This part of IEC 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 . IEC 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 fibers or flying 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.