IEC 61241-4 pdf download – Electrical apparatus for use in the presence of combustible dust – Part 4: Type of protection “pD”

IEC 61241-4 pdf download – Electrical apparatus for use in the presence of combustible dust – Part 4: Type of protection “pD”
1 Scope
This part of lEC 61241 gives requirements on the design, construction, testing and marking ofelectrical apparatus for use in combustible dust atmospheres in which a protective gas (air orinert gas), maintained at a pressure above that of the external atmosphere, is used to preventthe entry of dust which might otherwise lead to the formation of a combustible mixture withinenclosures which do not contain a source of combustible dust.
This standard contains the specific requirements for construction and testing, including
protective requirements that apply to electrical apparatus with type of protection pressurization”pD” intended for use in potentially combustible dust atmospheres.
This standard includes the requirements for the construction of the enclosure and its
associated components, including, if any, the inlet and outlet ducts for the protective gas, andfor the safety provisions and devices necessary to ensure that pressurization is establishedand maintained for type of protection pressurization “pD”.
Requirements for pressurized enclosures with an internal source of dust release are notincluded in this standard.
This standard does not cover the requirements for pressurized rooms with or without internalsources of dust release.
This standard does not apply to dusts of explosives which do not require atmospheric oxygenfor combustion or to pyrophoric substances.
This standard does not cover combined gas and dust hazard.Those requirements are underconsideration.
The requirements contained in this standard are supplementary to those in lEC 61241-1-1.
2Normative references
The following normative documents contain provisions which, through reference in this text,constitute provisions of this part of lEC 61241.For dated references,subsequent amendmentsto, or revisions of, any of these publications do not apply.However, parties to agreementsbased on this part of IEC 61241 are encouraged to investigate the possibility of applying themost recent editions of the normative documents listed below.For undated references, thelatest edition of the normative document referred to applies. Members of lEC and ISO maintainregisters of currently valid International Standards.
IEC 60034-1:1996,Rotating electrical machines – Part 1: Rating and performance 1)
CEI61241-1-2:1999，Matériels electriques destines aetre utilises en presence de poussierescombustibles – Partie 1-2: Matériels electriques protéges par enveloppes et limitation de latemperature de surface – Selection, installation et maintenance
CEI61241-3:1997, Materiels électriques destines aetre utilises en presence de poussierescombustibles – Partie 3: Classification des emplacements ou des poussieres combustiblessont ou peuvent etre presentes
Definitions
Pour les besoins de la présente partie de la CEl 61241, les definitions de la CEI61241-1-1,ainsi que les definitions suivantes sont applicables.
3.1
type de protection epD”
technique consistant a entretenir, dans une enceinte, une surpression dun gaz protecteur parrapport a la pression atmosphérique environnante afin dempecher la formation d’une
atmosphere de poussiere explosive à linterieur de l’enceinte
3.2
surpression
pression supérieure a la pression ambiante dans une enceinte pressurisée
3.3
pressurisation
technique empechant la penetration, dans une enceinte, de latmosphere poussiereuseexterieure, potentiellement explosive, par maintien a lintérieur d’un gaz protecteur a unepression superieure a celle de l’atmosphere exterieure
3.4
gaz protecteur
air ou gaz inerte utilise pour entretenir une surpression.
NOTE Pour les besoins de la presente norme, on entend par gaz inerte ‘azote, le dioxyde de carbone,largon outout autre gaz qui, lorsque m elange a loxygene dans une proportion de 4 pour 1 telle que celle de lair, n’aggravepas les propriet es d allumage et de combustion telles que les limites de la combustibilite.
3.5
enceinte
ensemble des parois entourant les parties sous tension des appareils électriques, y comprisportes, capots, et traversées de cables, de tiges, de pivots et d’arbres, assurant la protectionde lappareil
3.6
enceinte pressurisee
enceinte dans laquelle un gaz protecteur est maintenu a une pression supérieure a celle del’atmosphere exterieure
NOTE L’enceinte pressuriste peut egalement etre ou non ‘enceinte entourant les parties sous tension etassurant la protection de lappareil electrique contre drautres risques.