Electrical Equipment in Hazardous Areas (EEHA)
A hazardous area is one in which an explosive atmosphere is present or may be expected to be present, in quantities such as to require special precautions for the construction, installation and use of electrical equipment [AS NZS 2381:2005].
Hazardous areas are classified into zones according to the likelihood of an explosive atmosphere being present. The classification allows the definition of the equipment protection levels required and to be specified for each location. The classification may be used in conjunction with an assessment of the consequences of an ignition.
Hazardous areas are classified into zones according to the likelihood of an explosive atmosphere being present. The classification allows the definition of the equipment protection levels required and to be specified for each location. The classification may be used in conjunction with an assessment of the consequences of an ignition.
By ensuring compliance with hazardous area competencies for the classification and the electrical design of electrical equipment for hazardous area, BESST Engineering provide EEHA design and consultation, including:
- Classification of hazardous areas
- Provision of design input to reduce the impact of hazardous areas in the plant
- Design of the electrical and instrumentation systems to be used in the hazardous area
- Specification of the electrical equipment and enclosures to suit installation in the hazardous area
- Sizing and specification of the electrical cables
- Provision of complete design documentation including zone classification drawings, area layout drawings, single line diagrams, schematics, bills of materials and installation specifications\
- Provision of the documentation for the hazardous area dossier
Australian Standards
AS / NZS 3000: Electrical Installations, refers to hazardous areas (explosive gas or combustible dusts) in section 7.7. The requirements of this clause apply to:
"The selection of electrical equipment and its installation to ensure safe use in areas where flammable or combustible material materials are produced, prepared, processed, handled, stored or otherwise exist, and therefore may give rise to an explosive atmosphere."
"The selection of electrical equipment and its installation to ensure safe use in areas where flammable or combustible material materials are produced, prepared, processed, handled, stored or otherwise exist, and therefore may give rise to an explosive atmosphere."
Classification of Hazardous Areas
The responsibility for the classification of hazardous areas is identified as resting with the persons or parties in control of the installation. The requirements for the classification are nominated as contained in AS/NZS 60079.10 and AS/NZS 61241.10.
Electrical Equipment for Hazardous Areas
The requirements for the selection of electrical equipment for use in hazardous areas must comply with AS/NZS 2381.1 or AS/NZS 61241.14
The installation of electrical equipment in hazardous areas must comply with AS/NZS 2381.1 or AS/NZS 61241.14.
“Guidance on additional competencies, inspection techniques and maintenance and repair methods is given in the applicable parts of the AS/NZS 2381 and AS/NZS 61241 series.”
Australian / New Zealand Standard AS/NZS 4761 specifies the competencies required for work associated with electrical equipment for hazardous areas. BESST Engineering has nationally recognised competencies that also meet the requirements of this standard, for classifying hazardous areas and designing electrical systems for hazardous areas, including:
The installation of electrical equipment in hazardous areas must comply with AS/NZS 2381.1 or AS/NZS 61241.14.
“Guidance on additional competencies, inspection techniques and maintenance and repair methods is given in the applicable parts of the AS/NZS 2381 and AS/NZS 61241 series.”
Australian / New Zealand Standard AS/NZS 4761 specifies the competencies required for work associated with electrical equipment for hazardous areas. BESST Engineering has nationally recognised competencies that also meet the requirements of this standard, for classifying hazardous areas and designing electrical systems for hazardous areas, including:
- Hazardous area classification procedures and techniques
- Gas / vapour installations and combustible dusts
- Documentation of the classification
- Protection techniques
- Electrical equipment selection
- Earthing and equipotential bonding requirements
- Ex i entity calculations
- Ex e motor protection
- Cable de-rating requirements
- Maximum dissipated power calculations
- General design principles
The competencies are not applicable to underground coal mining applications.