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Hawke EnclosuresTechnical Data

The intent of this section of the catalogue is to identify important features that may be useful in the selection and installation of explosion protected electrical equipment. Of flammable substances in the form of gases, vapours, mists, dusts or fibresIn which, after ignition has occurred, combustion spreads to the entire unburned mixtureUnder atmospheric conditionsWith airAn explosive atmosphere is defined as a mixture: - There are numerous different regulations, codes, guidelines and standards for the design, installation and maintenance of electrical and non-electrical systems for use in potentially explosive atmospheres. The type of operational facility, geographic location, operator practice, local and national legislation, authority having jurisdiction etc. will determine many of the design and installation rules permitted. A fixed or floating petroleum facility located offshore, for example, would not be designed or classified in the same manner as an onshore petrochemical facility. The purpose of area classification is to provide a basis for the correct selection, installation and location of electrical and non-electrical equipment in those areas. Areas must be classified depending on the properties of the flammable vapours, liquids, gases, mists, combustible dusts or fibres that may be present and the likelihood that a flammable or combustible concentration or quantity is present.The aim of area classification is to avoid ignition of flammable releases that may occur in the operation of facilities. The intent is to reduce to an acceptable minimum level the probability of a flammable atmosphere and an ignition source occurring at the same time.Area classification is the division of a facility into three-dimensional hazardous areas and non-hazardous areas and the sub-division of the hazardous area into 'Zones'.Hazardous areas may be sub-divided into three Zones as follows: -

1.0 Potentially Explosive Atmospheres2.0 Area Classification (Classification of Locations)3.0 CENELEC and IEC

Technical Data

3.1 Area Classification An area in which an explosive atmosphere is constantly present, or present for long periods.An area in which an explosive atmosphere is likely to occur in normal operation.(Rough Guide: 10 hours or more / year but less than 1,000 hours / year)An area in which an explosive atmosphere is not likely to occur in normal operation and if it occurs, it will exist only for a short time.(Rough Guide: Less than 10 hours / year) Zone 0 Zone 1Zone 2 Flammable gases and vapours

To the best of our knowledge the information contained in this leaflet, is accurate at the time of going to print and the company reserves the right to improve or modify any product illustrated without notification. The company is unable to accept liability for any inaccuracies, errors or omissions that may exist. It is the customer's responsibility to ensure that the product is suitable for their application. Copyright Condition: This document shall be used only for the purpose for which it is provided and no reproduction or publication of the document may be made and no article may be manufactured or assembled in accordance with information contained in the document without prior written consent of the owner. All copyright reserved-H ubbell Ltd. This document and all copyright therein is the property of: Hawke International a division of Hubbell Ltd. (A member of the Hubbell Group of Companies).

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HWK05 Mar '02