GB/T 3836.5-2021 English PDFUS$939.00 · In stock
Delivery: <= 8 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 3836.5-2021: Explosive atmospheres - Part 5: Equipment protection by pressurized enclosure 'p' Status: Valid GB/T 3836.5: Historical versions
Basic dataStandard ID: GB/T 3836.5-2021 (GB/T3836.5-2021)Description (Translated English): Explosive atmospheres - Part 5: Equipment protection by pressurized enclosure "p" Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: K35 Word Count Estimation: 52,536 Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration GB/T 3836.5-2021: Explosive atmospheres - Part 5: Equipment protection by pressurized enclosure "p"---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. Explosive atmospheres - Part 5.Equipment protection by pressurized enclosure "p" ICS 29.260.20 CCSK35 National Standards of People's Republic of China Replace GB/T 3836.5-2017, GB 12476.7-2010 Explosive environment Part 5.Equipment protected by a positive pressure enclosure "p" (IEC 60079-2.2014,Explosiveatmospheres-Part 2.Equipment Released on 2021-10-11 2022-05-01 implementation State Administration for Market Regulation Issued by the National Standardization Management Committee Table of contentsForeword Ⅲ Introduction Ⅵ 1 Scope 1 2 Normative references 1 3 Terms and definitions 2 4 Protection level 4 5 Structural requirements for positive pressure enclosures 6 6 Temperature limit 8 7 Safety measures and safety devices (except static positive pressure protection) 8 8 Safety measures and safety devices for static positive pressure 12 9 Supply of protective gas 13 10 Positive pressure housing with internal release source 14 11 Release conditions 14 12 Design requirements for built-in systems 14 13 Shielding gas with internal release source and positive pressure technology 15 14 Equipment capable of igniting 17 15 Internal hot surface 17 16 Type inspection and test 17 17 Routine test 20 18 logo 21 19 Operating Instructions 22 Appendix A (normative) Ventilation and dilution test 24 Appendix B (informative) Example of functional program diagram 25 Appendix C (informative) Examples of pressure changes in pipes and enclosures 27 Appendix D (informative) Information provided to users 31 Appendix E (Normative) Classification of Release Types in Enclosures 33 Appendix F (informative) Examples of the use of the principle of dilution zone 34 Appendix G (Normative) Applies to internal batteries and battery packs with "pxb" and "pyb" protection levels 36 Appendix H (Normative) Applies to internal batteries and battery packs with "pzc" protection level 42 Reference 44 Explosive environment Part 5.Equipment protected by a positive pressure enclosure "p"1 ScopeThis document specifies the structure and testing of electrical equipment used in explosive gas atmospheres or explosive dust environments protected by a positive pressure enclosure "p" The special requirements also stipulate the requirements for containing positive pressure enclosures that restrict the release of flammable substances. This document is applicable to electrical equipment protected by a positive pressure enclosure "p" intended to be used in an explosive gas environment or an explosive dust environment. This document does not apply to. ---Positive pressure enclosures where the built-in system may release the following substances. ● Air with oxygen content exceeding the normal value; or ● Oxygen is mixed with inert gas, and the proportion of oxygen exceeds 21%. ---Pressure room or analysis room, see GB/T 3836.17. ---A positive pressure enclosure used in an environment where explosives or fireworks are present. ---Used in the presence of gas/vapor and combustible dust mixed in the environment of the positive pressure shell. ---Use the positive pressure shell in an environment where there are self-igniting substances such as explosives or propellants that contain oxidants. ---Positive pressure shell with flammable dust release source inside. Note. When the user is a manufacturer, under normal circumstances, it is the user's responsibility to ensure that all relevant requirements of this document are applicable to the manufacturing and testing of the equipment. This document is a supplement and modification to the general requirements of GB/T 3836.1.When the requirements of this document conflict with those of GB/T 3836.1 In the event of an emergency, the requirements of this document shall take precedence.2 Normative referencesThe content of the following documents constitutes an indispensable clause of this document through normative references in the text. Among them, dated quotations Only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to This document. GB/T 2900.35 Electrical terminology equipment for explosive atmospheres (GB/T 2900.35-2008, IEC 60050-426.2008, IDT) GB/T 2900.83 Electrical terminology, electrical and magnetic devices (GB/T 2900.83-2008, IEC 60050-151.2001, IDT) GB/T 3836.1 Explosive environment Part 1.General requirements for equipment (GB/T 3836.1-2021, IEC 60079-0. 2017, MOD) GB/T 3836.4 Explosive atmosphere Part 4.Equipment protected by intrinsically safe "i" (GB/T 3836.4-2021, IEC 60079-11.2011, MOD) GB/T 3836.8 Explosive atmosphere Part 8.Equipment protected by "n" type (GB/T 3836.8-2021, IEC 60079-15. 2017, MOD) GB/T 4207 Method for determination of tracking resistance index and comparative tracking index of solid insulating materials (GB/T 4207-2012, IEC 60112.2009, IDT) GB/T 4208 Enclosure protection grade (IP code) (GB/T 4208-2017, IEC 60529.2013, IDT) GB/T 4942.1 Protection level (IP code) classification of the overall structure of rotating electrical machines (GB/T 4942.1-2006, IEC 60034-5. 2000, IDT) GB/T 9364 (all parts) small fuses [IEC 60127 (all parts)]5 Structural requirements for positive pressure enclosures5.1 Housing The positive pressure enclosure shall have a protection level in accordance with Table 2. For the "pxb" protection level of internal components that do not exceed the marked temperature group, as well as the "pyb" and "pzc" protection levels, non-metallic exterior The heat and cold resistance test (GB/T 3836.1) of the shell and the non-metallic parts of the shell does not have to be used for the positive pressure shell. This is because the degradation of the casing leads to an increase in the leakage rate, which can cause alarms and cut off the power of the circuit with the ability to ignite. Therefore, non-metal The pretreatment test of the enclosure and the non-metallic parts of the enclosure is not considered necessary. 5.2 Material The materials used for the housing, pipes and connectors shall not be adversely affected by the specified protective gas. 5.3 Doors and covers 5.3.1 Type I positive pressure enclosure The door and cover should. ---Use special fasteners that meet the requirements of GB/T 3836.1; or --- Interlocking is used so that when the door and cover are opened, the electrical equipment that is not protected by the equipment protection level (EPL) listed in 7.15 can be supplied The electric power can be cut off automatically, and the power cannot be re-energized before the door and cover are closed. At the same time, it should also meet the requirements of 7.7. 5.3.2 Class I positive pressure enclosure with static positive pressure protection Doors and covers should use special fasteners that meet the requirements of GB/T 3836.1. 5.3.3 Type Ⅱ positive pressure enclosure The requirements for special fasteners specified in GB/T 3836.1 do not apply. For the "pxb" protection level, doors and lids that can be opened without tools or keys should be interlocked so that when they are in an open state In the state, the power supply to the electrical equipment not listed in 7.15 protection can be automatically cut off, and the power can not be re-energized before the door and cover are closed. For the "pyb" and "pzc" protection levels, there is no requirement on whether to use tools or keys. It should be considered that when the fasteners are loosened, the high internal pressure may cause the door or cover to open suddenly. The following methods should be used to prevent operators And maintenance personnel were injured. a) Use multiple fasteners to safely vent the enclosure before loosening all fasteners; or b) Double-position fasteners are used to safely discharge pressure when the shell is opened; or c) Limit the maximum internal pressure to not more than 2.5kPa. 5.3.4 Positive pressure enclosures of category Ⅱ and Ⅲ with static positive pressure protection Doors and covers should only be opened with tools. 5.3.5 Type Ⅱ and Ⅲ. pxb type For positive pressure enclosures containing hot parts that require cooling time, they should not be easily opened without tools or keys. 5.3.6 Warnings for Class Ⅱ and Ⅲ Doors and Covers In order to prevent the explosive gas or dust from being ignited due to the opening of the enclosure, the door and cover should be marked. "Warning. It is strictly forbidden to open in an explosive environment" 5.4 Mechanical strength During normal operation, the positive pressure housing and its pipes and their connecting parts shall withstand the manufacturer's requirements when all vents are closed. The maximum positive pressure is 1.5 times the pressure, and the minimum pressure is.200Pa. If pressure that may cause deformation of the shell, pipeline or connecting parts occurs during work, a safety device should be installed to reduce the maximum internal positive pressure. The value is limited to a level below which may adversely affect the type of protection. If the manufacturer does not provide safety devices, the equipment explosion-proof certificate The number shall include the “X” suffix in accordance with the marking requirements in GB/T 3836.1, and the special use conditions listed in the explosion-proof certificate shall be stated in detail Specify the necessary information required by the user to ensure compliance with the requirements of this document. 5.5 Class Ⅰ and Ⅱ pores, partitions, partitions and internal components 5.5.1 The arrangement of air holes and partitions shall ensure effective ventilation. The unvented area can be eliminated by appropriately setting the inlet and outlet holes for the protective gas supply and the effect of the partition plate. For gas or vapor heavier than air, the inlet hole of the protective gas should be close to the top of the positive pressure shell, and the exhaust hole should be close to the top of the shell. bottom. For gases or vapors lighter than air, the inlet holes of the protective gas should be close to the bottom of the shell, and the exhaust holes should be close to the top of the shell. Air intake holes and exhaust holes are provided on opposite sides of the housing to promote front and rear ventilation. The internal partition (such as a circuit board) should be arranged so that the flow of the protective gas is not obstructed. The use of branch pipes or baffles can also improve obstacles The air flow around. The number of pores should be selected according to the structure of the equipment, especially considering that the electrical equipment may be divided into some small cavities for ventilation. 5.5.2 The inner compartment should be communicated with the main enclosure or be ventilated separately. For every 1000cm3, a vent hole with an area of not less than 1cm2 is provided, and a vent hole with a minimum diameter of 6.3mm is usually sufficient Proper ventilation. 5.5.3 Cathode ray tubes (CRTs) and other airtight devices do not require ventilation. 5.5.4 For components with a net internal volume less than 20cm3, as long as the total volume of all such components does not exceed 1% of the net internal volume of the positive pressure enclosure, It is regarded as an internal cavity that does not require ventilation. Note. 1% is based on 25% of the lower combustion limit (LFL) of hydrogen, see A.2. Electrical components that are considered to be sealed, such as transistors, microcircuits, capacitors, etc., are not included in the calculation of the total volume of the components. 5.6 Air holes of the static positive pressure protection enclosure The static positive pressure protection enclosure should have one or more air holes. After inflation and positive pressure protection, all air holes should be closed. 5.7 Insulation material For Class I electrical equipment, it can withstand the rated current greater than 16A (in switchgear such as circuit breakers, contactors, and isolators) The insulating material that is sufficient to generate electric arc stress in the air shall meet at least one of the following requirements. ---Comparative tracking index is equal to or greater than CTI400M in the GB/T 4207 standard. ---Set up an appropriate device, which can detect the dangerous situation that the insulating material inside the shell may decompose, and automatically on the power supply side Cut off the power supply to the enclosure. The installation and function of such devices shall be verified. ---The creepage distance of the live bare conductor conforms to the creepage shown by the equivalent voltage of the third-grade pollution-related materials in GB/T 16935.1 distance. 5.8 Seal All cables and conduits connected to the enclosure should be sealed to maintain the protection level of the enclosure. If it is not sealed, it is regarded as part of the housing. 5.9 Spark and particle baffle The pipes for the positive pressure shell and the protective gas should be equipped with spark and particle baffles to prevent hot particles from blowing into the dangerous place. Unless the working current of the on-off contacts is less than 10A, and the working voltage does not exceed 275V (AC) or 60V (DC), and the contacts should If there is an arc extinguisher, it is considered that no hot particles are generated, otherwise it should be considered that hot particles may usually be generated. If hot particles are not normally produced, it is not necessary to discharge into the normally closed decompression port where the equipment protection level is Gb or Mb. To spark and particle baffle. If hot particles are usually not produced, sparks and particles are not required at the exhaust port when the equipment is discharged into a place where the protection level of the equipment is Gc. Bezel. If the manufacturer does not provide spark and particle baffles, the equipment explosion-proof certificate number shall be included in accordance with the marking requirements in GB/T 3836.1 "X suffix, and the special conditions of use listed in the explosion-proof certificate shall specify the necessary requirements for the user to ensure compliance with the requirements of this document. information. 5.10 Batteries and battery packs "Pxb" and "pyb" protection level internal batteries and battery packs should meet the requirements of Appendix G, "pzc" protection level internal batteries and batteries The group shall meet the requirements of Appendix H.6 Temperature limit6.1 General Equipment should be grouped according to the temperature group requirements in GB/T 3836.1, and should be determined in accordance with 6.2 and 6.3. 6.2 For "pxb" or "pyb" protection level The temperature group should depend on the higher of the following temperatures. a) The maximum outer surface temperature of the enclosure; or b) Maximum surface temperature of internal components. Exception. Internal components can exceed the marked temperature group if. 1) Meet the relevant "small components" requirements in GB/T 3836.1; or 2) The positive pressure shell is "pxb" protection level, and meets the opening time requirements of GB/T 3836.1.If the positive pressure protection is interrupted, Appropriate measures should be taken to prevent the possibility of the Any flammable mixture that appears in contact with any surface of the heating element. The above requirements can be achieved through the design and structure of the positive pressure housing and pipe joints or other methods, for example, the auxiliary ventilation system Enter the working state or place the hot surface in the positive pressure shell in an airtight or encapsulated shell. In the "pyb" protection class enclosure, there should be no thermal element capable of igniting under normal operating conditions. 6.3 For "pzc" protection level The temperature group should be based on the highest outer surface temperature of the enclosure. When determining the temperature group, the explosion-proof equipment that is still live when the positive pressure system is disconnected should be considered. 7 Safety measures and safety devices (except static positive pressure protection) 7.1 Applicability of safety devices in hazardous locations All safety devices used to prevent ignition of electrical equipment for positive pressure protection shall not cause ignition by themselves (see 7.15) or be installed in Outside the hazardous area. 7.2 Integrity of safety devices The safety devices required by this document (see Table 3) constitute safety components related to the control system. The safety and integrity of the control system should confirm. Positive pressure system should be tested to verify the correctness of operation. 7.4.3 Positive pressure system with "pxb" protection level The positive pressure system shall include. a measure to control the lowest positive pressure value (such as a regulator) that meets the requirements of 7.11, and a verification of the lowest positive pressure value Measures (such as pressure sensors) and an automatic safety device, as well as an automatic control system that meets the requirements of 7.7 using flow sensors. If a regulator is used, and in the case of a single failure, all the pressure at the air inlet will be applied to the air outlet of the regulator, then use A measure to limit the pressure inside the enclosure to a specified value (such as a pressure relief port). This specified value is obtained by experiment or calculation and needs to be listed in In the instruction manual. If there are multiple regulators or pressure relief ports to choose from, then the specified value of each suitable regulator/pressure relief port should be Sure. The positive pressure system shall be tested to verify the correct operation including the functions of the automatic control system. 7.5 "pxb" program diagram For the "pxb" protection level positive pressure system, the functional program diagram should be provided by the manufacturer, such as truth table, state diagram, flow chart, etc. Determine the role of the control system. The program diagram should be clearly distinguishable and indicate the operating status and subsequent actions of the safety device. On request Functional test to verify whether it is consistent with the program diagram. These tests only need to be carried out under normal environmental conditions, unless otherwise specified by the manufacturer. Note. Appendix B gives an example of the information provided by the manufacturer. 7.6 Safety device ratings The manufacturer shall specify the maximum and minimum operating values and tolerances of the safety device. The safety device should be in the normal working range as specified by the manufacturer Used within. 7.7 Automatic ventilation of positive pressure enclosures of "pxb" protection class Ⅰ and Ⅱ An automatic control system with safety devices should be installed to prevent the electrical equipment in the positive pressure enclosure from being energized before the ventilation is completed. The operating procedures of the control system should be as follows. a) After the start of the procedures specified in this document, the ventilation flow through the positive pressure enclosure and the lowest positive pressure in the enclosure should be monitored; b) When the minimum flow rate of the protective gas is reached and the positive pressure value ......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB/T 3836.5-2021_English be delivered?Answer: Upon your order, we will start to translate GB/T 3836.5-2021_English as soon as possible, and keep you informed of the progress. The lead time is typically 5 ~ 8 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB/T 3836.5-2021_English with my colleagues?Answer: Yes. 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