Standard No.:	GB/T 3836.15-2017
English Name:	Explosive atmospheres—Part 15: Electrical installations design, selection and erection
Chinese Name:	爆炸性环境 第15部分：电气装置的设计、选型和安装
Professional Classification:	GB    National Standard
Issued by:	AQSIQ AND SAC
Issued on:	2017-12-29
Implemented on:	2018-7-1
Status:	valid
Superseding:	GB 3836.15-2000 Electrical apparatus for explosive gas atmospheres--Part 15:Electrical installations in hazardous areas(other than mines) GB 12476.2-2010 Electrical apparatus for use in the presence of combustible dust—Part 2:Selection and installation
Language:	English
File Format:	PDF
Word Count:	35000 words
Price(USD):	870.0
Delivery:	via email in 1 business day

1 Scope This part of “Explosive Atmosphere” contains the specific requirements for the design, selection and erection of electrical installations in hazardous areas associated with explosive atmospheres. Where the equipment is required to meet other environmental conditions, for example, protection against ingress of water and resistance to corrosion, additional methods of protection may be necessary. The method used shall not adversely affect the integrity of the enclosure. The requirements of this standard apply only to the use of equipment under normal or near normal atmospheric conditions. For other conditions, additional precautions may be necessary. For example, most flammable materials and many materials which are normally regarded as non-flammable might burn vigorously under conditions of oxygen enrichment. Other precautions might also be necessary in the use of equipment under conditions of extreme temperature and pressure. Such precautions are beyond the scope of this part. These requirements are in addition to the requirements for installations in non-hazardous areas. This part applies to all electrical equipment including fixed, portable, transportable and personal, and installations, permanent or temporary. It applies to installations at all voltages. This part does not apply to: —— electrical installations in mines susceptible to firedamp; Note: This part may apply to electrical installations in mines where explosive gas atmospheres other than firedamp may be formed and to electrical installations in the surface installation of mines. —— inherently explosive situations and dust from explosives or pyrophoric substances (for example explosives manufacturing and processing); —— rooms used for medical purposes; —— electrical installations in areas where the hazard is due to hybrid mixtures of combustible dust and explosive gas, vapour or mist. This part does not take into account of any risk due to an emission of flammable or toxic gas from the dust. 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 755 Rotating Electrical Machines - Rating and Performance (GB/T 755-2008, IEC 60034-1: 2004, IDT) GB/T 1408.1 Insulating Materials - Test Methods for Electric Strength - Part 1: Test at Power Frequencies (GB/T 1408.1-2006, IEC 60243-1: 1998, IDT) GB 3836.1-2010 Explosive Atmospheres – Part 1: Equipment - General Requirements (IEC 60079-0: 2007, MOD) GB 3836.2-2010 Explosive Atmospheres - Part 2: Equipment Protection by Flameproof Enclosures “d” (IEC 60079-1: 2007, MOD) GB 3836.3-2010 Explosive Atmospheres - Part 3: Equipment Protection by Increased Safety "e" (IEC 60079-7: 2006, IDT) GB 3836.4-2010 Explosive Atmospheres - Part 4: Equipment Protection by Intrinsic Safety “i” (IEC 60079-11: 2006, MOD) GB/T 3836.5-2017 Explosive Atmospheres - Part 5: Equipment Protection by Pressurized Enclosure “p” (IEC 60079-2: 2009, MOD) GB 3836.6 Electrical Apparatus for Explosive Gas Atmospheres - Part 6: Oil Immersion “o” (GB 3836.6-2004, IEC 60079-6: 1995, IDT) GB 3836.7 Electrical Apparatus for Explosive Gas Atmospheres - Part 7: Powder Filling “q” (GB 3836.7-2004, IEC 60079-5: 1997, IDT) GB 3836.8-2014 Explosive Atmospheres - Part 8: Equipment Protection by Type of Protection "n" (IEC 60079-15: 2010, MOD) GB 3836.9-2014 Explosive Atmospheres - Part 9: Equipment Protection by Type of Protection “m” (IEC 60079-18: 2007, IDT) GB 3836.13-2013 Explosive Atmospheres - Part 13: Equipment Repair, Overhaul and Reclamation (IEC 60079-19: 2010, MOD) GB 3836.14-2014 Explosive Atmospheres - Part 14: Classification of Areas - Explosive Gas Atmosphere (IEC 60079-10-1: 2010, IDT) GB/T 3836.16-2017 Explosive Atmospheres - Part 16: Electrical Installation Inspection and Maintenance (IEC 60079-17: 2007, IDT) GB 3836.17-2007 Electrical Apparatus for Explosive Gas Atmospheres - Part 17: Construction and Use of Rooms or Buildings Protected by Pressurization GB/T 3836.18-2017 Explosive Atmospheres - Part 18: Intrinsically Safe Electrical Systems (IEC 60079-25: 2010, MOD) GB 3836.19-2010 Explosive Atmospheres - Part 19: Fieldbus Intrinsically Safe Concept (FISCO) (IEC 60079-27: 2003, IDT) GB 3836.20-2010 Explosive Atmospheres - Part 20: Equipment with Equipment Protection Level (EPL) Ga (IEC 60079-26: 2006, IDT) GB/T 3836.22-2017 Explosive Atmospheres - Part 22: Protection of Equipment and Transmission System using Optical Radiation (IEC 60079-28: 2006, MOD) GB/T 4208 Degrees of Protection Provided by Enclosure (IP Code) (GB/T 4208-2017, IEC 60529: 2013, IDT) GB 4793.1 Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use-Part 1: General Requirements (GB 4793.1-2007, IEC 61010-1:2001, IDT) GB/T 4942.1 Degrees of Protection Provided by the Integral Design of Rotating Electrical Machined (IP Code) - Classification (GB/T 4942.1-2006, IEC 60034-5: 2000, IDT) GB 4943.1 Information Technology Equipment - Safety - Part 1: General Requirements (GB 4943.1-2011, IEC 60950-1: 2005, MOD) GB 12476.1-2013 Electrical Apparatus for Use in the Presence of Combustible Dust - Part 1: General Requirements (IEC 61241-0: 2004, MOD) GB/T 12476.3-2017 Electrical Apparatus for Use in the Presence of Combustible Dust - Part 3: Classification of Areas Where Combustible Dusts are or May be Present (IEC 60079-10-2: 2009, IDT) GB 12476.4-2010 Electrical Apparatus for Use in the Presence of Combustible Dust - Part 4: Protection by Intrinsic Safety “iD” (IEC 61241-11: 2005, IDT) GB 12476.5-2013 Electrical Apparatus for Use in the Presence of Combustible Dust - Part 5: Protection by Enclosures “tD” (IEC 61241-1: 2004, IDT) GB 12476.6-2010 Electrical Apparatus for Use in the Presence of Combustible Dust - Part 6: Protection by Enclosures “tD” (IEC 61241-18: 2004, IDT) GB 12476.7-2010 Electrical Apparatus for Use in the Presence of Combustible Dust - Part 7: Type of Protection “pD” (IEC 61241-4: 2001, IDT) GB 12476.8-2010 Electrical Apparatus for Use in the Presence of Combustible Dust - Part 8: Test Methods - Methods for Determining the Minimum Ignition Temperatures of Dust (IEC 61241-2-1: 1994, IDT) GB/T 16895.21-2011 Low-voltage Electrical Installations - Part 4-41: Protection for Safety - Protection Against Electric Shock (IEC 60364-4-41: 2005, IDT) GB/T 16927.1 High-voltage Test Techniques - Part 1: General Definitions and Test Requirements (GB/T 16927.1-2011, IEC 60060-1:2006, MOD) GB/T 18380.12 Test on Electric and Optical Fibre Cables under Fire Conditions - Part 12 Test for Vertical Flame Propagation for a Single Insulated Wire or Cable - Procedure for 1kW Pre-mixed Flame (GB/T 18380.12-2008, IEC 60332-1-2: 2004, IDT) GB/T 19212.7 Safety of Transformers, Reactors, Power Supply Units and Similar Products for Supply Voltages up to 1 100 V - Part 7: Particular Requirements and Test for Safety Isolating Transformers and Power Supply Units Incorporating Saftey Isolating Transformers (GB/T 19212.7-2012, IEC 61558-2-6: 2009,IDT) GB/T 21714.3-2015 Protection Against Lightning - Part 3: Physical Damage to Structures and Life Hazard (IEC 62305-3: 2010, IDT) GB/T 29812 Industrial-process Control - Safety of Analyser Houses. IEC 60079-16 Electrical Apparatus for Explosive Gas Atmospheres - Part 16:Artificial Ventilation for the Protection of Analyzer(s) Houses 3 Terms and Definitions For the purposes of this document, the terms and definitions given in GB 3836.1-2010 and the following apply. Note: Additional definitions applicable to explosive atmospheres can be found in GB/T 2900.35-2008. 3.1 general 3.1.1 competent body individual or organization which can demonstrate appropriate technical knowledge and relevant skills to make the necessary assessments of the safety aspect under consideration 3.1.2 verification dossier set of documents showing the compliance of electrical equipment and installations 3.2 hazardous areas 3.2.1 hazardous areas area in which an explosive atmosphere is present, or may be expected to be present, in quantities such as to require special precautions for the construction, installation and use of equipment Note: For the purposes of this art, an area is a three-dimensional region or space. 3.2.2 non-hazardous area area in which an explosive atmosphere is not expected to be present in quantities such as to require special precautions for the construction, installation and use of equipment 3.2.3 group (of an electrical equipment for explosive atmospheres) classification of electrical equipment related to the explosive atmosphere for which it is to be used Note: Electrical equipment for use in explosive atmospheres is divided into three groups: —— group I: electrical equipment for mines susceptible to firedamp; —— group II (which can be divided into subgroups): electrical equipment for places with an explosive gas atmosphere, other than mines susceptible to firedamp (methane) (see 5.5); —— group III (which can be divided into subgroups): electrical equipment for places with an explosive dust atmosphere (see 5.5). 3.2.4 maximum permissible surface temperature highest temperature that a surface of electrical apparatus is allowed to reach in practical service to avoid ignition Note: The maximum permissible surface temperature will depend upon the type of dust, whether as a cloud or layer, if a layer, its thickness and the application of a safety factor. For details see 5.6.3. 3.2.5 Zones hazardous areas classified into zones based upon the frequency of the occurrence and duration of an explosive atmosphere 3.2.6 zone 0 place in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas, vapour or mist is present continuously or for long periods or frequently 3.2.7 zone 1 place in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally 3.2.8 zone 2 place in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas, vapour or mist is not likely to occur in normal operation but, if it does occur, will persist for a short period only 3.2.9 zone 20 area in which an explosive atmosphere in the form of a cloud of combustible dust in air is present continuously, or for long periods or frequently 3.2.10 zone 21 area in which an explosive atmosphere in the form of a cloud of combustible dust in air is likely to occur, occasionally, in normal operation 3.2.11 zone 22 area in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation but, if it does occur, will persist for a short period only 3.3 flameproof enclosure 3.3.1 flameproof enclosure “d” type of protection in which the parts capable of igniting an explosive gas atmosphere are provided with an enclosure which can withstand the pressure developed during an internal explosion of an explosive mixture and which prevents the transmission of the explosion to the explosive gas atmosphere surrounding the enclosure 3.3.2 pressure-piling increased pressure resulting from an ignition, in a compartment or subdivision of an enclosure due to a gas mixture being pre-compressed, e.g. due to a primary ignition in another compartment or subdivision Note: This may lead to a higher maximum pressure than would otherwise be expected. 3.4 increased safety 3.4.1 increased safety “e” type of protection applied to electrical equipment in which additional measures are applied so as to give increased security against the possibility of excessive temperatures and of the occurrence of arcs and sparks in normal service or under specified abnormal conditions 3.4.2 initial starting current IA highest r.m.s. value of current absorbed by an a.c. motor at rest or by an a.c. magnet with its armature clamped in the position of maximum air gap, when supplied at the rated voltage and rated frequency 3.4.3 starting current ratio IA/IN ratio between initial starting current IA and rated current IN 3.4.4 time tE time taken for an a.c. rotor or stator winding, when carrying the initial starting current I A , to be heated up to the limiting temperature from the temperature reached in rated service at the maximum ambient temperature 3.5 intrinsic safety - general 3.5.1 intrinsic safety “i” type of protection based upon the restriction of electrical energy within equipment and of interconnecting wiring exposed to an explosive atmosphere to a level below that which can cause ignition by either sparking or heating effects Note: Because of the method by which intrinsic safety is achieved, it is necessary to ensure that not only the electrical equipment exposed to the explosive atmosphere but also other electrical equipment with which it is interconnected is suitably constructed. 3.5.2 intrinsically safe apparatus electrical apparatus in which all the circuits are intrinsically safe Note: Intrinsically safe apparatus should conform to GB 3836.4-2010, level of protection “ia”, “ib” or “ic”. 3.5.3 galvanic isolation arrangement within an item of intrinsically safe apparatus or associated apparatus which permits the transfer of signals or power between two circuits without any direct electrical connection between the two Note: Galvanic isolation frequently utilizes either magnetic (transformer or relay) or opto-coupled elements. 3.5.4 simple apparatus electrical component or combination of components of simple construction with well-defined electrical parameters which is compatible with the intrinsic safety or energy-limited safety of the circuit in which it is used Note: The following apparatus is considered to be simple apparatus: a) passive components, e.g. switches, junction boxes, resistors and simple semi-conductor devices; b) sources of stored energy with well-defined parameters, e.g. capacitors or inductors, whose values are considered when determining the overall safety of the system; c) sources of generated energy, e.g. thermocouples and photocells, which do not generate more than 1.5 V, 100 mA and 25 mW. 3.5.5 intrinsically safe circuit circuit in which all the equipment is either intrinsically safe apparatus or simple apparatus Note: The circuit may also contain associated apparatus. 3.5.6 intrinsically safe electrical system assembly of interconnected items of electrical equipment, described in a descriptive system document, in which the circuits or parts of circuits intended to be used in an explosive atmosphere are intrinsically safe 3.5.7 intrinsically safe sub-circuit part of an intrinsically safe circuit which is galvanically isolated from another part or other parts of the same intrinsically safe circuit 3.6 intrinsic safety parameters 3.6.1 maximum external inductance to resistance ratio, Lo/Ro ratio of inductance (Lo) to resistance (Ro) of any external circuit connected to the connection facilities of the electrical equipment without invalidating intrinsic safety 3.7. pressurization 3.7.1 pressurization “p” technique of guarding against the ingress of the external atmosphere into an enclosure by maintaining a protective gas therein at a pressure above that of the external atmosphere. Note: Pressurization should conform to GB/T 3836.5-2017 “px”, “py” or “pz”. 3.7.2 continuous dilution (flow) continuous supply of a protective gas, after purging, at such a rate that the concentration of a flammable substance inside the pressurized enclosure is maintained at a value outside the explosive limits at any potential ignition source (that is, outside the dilution area) Note: The dilution area is an area in the vicinity of an internal source of release where the concentration of a flammable substance is not diluted to a safe concentration.

Foreword I Introduction V 1 Scope 2 Normative References 3 Terms and Definitions 4 General 5 Selection of Equipment (Excluding Cables and Conduits) 6 Protection from Dangerous (Incendive) Sparking 7 Electrical Protection 8 Emergency Switch-off and Electrical Isolation 9 Wiring Systems 10 Additional Requirements for Type of Protection "d" - Flameproof Enclosures 11 Additional Requirements for Type of Protection "e" - Increased Safety 12 Additional Requirements for Type of Protection "i" - Intrinsic Safety 13 Additional Requirements for Type of Protection 'p" - Pressurized Enclosures 14 Additional Requirements for Type of Protection 'n' 15 Additional Requirements for Type of Protection 'o’ - Oil Immersion 16 Additional Requirements for Type of Protection 'q' - Powder Filling 17 Additional Requirements for Type of Protection 'm’ - Encapsulation 18 Additional Requirements for Type of Protection 'tD' – Protection by Enclosure Annex A (Normative) Verification of Intrinsically Safe Circuits with More than One Associated Apparatus with Linear Current/Voltage Characteristics Annex B (Informative) Methods of Determining the Maximum System Voltages and Currents in Intrinsically Safe Circuits with More than One Associated Apparatus with Linear Current/Voltage Characteristics (as Required by Annex A) Annex C (Informative) Determination of Cable Parameters Annex D (Informative) Safe Work Procedure Guidelines for Explosive Gas Atmospheres Annex E (Normative) Potential Stator Winding Discharge Risk Assessment - Ignition Risk Factors Annex F (Normative) Knowledge, Skills and Competencies of Responsible Persons, Operatives and Designers Annex G (Informative) Examples of Dust Layers of Excessive Thickness Annex H (Normative) Frictional Sparking Risks with Light Metals and Their Alloys Annex I (Informative) Introduction of an Alternative Risk Assessment Method Encompassing “Equipment Protection Levels” for Ex Equipment Bibliography