpowder, dynamite, explosives which do not require oxygen for combustion; pyrophoric substances, or substances or mixtures of substances which may under some circumstances behave in a similar manner. Where any doubt exists about the existence of a hazard due to explosive properties, an indication may be obtained by placing a very small quantity of the dust in question on the heated surface of the apparatus described in AS/NZS 61241.2.1, heated to 400°C.NOTE - Precautions should be taken to safeguard the health of personnel conducting the tests against the risk of fire, explosion and/or the effects, including toxic effects of combustion. Compliance with this international standard does not itself confer immunity from legal obligations.Annex B of this section includes guidance on the significance of minimum ignition energy with respect to electrostatic discharges.

First published as AS/NZS 61241.2.3:2000.