1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULNational Differences ForUL 60079-2Explosive Atmospheres Part 2: Equipment Protection by Pressurized Enclosure pUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHO
2、UT PERMISSION FROM ULNational Differences ForUL 60079-2Explosive Atmospheres Part 2: Equipment Protection by Pressurized Enclosure pSixth EditionEdition Date: JUNE 2, 2017UL 60079-2 is an adoption of IEC 60079-2, Explosive Atmospheres - Part 2: Equipment Protectionby Pressurized Enclosure p (Edition
3、 6, issued by IEC July, 2014). Please note that the nationaldifference document incorporates all of the U.S. national differences for UL 60079-2.This document provides a single listing of the National Differences included in the UL adoption ofthe corresponding IEC standard.All rights reserved. No pa
4、rt of this publication may be reproduced, stored in a retrieval system, ortransmitted in any form by any means, electronic, mechanical photocopying, recording, or otherwisewithout prior permission of UL.UL provides this standards document as is without warranty of any kind, either expressed or impli
5、ed,including but not limited to, the implied warranties of merchantability or fitness for any purpose.In no event will UL be liable for any special, incidental, consequential, indirect or similar damages,including loss of profits, lost savings, loss of data, or any other damages arising out of the u
6、se of or theinability to use this standards document, even if UL or an authorized UL representative has been advisedof the possibility of such damage. In no event shall ULs liability for any damage ever exceed the pricepaid for this standards document, regardless of the form of the claim.Users of th
7、e electronic versions of ULs Standards for Safety agree to defend, indemnify, and hold ULharmless from and against any loss, expense, liability, damage, claim, or judgment (including reasonableattorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronicSt
8、andard on the purchasers computer system.Copyright 2017 Underwriters Laboratories Inc.JUNE 2, 2017NATIONAL DIFFERENCES FOR UL 60079-22UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULPrefaceThis document provides a single listing of the technic
9、al National Differences included in the UL adoptionof the corresponding IEC standard.In its IEC-based standards, UL uses the notations indicated below to identify national difference type, andthese types are additionally noted in this document. The standard may not use all types of thesedeviations.D
10、1 - These are deviations which are based on basic safety principles and requirements, elimination ofwhich would compromise safety for U.S. consumers and users of products.D2 - These are deviations based on safety practices. These are deviations for IEC requirements that maybe acceptable, but adoptin
11、g the IEC requirements would require considerable retesting or redesign on themanufacturers part.DC - These are deviations based on the component standards and will not be deleted until a particularcomponent standard is harmonized with the IEC component standard.DE - These are deviations based on ed
12、itorial comments or corrections.DR - These are deviations based on the national regulatory requirements.Each national difference contains a description of what the national difference entails. Typically one of thefollowing words is used to explain how the text of the national difference is to be app
13、lied to the base IECtext:Addition / Add - An addition entails adding a complete new numbered clause, subclause, table, figure,or annex. Addition is not meant to include adding select words to the base IEC text.Deletion / Delete - A deletion entails complete deletion of an entire numbered clause, sub
14、clause, table,figure, or annex without any replacement text.Modification / Modify - A modification is an altering of the existing base IEC text such as the addition,replacement or deletion of certain words or the replacement of an entire clause, subclause, table, figure,or annex of the base IEC text
15、.JUNE 2, 2017 NATIONAL DIFFERENCES FOR UL 60079-2 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULNational Differences1DV DR Modification of Clause 1 to replace with the following:This part of IEC 60079 standard contains the specific requirem
16、ents for the constructionand testing of electrical equipment with pressurized enclosures, of type of protection “p”,intended for use in explosive gas atmospheres or explosive dust atmospheres. It alsoincludes the requirements for pressurized enclosures containing a limited release of aflammable subs
17、tance.This standard supplements and modifies the general requirements of IEC 60079-0 UL60079-0. Where a requirement of this standard conflicts with a requirement of IEC 60079-0UL 60079-0, the requirements of this standard take precedence.This standard does not include the requirements for:pressurize
18、d enclosures where the containment system may releasea) air with an oxygen content greater than normal, orb) oxygen in combination with inert gas where the oxygen is in a proportiongreater than 21 %.pressurized rooms or analyser houses; see IEC 60079-13;pressurized enclosures used where “explosives”
19、 or pyrotechnics are present;pressurized enclosures used where hybrid mixtures of gas/vapour and combustible dustare present;pressurized enclosures used where pyrophoric substances such as explosives orpropellants containing their own oxidizers are presentpressurized enclosures with an internal sour
20、ce of release of combustible dust.NOTE When the user acts in the role of the manufacturer, it is typically the users responsibility to ensure that allrelevant parts of this standard are applied to the manufacturing and testing of the equipment.Where references are made to other IEC 60079 standards,
21、the reference requirementsfound in these standards apply as modified by any applicable U.S. National Differences.2DV DR Modification of Clause 2 references to replace with the following:IEC 60034-5, Rotating electrical machines Part 5: Degrees of protection provided by the integraldesign of rotating
22、 electrical machines (IP code) ClassificationIEC 60050 (all parts), International Electrotechnical VocabularyIEC 60079-0, Explosive atmospheres Part 0: Equipment General requirementsJUNE 2, 2017NATIONAL DIFFERENCES FOR UL 60079-24UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDIST
23、RIBUTION WITHOUT PERMISSION FROM ULIEC 60079-11, Explosive atmospheres Part 11: Equipment protection by intrinsic safety iIEC 60079-15, Explosive atmospheres Part 15: Equipment protection by type of protection nIEC 60112, Method for the determination of the proof and the comparative tracking indices
24、 of solidinsulating materialsIEC 60127, (All parts) Miniature fusesIEC 60529, Degrees of protection provided by enclosures (IP Code)IEC 60664-1, Insulation coordination for equipment within low-voltage systems Part 1:Principles, requirements and testsUL 60079-0 Explosive atmospheres Part 0: Equipmen
25、t General requirementsUL 60079-11 Explosive atmospheres Part 11: Equipment protection by intrinsic safety iUL 60079-15 Explosive atmospheres Part 15: Equipment protection by type of protection n5.4DV.1 DE Modification of Clause 5.4, second paragraph to replace with the following5.4DV.1.1 If a pressu
26、re can occur in service that can cause a deformation of the enclosure,ducts if any, or connecting parts, a safety device shall be fitted to limit the maximuminternal overpressure to a level below that which could adversely affect the type ofprotection. If the manufacturer does not provide the safety
27、 device, the certificate numbershall include the X suffix in accordance with the marking requirements of IEC 60079-0and the Specific Conditions of Use listed on the certificate in accordance with UL 60079-0shall detail the necessary information required by the user to ensure conformity with therequi
28、rements of this standard.5.5.2DV D2 Modification of Clause 5.5.2 to replace with the following:Vents providing not less than 1 cm2of vent area for each 1 000 cm3, with a minimum ventsize of 6,3 mm diameter are typically sufficient for adequate purging. Other geometries andarrangements that meet the
29、basic requirements are also sufficient.NOTE Non-circular vents or perforated hole arrangements that result in the same area and freedom of gasmovement would typically meet this requirement.5.9DV.1 DE Modification of Clause 5.9, fifth paragraph to replace with the following5.9DV.1.1 If the manufactur
30、er does not provide the spark and particle barriers, thecertificate number shall include the X suffix in accordance with the marking requirementsof IEC 60079-0 and the Specific Conditions of Use listed on the certificate in accordancewith UL 60079-0 shall detail the necessary information required by
31、 the user to ensureconformity with the requirements of this standard.JUNE 2, 2017 NATIONAL DIFFERENCES FOR UL 60079-2 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL6.2DV DR Modification of Clause 6.2 to replace with the following:The temper
32、ature class shall be based on the higher of the following temperatures:a) the hottest external surface of the enclosure; orb) the hottest internal component surface.Exception: An internal component may exceed the marked temperature class ifi) it complies with the relevant “small component” requireme
33、nts of IEC UL60079-0, orii) the pressurized enclosure is Level of Protection “pxb” and complies with therequirements for opening times in IEC UL 60079-0. Appropriate measures shall betaken to prevent, if pressurization ceases, any explosive gas atmosphere whichmay exist making contact with the hot c
34、omponent surface before it has cooledbelow the permitted maximum value.This may be achieved either by the design and construction of the joints of the pressurizedenclosure and ducts or by other means, for example, by bringing auxiliary ventilationsystems into operation or by arranging that the hot s
35、urface within the pressurizedenclosure is in a gas-tight or encapsulated housing.NOTE Examples of “appropriate measures” include but are not limited to the design and construction of the jointsof the pressurized enclosure and ducts or by bringing auxiliary ventilation systems into operation or by pl
36、acingthe hot surface within the pressurized enclosure in a gas-tight or encapsulated housing.For Level of Protection “pyb”, hot ignition-capable parts in normal operation are notpermitted within the enclosure.7.1DV DE Modification of Clause 7.1 to replace with the following:All safety devices used t
37、o reduce the likelihood of electrical equipment protected bypressurization from causing ignition shall themselves not be capable of causing ignition(see 7.15) or shall be mounted outside the hazardous area.7.3DV DE Modification of Clause 7.3, to replace with the following:The safety devices shall be
38、 provided by the manufacturer of the equipment or by the user.If the manufacturer does not provide the safety devices, the certificate number shallinclude the X suffix in accordance with the marking requirements of IEC 60079-0 and theSpecific Conditions of Use listed on the certificate in accordance
39、 with UL 60079-0 shalldetail the necessary information required by the user to ensure conformity with therequirements of this standard.7.4.1DV.1 DE Modification of Clause 7.4.1, second paragraph to replace with thefollowing:7.4.1DV.1.1 If a vent is provided, it shall comply with the applicable requi
40、rements in Table2 have a spark and particle barrier.JUNE 2, 2017NATIONAL DIFFERENCES FOR UL 60079-26UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7.4.2DV.1 DE Modification of Clause 7.4.2 to add the following after the secondparagraph:7.4.2D
41、V.1.1 If a vent is provided, it shall comply with the requirements in Table 2.7.4.3DV.1 DE Modification of Clause 7.4.3 to add the following after the secondparagraph:7.4.3DV.1.1 If a vent is provided, it shall comply with the requirements in Table 2.7.11DV.1 DE Modification of Clause 7.11, first pa
42、ragraph (item 9 of d) to delete text, itdoes not apply:9) the exclusion for non-metallic enclosures and non-metallic parts of enclosures in 5.1has not been applied;11.1.2DV.1 DE Modification of Clause 11.1.1, second paragraph to replace with thefollowing:11.1.2DV.1.1 The certificate number shall inc
43、lude the X suffix in accordance with themarking requirements of IEC 60079-0 and the Specific Conditions of Use listed on thecertificate in accordance with UL 60079-0 shall detail the necessary information requiredby the user to ensure safe use.12.3DV.1 DE Modification of Clause 12.3, fourth paragrap
44、h to replace with the following:12.3DV.1.1 If the flow limiting device is not included as part of the equipment, thecertificate number shall include the X suffix in accordance with the marking requirementsof IEC 60079-0 and the Specific Conditions of Use listed on the certificate in accordancewith U
45、L 60079-0 shall detail the necessary information required by the user to ensureconformity with the requirements of this standard including the maximum pressure andflow of the flammable substance into the containment system.18.3DV.1 DE Modification of Clause 18.3, item a) to include permissible subst
46、itutemarking for the level of protection marking for Group III with the following:JUNE 2, 2017 NATIONAL DIFFERENCES FOR UL 60079-2 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL60079-2 level of protection EPL Permissible substituteproduct m
47、arkingAdded zone marking“pxb” Db “pb” 21“pyb” Db “pb” 21“pzc” Dc “p” 22NOTE 1 The 2017, and prior, National Electrical Code, NFPA 70, does not recognize “pxb”, “pyb” and “pzc” asa Type of Protection for Zones 21 and 22. Product marking “pb” and “p” are substituted until this can be rectified.Example
48、 markings: Zone 21 AEx pb IIIC T70 C Db, Zone 22 AEx p IIIC T70 C Dc.NOTE 2 This standard does not prohibit the use of a second EX marking string including the permissiblesubstitute marking as appropriate. For example:Zone 21 AEx pxb IIIC T70 C DbZone 21 AEx pb IIIC T70 C DborZone 22 AEx pzc IIIC T7
49、0 C DcZone 22 AEx p IIIC T70 C Dc18.6DV.1 DE Modification of Clause 18.6, NOTES to replace with the following:NOTE Markings “p” and “Ex p” do not appear in IEC 60079-0 UL 60079-0, Ed. 6 or earlier.NOTE Markings “p” and “Ex p” do not appear in NEC 2017 and prior, National Electrical Code, NFPA 70.Annex G.2.2DV.1 DE Modification of Clause G.2.2, second paragraph to replace with thefollowing:G.2.2DV.1.1 Protective Components shall conform to the following requirements. Themanufacturers technical literature is suf
