YOKOGAWA AXFA14G - Installation and Operating Precautions for Tiis Flameproof Equipment (Ex-B03 E)

<INSTALLATION AND OPERATING PRECAUTIONS FOR TIIS FLAMEPROOF EQUIPMENT>
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EX-B03E
INSTALLATION AND OPERATING PRECAUTIONS FOR TIIS
FLAMEPROOF EQUIPMENT
ApparatusCertiedUnderTechnicalCriteria
(IEC-compatible Standards)
1. General
The following describes precautions on electrical
apparatusofameproofconstruction(hereinafterreferred
toasameproofapparatus)inexplosion-protected
apparatus.
FollowingtheLabourSafetyandHealthLawsofJapan,
ameproofapparatusissubjectedtotypeteststomeet
either the technical criteria for explosionproof electrical
machineryandequipment(standardsnoticationno.
556fromtheJapaneseMinistryofLabour)(hereinafter
referred to as technical criteria), in conformity with the IEC
Standards,orthe“RecommendedPracticeforExplosion-
ProtectedElectricalInstallationsinGeneralIndustries,”
publishedin1979.Thesecertiedapparatuscanbeused
inhazardouslocationswhereexplosiveorinammable
gases or vapours may be present.
Certiedapparatusincludesacerticationlabelandan
equipmentnameplatewiththespecicationsnecessary
for explosion requirements as well as precautions on
explosionprotection.Pleaseconrmtheseprecautionary
itemsandusethemtomeetspecicationrequirements.
For electrical wiring and maintenance servicing, please
referto“InternalWiringRules”intheElectricalInstallation
TechnicalStandardsaswellas“USER’SGUIDELINES
for Electrical Installations for Explosive Gas Atmospheres
inGeneralIndustry,”publishedin1994.
Tomeetameproofrequirements,equipmentthatcanbe
termed“ameproof”must:
(1) BecertiedbyaJapanesepublicauthorityin
accordance with the Labour Safety and Health
LawsofJapanandhaveacerticationlabelinan
appropriate location on its case, and
(2) Beusedincompliancewiththespecicationsmarked
onitscerticationlabel,equipmentnameplateand
precautionary information furnished.
2. Electrical Apparatus of
Flameproof Type of Explosion-
Protected Construction
Electricalapparatuswhichisofameproofconstruction
issubjectedtoatypetestandcertiedbytheJapanese
Ministry of Labour aiming at preventing explosion caused
by electrical apparatus in a factory or any location where
inammablegasesorvapoursmaybepresent.The
ameproofconstructionisofcompletelyenclosedtype
and its enclosure shall endure explosive pressures in
cases where explosive gases or vapours entering the
enclosure cause explosion. In addition, the enclosure
constructionshallbesuchthatamecausedbyexplosion
does not ignite gases or vapours outside the enclosure.
Inthismanual,theword"ameproof"isappliedto
theameproofequipmentcombinedwiththetypesof
protection"e","o","i",and"d"aswellasameproof
equipment.
3. Terminology
(1) Enclosure
An outer shell of an electrical apparatus, which encloses
livepartsandthusisneededtocongureexplosion-
protected construction.
(2) Shroud
A component part which is so designed that the fastening
of joint surfaces cannot be loosened unless a special tool
is used.
(3) Enclosure internal volume
This is indicated by:— the total internal volume of the
ameproofenclosureminusthevolumeoftheinternal
components essential to equipment functions.
(4) Path length of joint surface
On a joint surface, the length of the shortest path through
whichameowsfromtheinsidetooutsideofthe
ameproofenclosure.Thisdenitioncannotbeappliedto
threaded joints.
(5) Gaps between joint surfaces
The physical distance between two mating surfaces,
or differences in diameters if the mating surfaces are
cylindrical.
Note: The permissible sizes of gaps between joint surfaces,
the path length of a joint surface and the number of joint
threads are determined by such factors as the enclosure’s
internal volume, joint and mating surface construction,
andtheexplosionclassicationofthespeciedgasesand
vapours.