SIST EN 50016:2003
(Main)Electrical apparatus for potentially explosive atmospheres - Pressurized apparatus p
Electrical apparatus for potentially explosive atmospheres - Pressurized apparatus p
Superseded by EN 60079-2:2004
Elektrische Betriebsmittel für explosionsgefährdete Bereiche - Überdruckkapselung p
Matériel électrique pour atmosphères explosibles - Surpression interne p
Električne naprave za potencialno eksplozivne atmosfere - Nadtlak "p"
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Standards Content (Sample)
SIST EN 50016:2003SLOVENSKImarec 2003
STANDARDElektrične naprave za potencialno eksplozivne atmosfere - Nadtlak "p"Electrical apparatus for potentially explosive atmospheres - Pressurized apparatus "p"©
Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljenoReferenčna številkaSIST EN 50016:2003(en)ICS29.260.20
EUROPEAN STANDARDEN 50016NORME EUROPÉENNEEUROPÄISCHE NORMJuly 2002CENELECEuropean Committee for Electrotechnical StandardizationComité Européen de Normalisation ElectrotechniqueEuropäisches Komitee für Elektrotechnische NormungCentral Secretariat: rue de Stassart 35, B - 1050 Brussels© 2002 CENELEC -All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.Ref. No. EN 50016:2002 EICS 29.260.20Supersedes EN 50016:1995English versionElectrical apparatus for potentially explosive atmospheres —Pressurized apparatus "p"Matériel électrique pour atmosphèresexplosibles —Surpression interne "p"Elektrische Betriebsmittel fürexplosionsgefährdete Bereiche —Überdruckkapselung "p"This European Standard was approved by CENELEC on 1999-10-01. CENELEC members are bound tocomply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving thisEuropean Standard the status of a national standard without any alteration.Up-to-date lists and bibliographical references concerning such national standards may be obtained onapplication to the Central Secretariat or to any CENELEC member.This European Standard exists in three official versions (English, French, German). A version in anyother language made by translation under the responsibility of a CENELEC member into its ownlanguage and notified to the Central Secretariat has the same status as the official versions.CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.
EN 50016:2002- 2 -ForewordThis European Standard was prepared by SC 31-7, Pressurization and other techniques, of the TechnicalCommittee CENELEC TC 31, Electrical apparatus for explosive atmospheres.It consists of the text of EN 50016:1995 and a new amendment (prA1:1999) which was submitted to theformal vote in April 1999 and was approved by CENELEC on 1999-10-01 for publication as a new edition ofthis European Standard.This European Standard supersedes EN 50016:1995.The European Standard was prepared under a mandate given to CENELEC by the European Commissionand the European Free Trade Association and covers essential requirements of the EC Directive 94/9/EC.This European Standard is to be read in conjunction with EN 50014:1997 - Electrical apparatus forpotentially explosive atmospheres — General requirements, and with the European Standards for thespecific types of protection listed in the scope of EN 50014:1997. This European Standard should not beconsidered in conjunction with any editions of these standards and their amendments published before1997.The following dates were fixed:–latest date by which the EN has to be implementedat national level by publication of an identicalnational standard or by endorsement(dop)2003-02-01–latest date by which the national standards conflictingwith the EN have to be withdrawn(dow)2003-06-30Annexes designated “normative” are part of the body of the standard. Annexes designated “informative” aregiven only for information. In this standard annex D is normative and annexes A, B and C are informative._________
- 3 -EN 50016:2002ContentsPage1Scope.42Normative references.43Definitions.5REQUIREMENTS FOR PRESSURIZED ENCLOSURES4Enclosures and ducting.75Temperature limits.96Safety provisions and safety devices (except for static pressurization).97Safety provisions and safety devices for static pressurization.118Supply of protective gas .12ADDITIONAL REQUIREMENTS FOR PRESSURIZED ENCLOSURES WITH CONTAINMENT SYSTEMS9Introduction .1210Release conditions.1211Design requirements for the containment system.1312Protective gas and pressurizing technique.1413Ignition capable apparatus.1614Internal hot surfaces.16VERIFICATION AND TESTS15Type verification and tests.1716Routine tests.21MARKING17Marking .21ANNEXESAnnex A (informative) Ducting of protective gas.23Annex B (informative) Infallibility test for a containment system.28Annex C (informative) Function test of surveillance circuits .29Annex D (normative) Purging and dilution tests.30
EN 50016:2002- 4 -1 Scope1.1This European Standard specifies the requirements for the construction and testing of pressurizedand purged electrical apparatus and “Ex” components forming part of the pressurized apparatus, with typeof protection ‘p’, intended for use in potentially explosive atmospheres of gas vapour and mist.1.2This European Standard supplements EN 50014 in so far as it applies to pressurized and purgedelectrical apparatus with type of protection ‘p’.1.3This European Standard is applicable to electrical equipment and components of Group I CategoryM2 and of Group IIG Category 2 using the technique of pressurize and purge.NOTE In this European Standard, the word “apparatus” has the same meaning as the word “equipment” in Directive 94/9/EC.1.4This European Standard includes the requirements for the construction of the enclosure and itsassociated components, including, if any, the inlet and outlet ducts for the protective gas, and for the safetyprovisions and devices necessary for the type of protection pressurization ‘p’.1.5This European Standard specifies the requirements for pressurized enclosures with or without aninternal source of release, with the exceptions given in 1.7 and 1.8.1.6This European Standard specifies requirements for pressurized enclosures containing an unlimitedsource of release of flammable gas or vapour only where the unlimited source of release is from the surfaceof a liquid.1.7This European Standard does not contain requirements for pressurized rooms or analyser houses (forwhich another standard is in preparation).1.8This European Standard does not contain the requirements for pressurized enclosures where, in acontainment system with limited or unlimited release there is:a) air with an oxygen content greater than normal, orb) oxygen in combination with inert gas in a proportion greater than 21 %.1.9Due to the safety factors incorporated in the type of protection the uncertainty of measurementinherent in good quality, regularly calibrated measurement equipment is considered to have no significantdetrimental effect and need not be taken into account when making the measurements necessary to verifycompliance of the apparatus with the requirements of this standard.2 Normative referencesThis European Standard incorporates, by dated or undated reference, provisions from other publications.These normative references are cited at the appropriate places in the text and the publications are listedhereafter. For dated references, subsequent amendments to or revisions of any of these publications applyto this European Standard only when incorporated in it by amendment or revision. For undated referencesthe latest edition of the publication referred to applies (including amendments).EN 500141997Electrical apparatus for potentially explosive atmospheres — General requirementsA11999A21999EN 50015Electrical Apparatus for potentially explosive atmospheres — Oil immersion ‘o’EN 50017Electrical apparatus for potentially explosive atmospheres — Powder filling ‘q’
- 5 -EN 50016:2002EN 50018Electrical apparatus for potentially explosive atmospheres — Flameproofenclosures ‘d’EN 50019Electrical apparatus for potentially explosive atmospheres — Increased safety ‘e’EN 50020Electrical apparatus for potentially explosive atmospheres — Intrinsic safety ‘i’EN 50028Electrical apparatus for potentially explosive atmospheres — Encapsulation ‘m’EN 50033Electrical apparatus for potentially explosive atmospheres — Caplights for minessusceptible to firedampEN 50039Electrical apparatus for potentially explosive atmospheres — Intrinsically safesystems ‘i’EN 954SeriesSafety of machinery — Safety related parts of control systemsEN 60034-11998Rotating electrical machines — Rating and performance(IEC 60034-1:1996, modified)EN 60034-51986Rotating electrical machines — Part 5: Classification of degrees of protectionprovided by enclosures for rotating machines(IEC 60034-5:1981, modified)EN 605291991Degrees of protection provided by enclosures (IP Code)(IEC 60529:1989)HD 214 S21980Method for determining the comparative and the proof tracking indices of solidinsulating materials under moist conditions(IEC 60112:1979)3 DefinitionsFor the purposes of this European Standard, the definitions of EN 50014 and also the following apply.3.1type of protection pressurization ‘p’technique of applying a protective gas to an enclosure in order to prevent the formation of an explosiveatmosphere inside the enclosure by maintaining an overpressure against the surrounding atmosphere, andwhere necessary by using dilution3.2pressurized enclosureenclosure in which a protective gas is maintained at a pressure greater than that of the external atmosphere3.3protective gasair or inert gas used for purging and maintaining an overpressure and, if required, dilutionNOTE For the purpose of this standard inert gas means nitrogen, carbon dioxide, argon or any gas which, when mixed with oxygen in theratio 4:1 as found in air, does not make the ignition and flammability properties, such as explosive limits, more onerous.
EN 50016:2002- 6 -3.4purgingoperation of passing a quantity of protective gas through the pressurized enclosure and ducts, so that:a) when the protective gas is air, any explosive atmosphere in the pressurized enclosure is reduced to asafe concentration;b) or when the protective gas is inert the concentration of oxygen in the pressurized enclosure is reducedto a safe level3.5static pressurizationmaintenance of an overpressure within a pressurized enclosure without the addition of protective gas in ahazardous area3.6pressurization with leakage compensationmaintenance of an overpressure within a pressurized enclosure so that, when the outlet apertures areclosed, the supply of protective gas is sufficient to compensate for any leakage from the pressurizedenclosure and its ducts3.7pressurization with continuous flow of the protective gasmaintenance of an overpressure within a pressurized enclosure with continuous flow of the protective gasthrough the enclosure3.8internal source of releasepoint or location from which a flammable substance in the form of a flammable gas or vapour or liquid maybe released into the pressurized enclosure such that in the presence of air an explosive gas atmospherecould be formed3.9containment systempart of the apparatus containing the flammable gas, vapour or liquid that may constitute an internal sourceof release3.10infallible containment systemconstruction of an infallible containment system is of such integrity that the possibility of a leak is so remotethat it can be ignored3.11dilutioncontinuous supply of a protective gas, after purging, at such a rate that the concentration of a flammablemixture inside the pressurized enclosure is maintained at a value outside the explosive limits except in adilution areaNOTE Dilution of oxygen by inert gas may result in a concentration of flammable gas above the UEL.3.12ignition capable apparatusapparatus which in normal operation constitutes a source of ignition for a specified explosive atmosphere.This includes electrical apparatus not protected by a type of protection listed in clause 2
- 7 -EN 50016:20023.13dilution areaarea in the vicinity of a source of release where the concentration of flammable gas or vapour is not dilutedto a safe concentration3.14limited releaserelease of flammable gas or vapour the maximum flow rate of which can be predicted3.15unlimited releaserelease of flammable gas or vapour the maximum flow rate of which cannot be predictedNOTE This refers to liquids which can evolve flammable gas or vapour where the rate of release cannot be predicted.3.16lower explosive limit (LEL)volume ratio of flammable gas or vapour in air below which an explosive gas atmosphere will not be formed3.17upper explosive limit (UEL)volume ratio of flammable gas or vapour in air above which an explosive gas atmosphere will not be formed3.18volume ratio (v/v)ratio of the volume of a component to the volume of the gas mixture under specified conditions oftemperature and pressureREQUIREMENTS FOR PRESSURIZED ENCLOSURES4 Enclosures and ducting4.1 GeneralThe pressurized enclosure, including any apertures for moving parts but excluding apertures for the inletand outlet of the protective gas, shall have a degree of protection in accordance with at least IP 40 ofEN 60529, or in the case of a rotating electrical machine, EN 60034-5.NOTE The degree of protection of IP 44 may be required on a coal face under humid and dusty conditions.4.2 Spark and particle barriersThe pressurized enclosure and the ducting, if any, for the protective gas shall guard against the ejection ofignition capable sparks or particles into the hazardous area (see A.2).4.3 Mechanical strengthThe pressurized enclosure, ducts if any, and their connecting parts shall withstand a pressure equal to1,5 times the maximum overpressure specified by the manufacturer for normal service with all outletsclosed with a minimum of 200 Pa.If a pressure can occur in service that can cause a deformation of the enclosure, ducts if any, or connectingparts, a safety device shall be fitted by the manufacturer to limit the maximum internal overpressure to alevel below that which could adversely affect the type of protection.
EN 50016:2002- 8 -4.4 AperturesNOTE The location, size and number of apertures should be suitable for effective purging. The number of apertures should be chosen withregard to the design and disposition of the apparatus, particular consideration being given to the needs of subcompartments into which theapparatus might be divided.4.4.1In the case of static pressurization the enclosure shall have one or more apertures. After filling andpressurization all apertures shall be closed.4.4.2In the case of pressurization with leakage compensation the enclosure shall have one or more inletapertures. It shall also have one or more outlet apertures constructed so that they can be closed afterpurging.4.4.3In the case of pressurization with continuous flow of protective gas, the enclosure shall have one ormore inlet apertures and one or more outlet apertures for the connection of the inlet and outlet ducts for theprotective gas.4.5 MaterialsThe materials used for the enclosure, ducts and connecting parts shall not be adversely affected by thespecified protective gas.4.6 Doors and covers4.6.1Group I apparatus: For Group I pressurized enclosures, doors and covers shall either: have special fasteners complying with 9.2 of EN 50014; or except for the case of static pressurization, be interlocked so that the electrical supply to apparatus notprotected by a type of protection listed in clause 2 of this standard is disconnected automatically whenthey are opened and so that the supply cannot be restored until they are closed. The requirements of 6.6of this standard shall also apply.In the case of static pressurization, doors and covers shall carry the following warning:“Do not open in hazardous area”4.6.2Group II apparatus: The requirements for fasteners for doors and covers in 9.1, paragraph 1, ofEN 50014 need not apply to Group II pressurized enclosures. Doors and covers, except for those which canbe opened only by the use of a tool or key, shall be interlocked so that the electrical supply to electricalapparatus not protected by a type of protection listed in clause 2 of this standard is disconnectedautomatically when they are opened and so that the supply cannot be restored until they are closed. Therequirements of 6.6 of this standard shall also apply.In the case of static pressurization, doors and covers shall only be opened by the use of a tool, and shallcarry the following warning:“Do not open in hazardous area”4.6.3When doors and covers are provided to permit inspection in service, they shall carry the followingwarning:“Do not open when energized”except where provision is made for adjustment during operation, in which case the warning shall be“See instructions before opening”
- 9 -EN 50016:20024.7 Insulating materialsFor Group I apparatus, insulating materials subjected to electrical stresses capable of causing arcs in airand which result from rated currents of more than 16 A shall have a comparative tracking index equal to orgreater than CTI 400M according to IEC 60112.5 Temperature limits5.1The pressurized enclosure shall be classified in accordance with the temperature classificationrequirements of EN 50014.The maximum surface temperature shall be determined either:a) by the temperature of the hottest point of the external surface of the enclosure; orb) by the temperature of the hottest point of the surface of the internal parts which are protected by any ofthe types of protection listed in EN 50014, and which remain energized even when the supply ofprotective gas is removed (e.g. electrical heaters).5.2If during normal service the temperature of any surface within the pressurized enclosure exceeds themaximum value permitted in EN 50014 for the temperature class, appropriate measures shall be taken toprevent, if pressurization ceases, any explosive atmosphere which may exist making contact with thatsurface before it has cooled below the permitted maximum value. This may be achieved either by thedesign and construction of the joints of the pressurized enclosure and ducts or by other means, e.g. bybringing auxiliary ventilation systems into operation or by arranging that the hot surface within the enclosureis in a gas tight or encapsulated housing.When determining the temperature for rotating electrical machines the duty type according to EN 60034-1as specified by the manufacturer shall be considered.6 Safety provisions and safety devices (except for static pressurization)6.1All safety devices used to prevent electrical apparatus protected by pressurization from causing anexplosion shall themselves not be capable of causing an explosion or shall be mounted outside thehazardous area.6.2The safety devices required by this standard form safety related parts of a control system. It is theresponsibility of the manufacturer to assess that the safety and integrity of the control system is consistentwith the level of safety required by this standard.NOTE See also EN 954, Safety of machinery — Safety related parts of a control system.6.3The safety devices shall be provided by the manufacturer of the apparatus or by the user. In the lattercase the apparatus shall be marked “X” and the description documents shall contain all necessaryinformation required by the user to ensure conformity with the requirements of this standard.NOTE An example of the information to be supplied by the manufacturer is given in annex C.6.4Where the safety related control system forms part of the apparatus a functional sequence diagramshall be provided by the manufacturer, for example truth table, state diagram, flow chart, etc., to define theaction of the control system. The sequence diagram shall clearly identify and show the operational states ofthe safety devices and ensuing actions. Functional tests shall be required to verify conformity to thediagram. These tests need only be carried out under normal atmospheric conditions unless otherwisespecified by the manufacturer.
EN 50016:2002- 10 -6.5The manufacturer shall specify the maximum and minimum action levels and tolerances of the safetydevices. The safety devices shall be used within the normal operational limits as specified by themanufacturer taking due account of the most onerous conditions specified for normal service.6.6Safety devices, such as time delay relays and devices for monitoring the flow of protective gas shallbe provided to prevent electrical apparatus within a pressurized enclosure becoming energized until purginghas been completed.The sequence of operations of the safety devices shall be as follows: following the initiation of the sequence, the purging flow through and the overpressure in the enclosureshall be monitored in accordance with this standard; when the minimum flowrate of protective gas is achieved and the overpressure is within the specifiedlimits the purge timer can be started; after the expiry of the time the apparatus is then available to be energized.In the event of failure of any step in the sequence the circuit shall be arranged to reset to the beginning.6.7Where the protective gas is air, the concentration of flammable gas after purging shall not exceed25 % of the LEL.Where the protective gas is other than air, the concentration of oxygen after purging shall not exceed 2 %by volume.The minimum flow rate of protective gas required for purging is the rate specified by the manufacturer andverified by the type tests in 15.3 and 15.4. The minimum purging duration is the duration also specified bythe manufacturer and verified by the type tests. The purging flow rate shall be monitored at the outlet of thepressurized enclosure.NOTE To determine the free space of the associated ducts and to set up the additional purging time for the given minimum flowrate is theresponsibility of the user. The purge duration shall be increased by the time necessary to purge the free volume of those associated ductswhich are not part of the certified apparatus by at least five times their volume at the minimum flow rate specified by the manufacturer.6.8One or more automatic safety devices shall be provided to operate when the overpressure falls belowthe minimum value specified by the manufacturer. It shall be possible to check the correct operation of thesafety devices. Their location and setting shall take into account the requirements of 6.9.When a minimum rate of flow of protective gas is specified by the manufacturer one or more automaticsafety device(s) shall be provided to operate when the flow rate of protective gas at the outlet falls below thespecified minimum value.NOTE The purpose(s) for which the automatic safety device(s) are used (i.e. to disconnect power or to sound an alarm or otherwise ensurethe safety of the installation) is the responsibility of the user.6.9A minimum overpressure of 50 Pa shall be maintained relative to the external pressure at every pointwithin the enclosure and its associated ducts, at which leakage can occur.The manufacturer shall specify the minimum and maximum overpressure in service and the maximumleakage rate at the maximum overpressure.The distribution of pressure in different systems and ducts is illustrated in Figures A.1 to A.4.NOTE It is essential for the safety of an installation of pressurized enclosures that the installation of the associated ducts and of thecompressor or fan does not introduce a hazard. The basic recommendations for the installation of ducting systems are given in annex A.For variable speed motors, consideration must be given to the operational speed range to determine theposition and pressurization of the minimum pressure point within the enclosure.
- 11 -EN 50016:20026.10When a source of protective gas is common to a number of separate enclosures, the safety device ordevices may be common to several of these, provided that the resulting control takes account of the mostunfavourable conditions in the group of enclosures. When a common safety device is fitted, the opening ofa door or cover need not switch off all the electrical apparatus in the enclosures or initiate the alarm,provided that the following three conditions are met:a) the opening of the door or cover is preceded by disconnecting the supply to the electrical apparatus inthe particular pressurized enclosure, except electrical apparatus protected by any of the types ofprotection listed in clause 2 of this standard;b) the common safety device continues to monitor the overpressure in, and where necessary the flowthrough, all the other pressurized enclosures of the group;c) the subsequent connecting of the supply to the electrical apparatus in the particular pressurizedenclosure is preceded by the purging procedure specified in 6.6.6.11Electrical apparatus within the pressurized enclosure that may be energized when type of protectionpressurization ‘p’, is not in operation, shall be protected by a type of protection listed in clause 2 of thisstandard.7 Safety provisions and safety devices for static pressurization7.1All safety devices used to prevent electrical apparatus protected by pressurization from causing anexplosion shall themselves not be capable of causing an explosion or shall be mounted outside thehazardous area.7.2The protective gas shall be inert. The concentration of oxygen after filling with inert gas shall be lessthan 1 % by volume.7.3Internal sources of release of flammable substances are not permitted.7.4The pressurized enclosure shall be filled with inert gas in a non-hazardous area using the procedurespecified by the manufacturer.7.5Two automatic safety devices shall be provided to operate when the overpressure falls below theminimum value specified by the manufacturer. It shall be possible to check the correct operation of thedevices when the apparatus is in service. The automatic safety devices shall only be capable of being resetby the use of a tool or a key.NOTE The purpose for which the automatic safety devices are used (i.e. to disconnect power or to sound an alarm or otherwise ensuresafety of the installation) is the responsibility of the user.7.6Electrical apparatus within the pressurized enclosure that may be energized when type of protectionpressurization ‘p’ is not in operation, shall be protected by a type of protection listed in clause 2 of thisstandard.7.7The minimum level of overpressure shall be greater than the maximum pressure loss in normalservice measured over a period not less than 100 times the time necessary for the cooling of enclosedcomponents according to 6.2 of EN 50014 with a minimum of 1 h. The minimum level of overpressure shallnot be less than 50 Pa above the external pressure under the most onerous conditions specified for normalservice.NOTE If the overpressure falls below the minimum specified, it is the user’s responsibility to ensure that the pressurized enclosure isremoved to a non-hazardous area before refilling.For variable speed motors, consideration must be given to the operational speed range to determine theposition and pressurization of the minimum pressure point within the enclosure.
EN 50016:2002- 12 -8 Supply of protective gas8.1The protective gas shall be non-flammable. The manufacturer shall specify the protective gas andany alternative permitted.NOTE 1 The protective gas should not, by reason of its chemical characteristics or the impurities that it may contain, reduce theeffectiveness of the type of protection pressurization ‘p’, or adversely affect the satisfactory operation and integrity of the enclosed apparatus.NOTE 2 When an inert gas is used and a risk of asphyxiation exists, a suitable warning label should be fixed to the enclosure.Normally the temperature of the protective gas to be taken into consideration is 40C at the inlet to thepressurized enclosure. In special circumstances a higher temperature may be permitted or a lowertemperature may be required, for example for cooling purposes, in which case the maximum inlettemperature of the protective gas shall be marked on the pressurized enclosure and stated in themanufacturer’s documentation.8.2The manufacturer shall specify the density limits of the ra
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