CAN/CSA-E1241-1-1-95

1.1 Scope This section of IEC 1241-1 is applicable to electrical apparatus protected by enclosure for use in areas where combustible dust may be present in quantities which could lead to a fire or explosion hazard. Apparatus within the scope of this standard may also be subjected to additional requirements in other publications - for example, IEC 79. This section specifies requirements for design, construction, and testing of electrical apparatus. Section 2 of IEC 1241-1 gives guidance on the selection, installation, and maintenance of the apparatus. The ignition protection is based on the limitation of the maximum surface temperature of the enclosure, and on the restriction of dust ingress into the enclosure by the use of "dust-tight" or "dust-protected" enclosures. This standard does not apply to dusts of explosives which do not require atmospheric oxygen for combustion, or to pyrophoric substances. The application of electrical apparatus in atmospheres which may contain explosive gas as well as combustible dust, whether simultaneously or separately, requires additional protection measures. This standard does not take account of any risk due to an emission of flammable or toxic gas from the dust. The principles of this standard can also be followed when combustible fibres or flyings cause a hazard. Where the apparatus has to meet other environmental conditions, for example, protection against ingress of water and resistance to corrosion, the method of protection used shall not adversely affect the integrity of the enclosure.