IEC/SC 31H - IEC_SC_31H

Specifies general requirements, additional to those required for basic electrical safety, for the selection of electrical apparatus and instruments and associated equipment, and for the installation of electrical apparatus to ensure safe use in areas where combustible dust may be present in quantities which could lead to a fire or explosion hazard. 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.

This part of EN 61241 specifies requirements for the construction and testing of intrinsically safe apparatus intended for use in potentially explosive dust cloud or dust layer environments and for associated apparatus that is intended for connection to intrinsically safe circuits which enter such environments.

Gives requirements on the design, construction, testing and marking of electrical apparatus for use in combustible dust atmospheres in which a protective gas (air or inert gas), maintained at a pressure above that of the external atmosphere, is used to prevent the entry of dust which might otherwise lead to the formation of a combustible mixture within enclosures which do not contain a source of combustible dust.

Specifies general requirements for the design, construction, testing and marking of electrical apparatus protected by any recognized safeguard technique for use in areas where combustible dust may be present in quantities that could lead to a fire or explosion hazard. 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. The contents of the corrigendum of November 2005 have been included in this copy.

This part of EN 61241 is intended to be applied by users and covers factors directly related to the inspection and maintenance of electrical installations within hazardous areas only. It does not include conventional requirements for electrical installations, nor the testing and certification of electrical apparatus. This standard supplements the requirements laid down in EN 60364-6-61. NOTE: The text is based on EN 60079-17

Applicable to electrical apparatus protected by encapsulation type of protection mD 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. Specifies requirements for design, construction and testing of electrical apparatus, parts of electrical apparatus and Ex components where the rated voltage does not exceed 10 kV. 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.

Deals with the classification of areas where explosive dust/air mixtures and combustible dust layers are present, in order to permit the proper selection of equipment for use in such areas. The principles of the standard can also be followed when combustible fibres or flyings may cause a hazard. To be applied where there can be a risk due to the presence of explosive dust/air mixtures or combustible dust layers under normal atmospheric conditions.

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. Specifies requirements for design, construction and testing of electrical apparatus. The ignition protection is based on the limitation of the maximum surface temperature of the enclosure and on 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.

Superseded by EN 61241-10:2004

Superseded by EN 61241-1:2004 & EN 61241-0:2006

Superseded by EN 61241-14:2004 and EN 61241-17:2005

This European Standard specifies two test methods for determining the minimum ignition temperatures of dust for the purpose of selecting electrical apparatus for use in the presence of combustible dust in accordance with EN 50281-1-2:1998 and constructed in accordance with EN 50281-1-1:1998. These methods are not suitable for use with substances having explosive properties. Method A (clause 4) is applicable to the determination of the minimum temperature of a prescribed hot surface which will result in the decomposition and/or ignition of a layer of dust of a specified thickness deposited on it. The method is particularly relevant to industrial equipment with which dusts are present on hot surfaces in thin layers exposed to the atmosphere. Method B (clause 5) is applicable to the determination of the minimum temperature of a prescribed hot surface which will result in the ignition of a cloud of given sample of dust or other particulate solid. The test is intended to be carried out as a complementary test after determining the minimum ignition temperature of a dust layer by method A of this European Standard. NOTE 1 concerning method B: Because the method of operation of the furnace gives short residence times for dust particles within it, this method of test is applicable to industrial equipment where dust is present as a cloud for a short time. This method of test is of small scale and the results are not necessarily representative of all industrial conditions NOTE 2 concerning method B: The method is not applicable to dusts which may, over a longer period of time than provided for in the test method, produce gasses from deposits generated during pyrolysis or smouldering

This European Standard is applicable to electrical apparatus protected by enclosure and temperature limitation for use in areas where combustible dust may be present in quantities which could lead to a fire or explosion hazard. This standard gives guidance on the selection, installation and maintenance of electrical apparatus. NOTE: EN 50281-1-1 specifies requirements for the design, construction and testing of electrical 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. The application of electrical apparatus in atmospheres that may contain explosive gas as well as combustible dust, whether simultaneously or separately, requires additional protection measures. The principles of this standard can also be followed when combustible fibres or flyings 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 for use in mines susceptible to firedamp; nor does it take account of any risk because of 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 enclosure and temperature limitation

This European Standard is applicable to electrical apparatus protected by enclosure and temperature limitation for use in areas where combustible dust may be present in quantities which could lead to a fire or explosion hazard. This standard specifies requirements for design, construction, and testing of electrical apparatus. EN 50281-1-2 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. Apparatus within the scope of this standard may also be subjected to additional requirements in other publications - for example, EN 50014, Electrical apparatus for potentially explosive atmospheres. 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. The principles of this standard may also be followed when combustible fibres or flyings 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 for use in mines susceptible to firedamp; nor does it take account of any risk caused by 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 enclosure and temperature limitation

Specifies a test method to determine, by application of a d.c. voltage, the electrical resistivity of a layer of dust. Is to be used in the design, construction, testing and application of electrical apparatus for use in the presence of combustible dust. This publication has the status of a technical report.