IEEE 303:2004 pdf free download – IEEE Recommended Practice forAuxiliary Devices for Rotating Electrical Machines in Class l,Division 2 and Zone 2 Locations
3.1 Definitions
F cr the purposes of this standard the fol1owing term s and defiritions apply.T’re Athcritative Dictionary of了EEE Stadards Terms, SeventhEditiori’should be referenced for terms rot defined in this clause.
3.1.l auxiliary devices: Components installed either integrally within the rotating electrical m actine,1ocated adjacent to or m ounted on the machine, or attached to its terminals for the purpose of mornitoring theoperating conditions or protection
3.1.2 ClassI,Div ision 2: A location 1) in which volatile flamm able liquids or flammable gases and vapor sare handed, processed ar used, but in which the liquid, vapocrs or gases will norm ally be confined withinclosed containers or closed systens fr an which they can escape only in case of accidertal rupture or treak-down of suh containers or systemns, or in case of abnorm al operation of equpment, or 2′) in which ignitatleconcentr ations of gases or vapors are norm ally preverted by positive mecharical venti1ation, and whichmight become hazardous through failuxe or abnorm aloperatian of the ventilating equpmernt; ar 3) that isadjacent to a Class I, Division 1 1ocaion, and to which ignitable c ncentration of gases or vapors mighntoccasionally be com muricated unless such c amm urication is preventedby adequate positive pressure venti-1ation from a source of clean air and effective safeguards against verti1 ation failure are provided.
NOTE—Refr to the latest edition of NFPA 70-2005, Chapter 5, Articles 500 and 505.Fx a guide inestablishing thelimnits of these lbcations, refer to API RP 500-1997; API RP 505-1997, and NFPA 497-2004.10
3.15 exp bsion-p roof encbsure: An enclosure designed and constructed to withstand an explosion of aspecified flarm matle gas ar vapor that may occur within it, and to prevent the ignition of flarm matle gas orvapor in the atm osphere surrounding the enclosxe by sparks, flashes, ar explosions af the specified gas ctvapor that may occur within the enclosure.
3.1.6 flameproof enclosure:F1amn eproof enclosure“c&” :An enclosure in which the parts which can ignite anexplosive atn osphere are placed and which can withstand the pressure developed duwing an internalexplosicn of an explosive mixture，and which preverts the transmn issicn af the exp1osion to the explosiveatm osphere surr ounding the enclosure.
NOTE—Refr to ASNzS 6079.1-2002; CENELEC EN50018-2000;CANICSA-E60079-1:02, IEC6Q079-1:001,and UL60079-1-2002.
3.1.7 fammability classifiration: F1am mable gases or vapcors of flamm able liquids are segregated irtogroups by the degree of severity relevant to the flame tr ansmn ission characteristics andexplosion pressure ofgases or vapors within that group.For the re spective area classification methodologies, those groups are:
3.1 8 hazardous area:An area in which a gas or vapor is presernt, or m ay be expected to be present in quan-tities sufficient to produe explosive ar ignitable nixtures, and whichrequire appr opriate precautions for thedesign, m anufacturing instal1ation and operaticn of electrical apparatus.
3.1 9 hermetrally sealed : A device which is so constructed that the externa atrnospher e carnot gain acc essto the interior and in which the seal is made by soldering tr azing w elding or the fusion of gass to metal.Under NFPA70-2005, hermetically sealed devices are perm itted for current- interrupting contacts.
NOTE—See also the sealed device requirements of CENELEC EN 50021-1999, cSA C22.2 No.213-M1987(R1999);CANICSA-E60079-15:02; IEC 60079-15:2001;UL 16041994;and UL. 60079-15-2002.
3.1.10 intrinsically safe circuit: A circut in which any spark ar therm al efect is incapable of causingignition f a mixtre of flarn mable or com tbustitle m aerial in air under pre scribed test canditions. Testconditions generally consider opering shorting grounding, or field wiring, al ong withfailures in the circuit.NOTE—Reir to AS/Nzs 600r9.11 :2000;CENELEC EN 50020-2002;CANICSA C22.2 No.157-1992;CANICSA-E60079-11:02; IEC 60079-11:1999;UL913-2002; and UL60079-11-2002.
3.1.ll nonincendie: A protective tectrnique where, under norm a operating c ondtions, any arcing or ther-mal effects are not capable of igniting the flarm mable gas, vapor, or cast-in-air mixture.
NOTE—Refr to CENELECEN 50021-1999; csA C22.2 No. 213-M1987(R199);CANICSA-E60079-1502, IEC60079-15:2001;UL 16041994; and UL60079-15-2002.