標準編號:	GB/T 3836.8-2021
中文名稱:	爆炸性環境 第8部分：由“n”型保護的設備
英文名稱:	Explosive atmospheres—Part 8: Equipment protection by type of protection “n”
中標分類:	K35    防爆電器
行業分類:	GB    國家標準
ICS分類:	29.260.20 29.260.20    易爆環境用電氣設備 29.260.20
發布機構:	國家市場監督管理總局 國家標準化管理委員會
發布日期:	2021-10-11
實施日期:	2022-5-1
標準狀態:	valid
替代舊標準:	GB 3836.8-2014 爆炸性環境 第8部分: 由n型保護的設備
翻譯語言:	英文
文件格式:	PDF
中文字符數:	27000 字
翻譯價格(元):	1735.0
交付時間:	付款后 1 個工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This document is drafted in accordance with the rules given in the GB/T 1.1-2020 Directives for Standardization — Part 1: Rules for the Structure and Drafting of Standardizing Documents. This part is Part 8 of GB/T 3836 Explosive Atmospheres. The following parts of GB/T 3836 have been published: — Part 1: Equipment — General Requirements; — Part 2: Equipment Protection by Flameproof Enclosures “d”; — Part 3: Equipment Protection by Increased Safety “e”; — Part 4: Equipment Protection by Intrinsic Safety "i"; — Part 5: Equipment Protection by Pressurized Enclosure “p”; — Part 6: Equipment Protection by Oil Immersion “o”; — Part 7: Equipment Protection by Powder Filling “q”; — Part 8: Equipment Protection by Type of Protection “n”; — Part 9: Equipment Protection by Type of Protection “m”; — Part 11: Material Characteristics for Gas and Vapour Classification — Test Methods and Data; — Part 12: Material Characteristics for Combustible Dusts — Test Methods; — Part 13: Equipment Repair, Overhaul and Reclamation; — Part 14: Classification of Areas — Explosive Gas Atmosphere; — Part 15: Electrical Installations Design, Selection and Erection; — Part 16: Electrical Installations Inspection and Maintenance; — Part 17: Equipment Protection by Pressurized Room “p” and Artificially Ventilated Room “v”; — Part 18: Intrinsically Safe Electrical Systems; — Part 20: Equipment with Equipment Protection Level (EPL) Ga; — Part 21: Application of Quality Systems for Equipment Manufacture; — Part 22: Protection of Equipment and Transmission System using Optical Radiation; — Part 23: Group I, Category EPL Ma Equipment Intended to Remain Functional in Atmospheres Endangered by Firedamp and/or Coal Dust — Part 24: Equipment Protection by Special Protection “s”; — Part 25: Requirements for Process Sealing between Flammable Process Fluids and Electrical Systems; — Part 26: Electrostatic Hazards — Guidance; — Part 27: Electrostatic Hazards — Test; — Part 28: Non-electrical Equipment for Potentially Explosive Atmospheres — Basic Method and Requirements; — Part 29: Non-electrical Equipment for Explosive Atmospheres — Constructional Safety “c”, Control of Ignition Source “b”, Liquid Immersion “k; — Part 30: Equipment and Components in Explosive Atmospheres in Underground Mines; — Part 31: Equipment Dust Ignition Protection by Enclosure “t”; — Part 32: Intrinsically Safe Systems with Electronically Controlled Spark Duration Limitation; — Part 33: Equipment in Adverse Service Conditions; — Part 34: Equipment Assemblies; — Part 35: Classification of Areas for Explosive Dust Atmospheres; This standard replaces GB 3836.8-2014 Explosive Atmospheres — Part 8: Equipment Protection by Type of Protection “n” in whole, and the following technical deviations have been made with respect to the GB 3836.8-2014: — The range of internal working voltage is modified (see Clause 1; Clause 1 of Edition 2014); — The non-sparking device “nA” is deleted and transferred to GB/T 3836.3, "ec” (see Clause 3 of Edition 2014); — The enclosed-break device “nC” is deleted and transferred to GB/T 3836.2, "dc” (see Clause 3 of Edition 2014); — The term and definition of hermetically-sealed device “nC” is modified (see Clause 3; Clause 3 of Edition 2014); — The term and definition of normally sparking device is added (see Clause 3); — The provisions of small components are deleted (see 5.2 of Edition 2014); — The requirements for connection facilities and terminal compartments are deleted (see Clause 7 of Edition 2014); — The supplementary requirements for non-sparking electrical rotating machines are deleted (see Clause 8 of Edition 2014); — The supplementary requirements for non-sparking fuses and fuse assemblies are deleted for instrumentation (see Clause 9 of 2014 Edition); — The supplementary requirements for non-sparking plugs and sockets are deleted (see Clause 10 of Edition 2014); — The supplementary requirements for non-sparking luminaires are deleted (see Clause 11 of Edition 2014); — The supplementary requirements for equipment incorporating non-sparking cells and batteries are deleted (see Clause 12 of Edition 2014). — The supplementary requirements for non-sparking low power equipment are deleted (see Clause 13 of Edition 2014); — The supplementary requirements for non-sparking current transformers are deleted (see Clause 14 of Edition 2014); — The requirements for other non-sparking electrical equipment are deleted (see Clause 15 of Edition 2014); — The general supplementary requirements for equipment producing arcs, sparks or hot surfaces are deleted (see Clause 16 of Edition 2014). — The requirements for enclosed-break devices are deleted (see Clause 17 of Edition 2014); — The voltage and current limiting for non-incendive components are added (see 7.2); — The requirements for sealed devices are modified (see Clause 9; Clause 19 of Edition 2014); — The requirements that the COT for device use in a luminaire shall be at least 20 K are deleted (see 19.5 of Edition 2014); — The requirements for in accordance with the relevant industrial standards are added (see 10.2.1); — The requirements for cells and batteries are added (see 10.2.2); — The requirements for cable glands and conduit entries are modified (see 10.2.3; 20.2.2 of Edition 2014); — The requirements for gasketed windows are modified (see 10.2.5.2; 20.2.4.2 of Edition 2014); — The documentation requirements for gasket and seal requirements are added (see 10.2.6); — The requirements for non-resilient seals are modified (see 10.2.7; 20.2.6 of Edition 2014); — The requirements for internal fans with restricted breathing enclosures are added (see 10.2.9); — The type tests for enclosed break devices and non incendive components are deleted (see 22.4 of Edition 2014); — The preparation of non-incendive component samples is added (see 11.1.1); — The requirements for electric strength test are modified (see 12.1; 22.5.2 of Edition 2014); — The type tests of enclosed devices, screws, starters, lamps, ignitors and triggers are deleted (see Clause 22 of Edition 2014); — All tests for batteries are deleted (see 22.11 and 22.12 of Edition 2014); — All tests for electric machines are deleted (22.13 of Edition 2014); — The requirements for routine tests are modified (see Clause 12; Clause 23 of Edition 2014); — The requirements for markings are modified (see Clause 13; Clause 24 of 2014 edition); — The requirements for documentation are modified (see Clause 14; and Clause 25 of Edition 2014); — The requirements for instructions are added (see Clause 15); This document has been redrafted and modified adoption of International Standard IEC 60079-15:2017 Explosive Atmospheres — Part 15: Equipment Protection by Type of Protection “n”. The technical deviations between this document and the International Standard IEC 60079-15:2017, together with their justifications, are given below: — The adjustments on technical deviations have been made for the normative references of this document to adapt to the technical conditions in China, which are mainly reflected in Clause 2 "Normative References”, with the following specific content: ? IEC 60079-0 is replaced by GB/T 3836.1 which is redrafted and modified adoption of the international standard (see Clause 1, etc.); ? IEC 60079-7 is replaced by GB/T 3836.3 which is redrafted and modified adoption of the international standard (see 10.2.2, etc.); — The reference column with IEC 60079-0:2011 (Ed.6.0) in Table 1 of IEC 60079-15:2017 is deleted to be consistent with the Chinese standard version. For the purposes of this document, the following editorial changes have also been made: — In order to be consistent with the current standard series, the name of this document is modified to Explosive Atmospheres — Part 8: Equipment Protection by Type of Protection “n”; — Note 1 in Table 1 regarding standard version information is modified; — The note regarding GB/T 2900.35 is added (see Clause 3); — Bibliography is modified. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights. This document was proposed by China Electrical Equipment Industry Association. This document is under the jurisdiction of National Technical Committee 9 on Explosion Protected Electrical Apparatus of Standardization Administration of China (SAC/TC 9). The previous editions of this document and documents replaced by this document are as follows: — The first edition was issued in 1987 as GB 3836.8-1987, first edition was revised in 2003, and second revision was issued in 2014; — This is the second revised edition. ? Introduction GB/T 3836 Explosive Atmospheres is prepared in order to establish the basic technical requirements for equipment used in explosive atmospheres and its application, covering the design, manufacture, inspection, selection, installation, inspection, maintenance, repair and site classification of equipment used in explosive atmospheres, and adopts the form of partial standards, including but not limited to the following parts: — Part 1: Equipment — General Requirements; — Part 2: Equipment Protection by Flameproof Enclosures “d”; — Part 3: Equipment Protection by Increased Safety “e”; — Part 4: Equipment Protection by Intrinsic Safety "i"; — Part 5: Equipment Protection by Pressurized Enclosure “p”; — Part 6: Equipment Protection by Oil Immersion “o”; — Part 7: Equipment Protection by Powder Filling “q”; — Part 8: Equipment Protection by Type of Protection “n”; — Part 9: Equipment Protection by Type of Protection “m”; — Part 11: Material Characteristics for Gas and Vapour Classification — Test Methods and Data; — Part 12: Material Characteristics for Combustible Dusts — Test Methods; — Part 13: Equipment Repair, Overhaul and Reclamation; — Part 14: Classification of Areas — Explosive Gas Atmosphere; — Part 15: Electrical Installations Design, Selection and Erection; — Part 16: Electrical Installations Inspection and Maintenance; — Part 17: Equipment Protection by Pressurized Room “p” and Artificially Ventilated Room “v”; — Part 18: Intrinsically Safe Electrical Systems; — Part 20: Equipment with Equipment Protection Level (EPL) Ga; — Part 21: Application of Quality Systems for Equipment Manufacture; — Part 22: Protection of Equipment and Transmission System using Optical Radiation; — Part 23: Group I, Category EPL Ma Equipment Intended to Remain Functional in Atmospheres Endangered by Firedamp and/or Coal Dust — Part 24: Equipment Protection by Special Protection “s”; — Part 25: Requirements for Process Sealing between Flammable Process Fluids and Electrical Systems; — Part 26: Electrostatic Hazards — Guidance; — Part 27: Electrostatic Hazards — Test; — Part 28: Non-electrical Equipment for Potentially Explosive Atmospheres — Basic Method and Requirements; — Part 29: Non-electrical Equipment for Explosive Atmospheres — Constructional Safety “c”, Control of Ignition Source “b”, Liquid Immersion “k; — Part 30: Equipment and Components in Explosive Atmospheres in Underground Mines; — Part 31: Equipment Dust Ignition Protection by Enclosure “t”; — Part 32: Intrinsically Safe Systems with Electronically Controlled Spark Duration Limitation; — Part 33: Equipment in Adverse Service Conditions; — Part 34: Equipment Assemblies; — Part 35: Classification of Areas for Explosive Dust Atmospheres; Type of protection “n” is one of the most important explosion-proof types. In terms of standardization of this technology, China formulated GB 3836.8-1987 in 1987, and then revised it twice by IEC 60079-15 in 2003 and 2014. Since the release and implementation of the standard, there has been a certain new development in type of protection “n” explosion-proof technology. In terms of international standards, the current version of the corresponding standard is IEC 60079-15:2017, and its content and structure have been greatly adjusted. The requirements of non-sparking device "nA” and enclosed-break device “nC” have been transferred to other relevant standards, and the main technical content can also be applied to the situation of China. In order to adapt to the development of explosion-proof technology and industry and be consistent with the development of international standards, it is necessary to revise GB 3836.8. Based on the main technical content of IEC 60079-15:2017, appropriate modifications have been made in this revision to adapt to the specific situation in China. This standard is a supplement and modification of GB/T 3836.1 as a specific type of protection part. Explosive Atmospheres — Part 8: Equipment Protection by Type of Protection “n” 1 Scope This document specifies requirements for the construction, testing and marking for Group II electrical equipment with type of protection “n” which includes: sealed devices “nC”, hermetically sealed devices “nC”, non-incendive components “nC” and restricted breathing enclosures “nR” intended for use in explosive gas atmospheres. This document is applicable to electrical equipment where the rated input voltage does not exceed 15 kV r.m.s. AC or DC including where the internal working voltages of the Ex product exceeds 15 kV, for example starters for HID luminaires. This document supplements and modifies the general requirements of GB/T 3836.1, except as indicated in Table 1. Where a requirement of this document conflicts with a requirement of GB/T 3836.1, the requirement of this document will take precedence. Table 1 Relationship of this document to GB/T 3836.1 Clause of GB/T 3836.1 GB/T 3836.1 clause application to this document Clause/Sub-clause number (informative) Clause/Sub-clause title (nominative) Protected sparking “nC” Restricted breathing “nR” 3 Terms and definitions Applies Applies 4 Equipment grouping 4.1 General Excluded Excluded 4.2 Group I Excluded Excluded 4.3 Group II Applies Applies 4.4 Group III Excluded Excluded 4.5 Equipment for a particular explosive atmosphere Applies Applies 5 Temperatures 5.1 Environmental influences Applies Applies 5.2 Service temperature Applies Applies 5.3 Maximum surface temperature 5.3.1 Determination of maximum surface temperature Applies Applies 5.3.2 Limitation of maximum surface temperature 5.3.2.1 Group I electrical equipment Excluded Excluded 5.3.2.2 Group II electrical equipment Applies Applies 5.3.2.3 Group III electrical equipment Excluded Excluded 5.3.3 Small component temperature for Group I and Group II electrical equipment Applies Excluded 5.3.4 Component temperature of smooth surfaces for Group I or Group II electrical equipment Applies Excluded 6 Requirements for all electrical apparatus 6.1 General Applies Applies 6.2 Mechanical strength of equipment Applies Applies 6.3 Opening time of equipment enclosure Excluded Applies 6.4 Circulating currents in enclosures (e.g. of large electrical machines) Applies Applies 6.5 Gasket retention Applies Applies 6.6 Electromagnetic and ultrasonic radiating equipment Applies Applies 7 Non-metallic enclosures or non-metallic parts of enclosures 7.1 General 7.1.1 Applicability Applies Applies 7.1.2 Specification of materials Applies Applies 7.2 Thermal endurance 7.2.1 Tests for thermal resistance Applies Applies 7.2.2 Material selection Applies Applies 7.2.3 Alternative qualification for elastomeric sealing O-rings Applies Applies 7.3 Resistance to ultraviolet light Applies Applies 7.4 Electrostatic charges on external non-metallic materials 7.4.1 Applicability Applies Applies 7.4.2 Avoidance of a build-up of electrostatic charge for Group I or Group II equipment Applies Applies 7.4.3 Avoidance of a build-up of electrostatic charge for Group III equipment Excluded Excluded 7.5 Attached external conductive parts Applies Applies 8 Metallic enclosures and metallic parts of enclosures 8.1 Material composition Applies Applies 8.2 Group I equipment Excluded Excluded 8.3 Group II equipment Applies Applies 8.4 Group III equipment Excluded Excluded 8.5 Copper alloy Applies Applies 9 Fasteners 9.1 General Applies Applies 9.2 Special fasteners Excluded Excluded 9.3 Holes for special fasteners Excluded Excluded 9.4 Hexagon socket set screws Excluded Excluded 10 Interlocking devices Excluded Excluded 11 Insulating bushings Applies Applies 12 (Reserved for future use) Excluded Excluded 13 Ex components Applies Applies 14 Connection facilities Applies Applies 15 Connection facilities for earthing and bonding conductors Applies Applies 16 Entries into enclosures Applies Applies 17 Supplementary requirements for electric machines Excluded Excluded 18 Supplementary requirements for switchgear Excluded 18.1 Flammable dielectric Excluded Applies 18.2 Disconnectors Excluded Applies 18.3 Group I equipment – Provisions for locking Excluded Excluded 1 8.4 Doors and covers Excluded Applies 19 Supplementary requirements for fuses Excluded Excluded 20 Supplementary requirements for plugs and sockets for field wiring connection 20.1 General Applies Applies 20.2 Explosive gas atmospheres Excluded Excluded 20.3 Explosive dust atmospheres Excluded Excluded 20.4 Energized plugs Applies Applies 21 Supplementary requirements for luminaires 21.1 General Applies Applies 21.2 Covers for luminaires of EPL Mb, EPL Gb or EPL Db Excluded Excluded 21.3 Covers for luminaires of EPL Gc or EPL Dc Applies Applies 21.4 Sodium lamps Applies Applies 22 Supplementary requirements for caplights and handlights 22.1 Group I caplights Excluded Excluded 22.2 Group II and Group III caplights and handlights Excluded Applies 23 Equipment incorporating cells and batteries Applies Applies 23.12 Replacement battery pack Applies Applies 24 Documentation Modified Modified 25 Compliance of prototype or sample with documents Applies Applies 26 Type tests Applies Applies 26.4 Tests of enclosures 26.4.1 Order of tests 26.4.1.1 Metallic enclosures, metallic parts of enclosures and glass or ceramic parts of enclosures Applies Applies 26.4.1.2 Non-metallic enclosures or non-metallic parts of enclosures 26.4.1.2.1 General Applies Applies 26.4.1.2.2 Class I equipment Excluded Excluded 26.4.1.2.3 Group II and Group III equipment Applies Applies 26.4.2 Impact resistance test Applies Applies 26.4.3 Drop test Applies Applies 26.4.4 Acceptance criteria Applies Applies 26.4.5 Degrees of protection provide by enclosure (IP) Applies Applies 26.5 Thermal tests 26.5.1 Temperature measurement Applies Applies 26.5.1.1 General Applies Applies 26.5.1.2 Service temperature Applies Applies 26.5.1.3 Maximum surface temperature Applies Applies 26.5.2 Thermal shock test Applies Applies 26.5.3 Small component ignition test (Group I and Group II) Applies Excluded 26.6 Torque test for insulating bushings Applies Applies 26.7 Non-metallic enclosures or non-metallic parts of enclosures 26.7.1 General Applies Applies 26.7.2 test temperature Applies Applies 26.8 Test for thermal endurance to heat Applies Applies 26.9 Test for thermal endurance to cold Applies Applies 26.10 Ultraviolet (UV) resistance test 26.10.1 General Applies Applies 26.10.2 Light exposure Applies Applies 26.10.3 Acceptance criteria Applies Applies 26.11 Test for resistance to chemical agents for Group I electrical equipment Excluded Excluded 26.12 Earth continuity Applies Applies 26.13 Surface resistance test of parts of enclosures of non-metallic materials Applies Applies 26.14 Measurement of capacitance 26.14.1 General Applies Applies 26.14.2 Test procedure Applies Applies 26.15 Verification of ratings of ventilating fans Excluded Excluded 26.16 Alternative qualification of elastomeric sealing O-rings Applies Applies 26.17 Transferred charge test Applies Applies 27 Routine test Applies Applies 28 Manufacturers responsibility Applies Applies 29 Marking 29.1 Applicability Applies Applies 29.2 Location Applies Applies 29.3 General Applies Applies 29.4 Ex marking for explosive gas atmospheres Applies Applies 29.5 Ex marking for explosive dust atmospheres Excluded Excluded 29.6 Combined types (or levels) of protection Applies Applies 29.7 Multiple types of protection Applies Applies 29.8 Ga equipment using two independent Gb types (or levels) of protection Excluded Excluded 29.9 Boundary wall Excluded Excluded 29.10 Ex components Applies Applies 29.11 Small Ex equipment and small Ex components Applies Applies 29.12 Extremely small equipment and extremely small Ex components Applies Applies 29.13 Warning markings Applies Applies 29.14 Battery Applies Applies 29.15 Electrical machines operated with a converter Applies Applies 29.16 Examples of marking Examples Examples 30 Instructions 30.1 General Applies Applies 30.2 Cells and batteries Applies Applies 30.3 Electric machines Excluded Excluded 30.4 Ventilating fans Excluded Excluded 30.5 Cable glands Applies Applies Annex A Supplementary requirements for Ex cable glands Applies Applies Annex B Requirements for Ex components Applies Applies Annex C Example of rig for resistance to impact test Informative annex Informative annex Annex D Motors supplied by converters Informative annex Informative annex Annex E Temperature evaluation of electric machines Informative annex Informative annex Annex F Guideline flowchart for tests of non-metallic enclosures or non-metallic parts of enclosures Informative annex Informative annex Annex G Guidance flowchart for tests of cable glands Informative annex Informative annex Annex H Shaft voltages resulting in motor bearing or shaft brush sparking. Discharge energy calculation Informative annex Informative annex Annex I Special requirements for Group I electrical equipment Excluded Excluded Appendix J Inspection procedure for obtaining Ex certificate Applies Applies Applies: This requirement of GB/T 3836.1 is applied without change. Excluded: This requirement of GB/T 3836.1 does not apply. Modified: This requirement of GB/T 3836.1 is modified as detailed in this document. Note 1: The clause number in the above table is shown for information only. The applicable requirements of GB/T 3836.1 are identified by the clause title which is normative. This document was written against the specific requirements of GB/T 3836.1. Note 2: A shaded row in the above table indicates that this is a clause heading. In cases where the applicability is the same for all of the sub-clauses the ‘Applies’ or ‘Excluded’ is listed in the heading row and the sub-clauses are not expanded. Where the application of the individual sub-clauses may be different, these are expanded in the above table and the applicability for each is listed. Note 3: A non-incendive component is limited in use to the particular circuit for which it has been shown to be non-ignition capable and, therefore, cannot be separately assessed as complying with this document. 2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 3836.1 Explosive Atmospheres — Part 1: Equipment — General Requirements (GB 3836.1-2021, IEC 60079-0:2017, MOD) GB/T 3836.3 Explosive Atmospheres — Part 3: Equipment Protection by Increased Safety “e” (GB/T 3836.3-2021, IEC 60079-7:2015, MOD) 3 Terms and Definitions For the purposes of this document, the terms and definitions given in GB/T 3836.1 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC: http://www.electropedia.org/; — ISO: http://www.iso.org/obp. Note: Additional definitions applicable to explosive atmospheres can be found in GB/T 2900.35. 3.1 devices and components “nC” 3.1.1 hermetically-sealed device “nC” device which is so constructed that it cannot be opened and is sealed effectively by fusion to prevent entry of an external atmosphere 3.1.2 non-incendive component “nC” component having contacts for making or breaking a specified ignition capable circuit but in which the contacting mechanism is designed and constructed so that the component is not capable of causing ignition of the specified explosive gas atmosphere Note: The enclosure of the non-incendive component is not intended to either exclude the explosive gas atmosphere or contain an explosion. This is usually applied to specially constructed switch contacts that are mechanically designed to quench any arc or spark so that they are not a source of ignition. 3.1.3 sealed device “nC” device which is so constructed that it cannot be opened during normal service and is sealed effectively to prevent entry of an external atmosphere 3.2 normally sparking device device with spacings in line with the industrial requirements and which produces arcs and sparks during normal operating conditions Note: Normally sparking devices include switches, relays, and contactors not otherwise Ex protected. 3.3 restricted-breathing enclosure “nR” enclosure that is designed to restrict the entry of gases, vapours and mists 3.4 sealing device device employing a method other than encapsulation to prevent the flow of a gas or a liquid between equipment and a conduit or between separate parts of the equipment by providing sealing facilities Note: This device is not a device covered by GB/T 3836.25. 3.5 separation shortest distance through solid insulating material between two conductive parts 3.6 test port facility to test the integrity of restricted breathing equipment in the field after installation, during initial inspection and during maintenance 3.7 type of protection "n" type "n” type of protection applied to electrical equipment such that, in normal operation and in certain specified regular expected occurrences, it is not capable of igniting a surrounding explosive gas atmosphere Note: Additionally, the requirements of this document are intended to ensure that a malfunction capable of causing ignition is not likely to occur. 4 General 4.1 Equipment grouping and temperature classification Equipment grouping and temperature classification shall be in accordance with the equipment grouping and temperature classification clauses of GB/T 3836.1. 4.2 Potential ignition sources In normal operation and in certain regular expected occurrences specified by this document, the equipment shall not: a) produce an operational arc or spark unless that arc or spark is prevented from causing ignition of a surrounding explosive atmosphere by one of the methods described in Clauses 7 to 10; b) develop a maximum surface temperature in excess of the maximum value appropriate to the temperature class of the equipment, unless the temperature of the surface or hot spot is prevented from causing ignition of a surrounding explosive atmosphere by one of the methods described in Clauses 7 to 10 as appropriate, or is otherwise shown to be safe as specified in Clause 5. 4.3 Equipment requirements Equipment or components which in normal operation produce arcs, sparks or hot surfaces which otherwise would be capable of igniting a surrounding atmosphere shall be protected against causing ignition by one or more of the following methods, all of which provide Equipment Protection Level Gc: a) non-incendive component (see Clause 7); b) hermetically sealed device (see Clause 8); c) sealed device (see Clause 9); d) restricted-breathing enclosure (see Clause 10). 5 Maximum Surface Temperature The maximum surface temperature shall be determined in accordance with the determination of maximum temperature classification requirements of GB/T 3836.1. The surface to be considered shall be the external surface of the equipment including the surface of internal parts of non-incendive components to which the explosive gas atmosphere has access. Note: This is often the outside surface of type of protection “nC” components located within level of protection “ec” equipment. 6 Requirements for Electrical Equipment 6.1 General Electrical equipment with type of protection "n" shall comply with the requirements of this document and the applicable parts of GB/T 3836.1 for the method(s) of protection used. 6.2 Electric strength insulation from earth or frame Where the electrical circuits within the equipment are not connected directly to the frame of the equipment or not intended to be connected to the frame in service, the insulation or separation distance used shall withstand without breakdown one of the following tests:

Foreword II Introduction VIII 1 Scope 2 Normative References 3 Terms and Definitions 4 General 5 Maximum Surface Temperature 6 Requirements for Electrical Equipment 7 Requirements for Non-incendive Components 8 Requirements for Hermetically Sealed Devices 9 Requirements for Sealed Devices 10 Requirements for Restricted-breathing Enclosures 11 Type Test 12 Routine Verifications and Routine Tests 13 Marking 14 Documentation 15 Instructions Bibliography

爆炸性環境 第8部分：由“n”型保護的設備 1 范圍 本文件規定了Ⅱ類爆炸性氣體環境由“n”型保護的電氣設備的結構、試驗和標志的要求。防爆型式包括“nC”密封裝置、“nC”氣密裝置、“nC”非點燃元件和“nR”限制呼吸外殼。 本文件適用于額定輸入電壓不超過15 kV交流有效值或直流的電氣設備，Ex產品內部的工作電壓可以超過15 kV，例如HID燈具的啟動器。 本文件是對GB/T 3836.1通用要求的補充和修改，如表1所示。當本文件的要求與GB/T 3836.1的要求有沖突時，本文件的要求優先。 表1 本文件與GB/T 3836.1的關系 GB/T 3836.1的條款 GB/T 3836.1條款對本文件的適用性 章條號 (資料性) 章條標題 (規范性) 火花保護 “nC” 限制呼吸 “nR” 3 術語和定義 適用 適用 4 設備分類 4.1 總則 排除 排除 4.2 I類 排除 排除 4.3 Ⅱ類 適用 適用 4.4 Ⅲ類 排除 排除 4.5 特定爆炸性氣體環境用設備 適用 適用 5 溫度 5.1 環境影響 適用 適用 5.2 工作溫度 適用 適用 5.3 最高表面溫度 5.3.1 最高表面溫度的測定 適用 適用 5.3.2 最高表面溫度的限制 5.3.2.1 I類電氣設備 排除 排除 5.3.2.2 Ⅱ類電氣設備 適用 適用 5.3.2.3 Ⅲ類電氣設備 排除 排除 5.3.3 I類或Ⅱ類電氣設備的小元件溫度 適用 排除 5.3.4 I類或Ⅱ類電氣設備光滑表面的元件溫度 適用 排除 6 對所有設備的要求 6.1 總則 適用 適用 6.2 設備的機械強度 適用 適用 6.3 設備外殼打開時間 排除 適用 6.4 外殼中的環流(如大型電機) 適用 適用 6.5 襯墊保持 適用 適用 6.6 電磁能和超聲波能輻射設備 適用 適用 7 非金屬外殼和外殼的非金屬部件 7.1 通則 7.1.1 適用范圍 適用 適用 7.1.2 材料要求 適用 適用 7.2 熱穩定性 7.2.1 熱穩定性試驗 適用 適用 7.2.2 材料選擇 適用 適用 7.2.3 O形彈性密封圈替換 適用 適用 7.3 耐紫外線 適用 適用 7.4 外部非金屬材料上的靜電電荷 7.4.1 適用性 適用 適用 7.4.2 避免靜電電荷在I類或Ⅱ類設備上積聚 適用 適用 7.4.3 避免靜電電荷在Ⅲ類設備上積聚 排除 排除 7.5 附屬外部導電部件 適用 適用 8 金屬外殼和外殼的金屬部件 8.1 材料成分 適用 適用 8.2 I類設備 排除 排除 8.3 Ⅱ類設備 適用 適用 8.4 Ⅲ類設備 排除 排除 8.5 銅合金 適用 適用 9 緊固件 9.1 通則 適用 適用 9.2 特殊緊固件 排除 排除 9.3 特殊緊固件的孔 排除 排除 9.4 內六角緊定螺釘 排除 排除 10 聯鎖裝置 排除 排除 11 絕緣套管 適用 適用 12 (預留將來使用) 排除 排除 13 Ex元件 適用 適用 14 連接件 適用 適用 15 接地導體或等電位導體連接件 適用 適用 1 6 外殼的引入裝置 適用 適用 17 電機的補充要求 排除 排除 18 開關的補充要求 排除 18.1 可燃性絕緣介質 排除 適用 18.2 隔離開關 排除 適用 18.3 I類設備——聯鎖措施 排除 排除 1 8.4 門和蓋 排除 適用 19 熔斷器的補充要求 排除 排除 20 現場布線連接用外部插頭、插座和連接器的補充要求 20.1 通則 適用 適用 20.2 爆炸性氣體環境 排除 排除 20.3 爆炸性粉塵環境 排除 排除 20.4 帶電插頭 適用 適用 21 燈具的補充要求 21.1 通則 適用 適用 21.2 EPL Mb、EPL Gb或EPL Db級燈蓋 排除 排除 21.3 EPL Gc或EPL Dc級燈蓋 適用 適用 21.4 鈉燈 適用 適用 22 帽燈和手提燈的補充要求 22.1 I類帽燈 排除 排除 22.2 Ⅱ類和Ⅲ類帽燈和手提燈 排除 適用 23 裝有電池的設備 適用 適用 23.12 可更換電池包 適用 適用 24 文件 修改 修改 25 試樣或樣機與文件的一致性 適用 適用 26 型式試驗 適用 適用 26.4 外殼試驗 26.4.1 試驗順序 26.4.1.1 金屬外殼、外殼的金屬部件和外殼的玻璃或陶瓷部件 適用 適用 26.4.1.2 非金屬外殼或外殼的非金屬部件 26.4.1.2.1 通則 適用 適用 26.4.1.2.2 I類設備 排除 排除 26.4.1.2.3 II類和Ⅲ類設備 適用 適用 26.4.2 抗沖擊試驗 適用 適用 26.4.3 跌落試驗 適用 適用 26.4.4 合格判據 適用 適用 26.4.5 外殼防護等級(IP) 適用 適用 26.5 熱試驗 26.5.1 溫度測定 適用 適用 26.5.1.1 通則 適用 適用 26.5.1.2 工作溫度 適用 適用 26.5.1.3 最高表面溫度 適用 適用 26.5.2 熱劇變試驗 適用 適用 26.5.3 小元件點燃試驗(I類和Ⅱ類) 適用 排除 26.6 絕緣套管扭轉試驗 適用 適用 26.7 非金屬外殼和外殼的非金屬部件 26.7.1 通則 適用 適用 26.7.2 試驗時的溫度 適用 適用 26.8 耐熱試驗 適用 適用 26.9 耐寒試驗 適用 適用 26.10 耐紫外線(UV)試驗 26.10.1 通則 適用 適用 26.10.2 光暴露 適用 適用 26.10.3 合格判據 適用 適用 26.11 I類設備的耐化學試劑試驗 排除 排除 26.12 接地連續性 適用 適用 26.13 非金屬材料外殼部件的表面電阻測定 適用 適用 26.14 電容測量 26.14.1 通則 適用 適用 26.14.2 試驗程序 適用 適用 26.15 風扇額定值驗證 排除 排除 26.16 O形彈性密封圈替換評定 適用 適用 26.17 轉移電荷試驗 適用 適用 27 例行試驗 適用 適用 28 制造商責任 適用 適用 29 標志 29.1 適用性 適用 適用 29.2 標志位置 適用 適用 29.3 通則 適用 適用 29.4 爆炸性氣體環境防爆標志 適用 適用 29.5 爆炸性粉塵環境防爆標志 排除 排除 29.6 混(復)合型防爆型式 適用 適用 29.7 多種防爆型式 適用 適用 29.8 使用兩個獨立Gb級防爆型式(保護等級)的Ga級設備 排除 排除 29.9 邊界墻 排除 排除 29.10 Ex元件 適用 適用 29.11 小型Ex設備和Ex元件 適用 適用 29.12 超小型Ex設備和Ex元件 適用 適用 29.13 警告標志 適用 適用 29.14 電池 適用 適用 29.15 由變頻器控制的電機 適用 適用 29.16 標志示例 示例 示例 30 使用說明書 30.1 通則 適用 適用 30.2 電池說明書 適用 適用 30.3 電機說明書 排除 排除 30.4 通風扇說明書 排除 排除 30.5 電纜引入裝置說明書 適用 適用 附錄A 電纜引入裝置的附加要求 適用 適用 附錄B 對Ex元件的要求 適用 適用 附錄C 抗沖擊試驗裝置示例 資料性附錄 資料性附錄 附錄D 連接到變頻器的電機 資料性附錄 資料性附錄 附錄E 電機溫升評估 資料性附錄 資料性附錄 附錄F 非金屬外殼或外殼的非金屬部件試驗的指導流程圖 資料性附錄 資料性附錄 附錄G 電纜引入裝置試驗的指導流程圖 資料性附錄 資料性附錄 附錄H 軸電壓導致電機軸承或電刷火花放電能量計算 資料性附錄 資料性附錄 附錄I I類電氣設備的特殊要求 排除 排除 附錄J 取得防爆合格證的檢驗程序 適用 適用 “適用”：GB/T 3836.1的要求適用，沒有修改。 “排除”：GB/T 3836.1的要求不適用。 “修改”：GB/T 3836.1的要求在本文件有修改。 注1：表中的章條號僅作為信息。GB/T 3836.1適用的要求由章條標題確定，屬于規范性內容。本文件按照GB/T 3836.1—9021的具體要求編寫。 注2：表中的陰影行表示標題。在標題欄里的“適用”或“排除”適用于所有子條款，而且子條款不再擴展。個別子條款的適用性與標題欄不相同時，在表格中列出每條適用與否。 注3：非點燃元件限定只能用在已經表明不能點燃的特定電路中，因此不單獨按照本文件的要求評定。 2規范性引用文件 下列文件中的內容通過文中的規范性引用而構成本文件必不可少的條款。其中，注日期的引用文件，僅該日期對應的版本適用于本文件；不注日期的引用文件，其最新版本(包括所有的修改單)適用于本文件。 GB/T 3836.1 爆炸性環境 第1部分：設備 通用要求(GB/T 3836.1—2021，IEC 60079—0：2017，MOD) GB/T 3836.3 爆炸性環境 第3部分：由增安型“e”保護的設備(GB/T 3836.3—2021，IEC 60079—7：2015，MOD) 3術語和定義 GB/T 3836.1界定的以及下列術語和定義適用于本文件。 ISO和IEC在以下地址維護用于標準化的術語數據庫： ——IEC：http：//www.electropedia.org/； ——ISO：http：//www.iso.org/obp。 注：適用于爆炸性環境的其他定義見GB/T 2900.35。 3.1 “nC”裝置和元件devices and components “nC” 3.1.1 “nC”氣密裝置hermetically-sealed device “nC” 結構上使其不能打開，并且通過熔接有效地密封阻止外部大氣進入的裝置。 3.1.2 “nC”非點燃元件non—incendive component “nC” 接通或斷開具有規定的點燃能力的電路的觸頭，但是接觸機構的設計和結構使其不能夠點燃規定的爆炸性氣體環境的元件。 注：非點燃元件的外殼不用于阻止爆炸性氣體環境或承受爆炸。通常適用于特殊結構的開關觸點.這些開關觸點的機械設計能夠熄滅電弧或火花，使它們不會成為點燃源。 3.1.3 “nC”密封裝置 sealed device “nC” 結構上使其在正常運行期間不能打開，并且有效地密封阻止外部大氣進入的裝置。 3.2 普通火花裝置normally sparking device 在正常運行條件下產生電弧和火花，電氣間隙和爬電距離是符合工業要求的裝置。 注：普通火花裝置包括未采用防爆保護的開關、繼電器和接觸器。 3.3 “nR”限制呼吸外殼restricted-breathing enclosure “nR” 設計成能限制氣體、蒸氣和薄霧進入的一種外殼。 3.4 密封裝置sealing device 不用澆封面采用密封件，阻止氣體或液體在設備和導管之間或設備的不同部件之間流動的裝置。 注：該裝置不是GB/T 3836.25包括的裝置。 3.5 間距 separation 兩導電部件之間通過固體絕緣材料的最短距離。 3.6 測試接口test port 安裝后，在初始檢查和維護期間，在現場測試限制呼吸設備完整性的裝置。 3.7 防爆型式“n” type of protection “n” “n”型 電氣設備的一種防爆型式，采用該型式的電氣設備，在正常運行時和本文件規定的一些常規預期條件下，不能點燃周圍的爆炸性氣體環境。 注：本文件的要求用于確保不出現能引起點燃的故障。 4 通則 4.1 設備類別和溫度組別 設備類別和溫度組別應符合GB/T 3836.1設備類別和溫度組別的規定。 4.2潛在點燃源 設備在正常運行和本義件規定的一些常規預期條件下應： a) 不能產生操作電弧或火花，除非按第7～10章所述的方法之一來防止其點燃周圍的爆炸性環境； b)不能產生超過設備溫度組別所對應的最高表面溫度，除非按第7～10章所述的方法之一來防止表面溫度或最熱點的溫度點燃周圍的爆炸性環境，或者按第5章的規定證明是安全的。 4.3 設備要求 在正常運行中，有能力點燃周圍環境的電弧、火花或熱表面的設備或元件應采用下列一種或多種方法防止點燃(這些方法提供設備保護級別Gc)： a)非點燃元件(見第7章)； b)氣密裝置(見第8章)； c)密封裝置(見第9章)； d)限制呼吸外殼(見第10章)。 5最高表面溫度 應按照GB/T 3836.1確定最高表面溫度的要求來確定最高表面溫度。考慮的表面應是設備的外表面，也包括爆炸性氣體環境有可能進入的非點燃元件的內部部件的表面。 注：這可能是位于“cc”級設備內部的“nC”元件的外表面。 6對電氣設備的規定 6.1 通則 “n”型保護電氣設備應符合本文件的要求和GB/T 3836.1適用部分的要求。 6.2 對地或機架絕緣的電氣強度 如果設備中的電路不直接連接到設備機架上，或者在設備運行時不連接到機架上，則所用的絕緣或間距應能承受下列試驗： a) 電氣設備各部件的有關工業標準規定的試驗。或 b)如果上述試驗要求不存在，至少試驗電壓應按下列1)或2)要求，歷時至少1 min不擊穿。 1) 對于設備供電電壓峰值不超過90 V或設備內部峰值電壓不超過90 V的電氣設備，試驗電壓的有效值為500 V(相對誤差0％～5％)； 2) 對于其他電氣設備，或設備內部電壓峰值超過90 V，試驗電壓的有效值為2 U+1 000 V(相對誤差0％～5％)或有效值1 500 V(相對誤差0％～5％)，取二者之中較大值。 允許用直流試驗電壓代替規定的交流試驗電壓，對于絕緣繞組應為規定的交流試驗電壓有效值的170％，或者對于在絕緣介質中的電氣間隙或爬電距離，應為規定的交流試驗電壓有效值的140％。 注：U是額定供電電壓或者設備內部出現的最高電壓中的較高值。 對于具有電隔離部件的設備，應在適當的電壓下對各部件分別施加試驗電壓。 7非點燃元件的要求 7.1 型式試驗 非點燃元件應進行11.1規定的型式試驗。 7.2 電路限制 非點燃元件的最大額定值應限制在254 V和16 A交流有效值或直流。 注：非點燃元件觸頭的布置熄滅了初始火焰，因此不會點燃外部的爆炸性環境。非點燃元件限定用于與元件在試驗時構成的電路或危險更小的電路具有相同電氣特性值的電路中，例如電壓、電流、電感、電容、沖擊電流或過載條件。 8氣密裝置的要求 氣密裝置是由金屬與金屬或玻璃熔合而成的，符合密封裝置的要求，不需要試驗。 外殼應能承受正常的操作和組裝作業而不損壞密封。 9密封裝置的要求 9.1非金屬材料 當密封裝置不構成防爆設備外殼的一部分時，應按照11.2進行試驗。當設備由一個獨立的腔體和基座密封在一起時，腔體和基座不認為是密封的一部分。 按照GB/T 3836.1的要求，資料應包括密封裝置制造商提供的數據表或者聲明，以證明用于密封的材料滿足將要承受的工作溫度范圍。用于密封的材料連續運行溫度(COT)范圍，下限應低于或等于最低工作溫度并且上限比最高工作溫度至少高10 K。該數據表或者聲明，可以是密封或澆封材料，也可以是整個密封裝置。當密封裝置構成防爆設備外殼的一部分或全部時，GB/T 3836.1的要求適用。 9.2 開啟 密封裝置的結構在正常運行時應不能開啟。 9.3 內部空間 密封裝置的內部凈容積應不超過100 cm3，并且必要時應設置外部連接件，例如引出線或外接端子。 9.4 操作 外殼應能承受正常的操作和組裝作業而不損壞。 9.5襯墊和密封 襯墊和密封，包括灌封密封，安裝位置應能使其在正常運行條件下不受機械損傷，并能在裝置的預期壽命期間保持密封性能。 9.6型式試驗 應進行11.2規定的型式試驗。 10 限制呼吸外殼的要求 10.1 通則 限制呼吸設備應限制耗散功率，使測定的外部溫度不超過GB/T 3836.1規定的最高表面溫度。 限制呼吸外殼僅應以完整的設備來進行評價，包括全部配件和附件。 或者設備應配有引入裝置，或者在“nR”設備的說明書中明確引入裝置的選擇信息。 10.2 結構要求 10.2.1 設備類型 10.2.1.1 裝有普通火花裝置的設備 裝有普通電弧或火花裝置的限制呼吸設備，或者有頻繁溫度循環的熱表面的設備，應限制耗散功率，使在正常運行時外殼外部測得的溫度不會高于環境溫度20 K。