Each country has its own regulations which may differ. National requirements might be needed for final approval of installation e.g. in Russia, Brazil, Australia or Japan but generally relate to one of the main standards below:
- IEC: International Electrotechnical Commission
- EN: European Norm
- NEC: National Electrical Code (Articles 500, 505 or 506) in North America
| International standards - IEC |
International standards for all electrical, electronic and related technology are issued by IEC. Founded in 1906, it is made of more than 60 participating countries, with the major goals being:
- Define requirements for making the global market world wide efficient
- Improve efficiency in industrial processes
- Improve human health and safety
- Protect the environment
The IECEx Scheme is an International Conformity Assessment Scheme covering Apparatus for Explosive Atmospheres, as the Internationally accepted means of demonstrating claimed compliance with IEC Standards prepared by IEC TC31(Technical Committee for Explosive equipment).
IECEx Scheme was created in September 1999 to cover Equipment for use in Explosive Atmospheres to reduce and ultimately eliminate the wasteful duplication of Ex testing and certification that has occurred worldwide for some time.
The IECEx caters for differing countries (25) whose national standards are either identical to those of the IEC or else very close to IEC standards. The goal is to help manufacturers reduce costs and time while developing and maintaining uniform product evaluation to protect users against products that are not in line with the required level of safety. The IECEx is a voluntary scheme that provides an internationally accepted means of proving compliance of products and services with an IEC standard.
The European standards are issued by European Standards Bodies:
- CEN - European Committee for Standardization - created in 1961
- CENELEC - European Committee for Electro technical Standardization - created in 1973, including 19 European countries
These bodies have in charge to produce
harmonised standards to cover the electrical and mechanical fields and give the technical means to achieve the objectives of
EHSRs stated in ATEX Directives.
In 1996, IEC and CENELEC made a co-ordination agreement to develop new standards called the 'Dresden agreement'. It means that since September 1996 the same document is submitted to IEC and CENELEC simultaneously and the standards are published at same time and are identical.
This work was paused for the period 1998-2000 due to the introduction of ATEX Directive until harmonised standards have been published. This procedure was re-introduced in 2001 which means that the IEC standards shall be updated over the coming years in accordance with the EHSRs of ATEX Directive.
The general standards for the electric motors according to North American rules are:
- NEMA Motors and Generator (MG-1) in the U.S.
- C22.2 No. 100-95 in Canada.
The general description of hazardous areas and protection types are presented in the National Electric Code (NEC) published by National Fire Protection Association (NFPA) and in Canadian Electric (CE Code) published by CSA. More specific requirements can be found e.g. from several IEEE and UL publications.
Electrical equipment used in hazardous locations, classified according to North American rules, shall be approved by an authorized body or the manufacturer.
The equipment for Division 1, Zone 0 or 1 areas shall always be approved by an authorized body e.g. UL, CSA or FM.