Equipment in this category is intended for use in Zone 0 areas (gases) or Zone 20 (dusts), and must ensure a very high level of protection (i.e. Informational Note No. Beside the Lower Explosion Limit, each substance also has an Upper Explosion Limit (UEL). A Class I, Division 1 or Division 2 location may be reclassified as a Class I, Zone 0, Zone 1, or Zone 2 location only if all of the space that is classified because of a single flammable gas or vapor source is reclassified. This level of risk is represented by classifying the hazardous area as Zone 0, Zone 1 or Zone 2 (for gas, vapour and mist atmospheres) or Zone 21 or Zone 22 for dust atmospheres. Powder Filling "q" -- This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. Atmosphere containing carbonaceous dusts, Atmosphere containing combustible dust not included in Group E & F - such as. *unless risk assessment states a higher or lower category is required. Equipment shall be marked to show the class, group, and operating temperature or temperature range, based on operation in a 40-degree C ambient, for which it is approved. 1: As a guide in determining when flammable gases or vapors are present continuously or for long periods of time, refer to ANSI/API RP 505-2018, Informational Note No. Raytec do not currently offer any lighting solutions for Zone 0. These generally give rise to areas classied as Zones 0, 1, and 2 respectively. may exist under normal or abnormal conditions because of the presence of flammable gases or vapors, combustible dusts or ignitable fibers or flyings. The prevention of explosions in working environments is in most countries regulated in national laws and directives. Sources July 2022 February 2022 Type of protection "n" is further subdivided into nA, nC, and nR. The a subdivisions have the most stringent safety requirements, taking into account more than one independent component faults simultaneously. Substances characterization Consequences . Pressurised Container This is because Zone 0 usually classifies areas for gas storage or containment, and any lighting required would be used on a small and portable basis for visual inspection, e.g. Carbon monoxide, ether, hydrogen sulfide, . Type of protection "n" -- This protection technique is permitted for equipment in the Class I, Zone 2 locations for which it is approved. However, the following provisions modify this marking requirement for specific equipment: Fixed lighting fixtures marked for use in Class I, Division 2 or Class II, Division 2 locations only need not be marked to indicate the group; Fixed general-purpose equipment in Class I locations, other than lighting fixtures, that is acceptable for use in Class I, Division 2 locations need not be marked with the class, group, division, or operating temperature; Fixed dust-tight equipment, other than lighting fixtures, that is acceptable for use in Class II, Division 2 and Class III locations need not be marked with the class, group, division, or operating temperature; and. For example, a Class 1, Div 1 area where Group A may be present would be defined as an area where flammable gases or vapors may be present under normal operating conditions. All equipment in Division 1 areas must have an approval label, but certain materials, such as rigid metallic conduit, does not have a specific label indicating the Cl./Div.1 suitability and their listing as approved method of installation in the NEC serves as the permission. But first, we must consider what is likely to cause an explosion in the first place. February 2023 The definition of Zone 2 is a hazardous area classified as an atmosphere where a mixture of air and 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. Equipment can be designed or modified for safe operation in hazardous locations. Hazardous areas are defined as: " Zones " under worldwide IEC standards (and their local versions, such as ATEX in Europe) " Divisions " under North American NEC standards. The IEC standard EN 60079-33 is made public and is expected to become effective soon, so that the normal Ex certification will also be possible for Ex-s, Zone depending upon manufacturer's certification, explosive atmosphere between 10 and 1000 hrs/yr, explosive atmosphere between 1 and 10 hrs/yr, explosive surface between 10 and 1000 hrs/yr, explosive surface between 1 and 10 hrs/yr, Certified and labeled for use in indoor locations rated NEC Class I, Groups A, B, C, and D, Certified and labeled for use in locations rated NEC Class I, Groups A, B, C, and D; both indoors and outdoors, Certified and labeled for use in locations rated NEC Class II, Groups E, F, or G, Explosion protected, Group 2, Category 1, Gas, Type ia, Group 2C gases, Temperature class 4, Type n, non-sparking, Group 2 gases, Temperature class 3, special conditions apply. Use this hazardous area guide to NFPA 70 location classes, divisions & groups to understand potentially dangerous situations at a glance. Standards and regulations exist to identify such locations, classify the hazards, and design equipment for safe use in such locations. There are several ways of how to perform hazardous area classification, all described in several standards or codes of practise. Equipment is non-incendive or non-sparking. In many industrial, commercial, and scientific settings, the presence of such an atmosphere is a common, or at least commonly possible, occurrence. As a guide for Zone 0, this can be defined as over 1,000 hours/year or >10% of the time. If equipment is marked, for example, Ex e II T4 then it is suitable for all subgroups IIA, IIB and IIC. Some manufacturers claim "suitability" or "built-to" hazardous areas in their technical literature, but in effect lack the testing agency's certification and thus unacceptable for the AHJ (Authority Having Jurisdiction) to permit operation of the electrical installation/system. with hazardous areas EC-Type Examination Certificate BAS 01 ATEX 7251 , for additional certificates see www.pepperl-fuchs.com Group, category, type of protection II (1) G D [EEx ia] IIB (-20 C Ta 60 C) [circuit(s) in zone 0/1/2] Output EEx ia IIB Voltage U0 25.9 V Current I0 184 mA Power P0 1.2 W Type of protection [EEx ia] Entire Vapour space of storage tank. Zone 0Ignitable concentrations of flammable gases or vapors which are present continuously or for long periods of time. Ex Zone. Iso Container Determining the Class, Division and Group or Zone and Group is critical to correctly applying the requirements for a given hazardous location. LIFTING TEST Zone type (0/1/2/ 20/21/ 22) Zone extent. The Zone system has three levels of hazard for gas or dust where the Division system has two. Comparison of Zones and Divisions. Flameproof "d" - This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. Category 1 equipment may be used in zone 0, zone 1 or zone 2 areas. 4: For further information on protection against static electricity and lightning hazards in hazardous (classified). EN 16985 concerning spray cabins and powder coating cabins, EN 12779 related to extraction systems for hot sawdust and chips, EN 60079-10 series, 2020 version for gas and dust explosion hazard, NPR 7910 series for gas and dust explosion hazard based on EN 60079-10-1, 2015 version, EN 13617 for fuel dispensers at filling stations. If equipment has been approved for use in a Division 1 hazardous location, it can be used in a Division 2 hazardous location, providing it is in the same class and group. [3], Different explosive atmospheres have chemical properties that affect the likelihood and severity of an explosion. 5: For further information on ventilation, see NFPA 30-2018, Informational Note No. . Fundamentally, for an explosion to take place, flammable or explosive gases, vapours, mists or dusts will be present. |MWD/LWD Cabin November 2022 . Zone 0 Zone 1 Zone 2 Fluid Occurrence of explosive atmosphere Gas mixtures Dust mixtures Not likely to occur or only for short period Zone 2 Zone 22 . Horizontal. ESS Container Also known as non-hazardous or ordinary locations, these locations are determined to be neither Class I, Division 1 or Division 2; Zone 0, Zone 1 or Zone 2; or any combination thereof. These areas only become hazardous in case of an accident or some unusual operating condition. Hazardous Area Classification (HAC) is as follows: Definitions of hazardous area are different as per IEC and NEC. 1.1.1 This recommended practice applies to those locations where flammable gases or vapors, flammable liquids, or combustible liquids are processed or handled; and where their release into the atmosphere could result in their ignition by electrical systems or equipment. Laboratory Container Motors, lighting, junction boxes, electronic equipment, This method, being by definition special, has no specific rules. This blog post will focus on the different hazardous location classifications and well follow up with another that discusses how equipment can be constructed and certified for use in these environments. What is an Explosion Protection Document? Beside sufficient fuel, also sufficient oxygen is needed for combustion of the mixture. Zone defines the general nature - if it is a gas or dust - and the probability of hazardous material being present in an ignitable concentration in the surrounding atmosphere. Australia and New Zealand use the same IEC-60079 standards (adopted as AS/NZS60079), however the CE mark is not required. Exception No. Several protection strategies exist. [1] NEC article 500 describes the NEC Division classification system, while articles 505 and 506 describe the NEC Zone classification system. The minimum concentration of oxygen, necessary for the combustion to take place, is called the Limiting Oxygen Concentration. . Equipment of the nonheat-producing type, such as junction boxes, conduit, and fittings, and equipment of the heat-producing type having a maximum temperature not more than 100 C (212 F) need not have a marked operating temperature or temperature range; Electric equipment suitable for ambient temperatures exceeding 40 C (104 F) shall be marked with both the maximum ambient temperature and the operating temperature or temperature range at that ambient temperature; and. Get more great content like this sent to your inbox. In some cases, it must be certified as meeting that standard. February 2019 SEWAGE TREATMENT September 2021 Area which are not devided into Atex zones, are called non-hazardous area's. Class / Division System In Northerm America, instead of the zone classification system, the Class/Division system is used. July 2019 March 2022 3: For further information on the classification of, Informational Note No. | For Dust this would be Zone 22. August 2018 Conversely if the same material is heated and handled above its flash-point, the area must be classified for proper electrical system design, as it will then form an ignitable mixture.[5]. Class I, Zone 0 = Area Classification, AEx = Symbol for equipment built to American specifications, ia = Type of protection designations, IIC = Gas classification group (as required), T6 = Temperature Classification, [46 FR 4056, Jan. 16, 1981; 46 FR 40185, Aug. 7, 1981; 72 FR 7210, Feb. 14, 2007], Occupational Safety & Health Administration. Electrical equipment installation in atmosphere with flammable gases or vapors, flammable liquids, combustible dusts, ignitable fibers or flyings represents a risk for fire and explosion. Division defines the likelihood of the hazardous material being present in an explosive or ignitable concentration.Class I flammable gases and vapors are grouped into one of four groups(Groups A, B, C or D)based on their physical properties and the ease in which they can be ignited. This is exactly defined as the limiting concentration of oxygen below which combustion is not possible, independent of the concentration of fuel. - Zone 0: An area where an explosive gas-air mixture is continuously present or present for long time (continuous hazard, whose estimated duration is higher than 1000 hours/year) - Zone 1: An area where an explosive gas-air mixture is likely to occur during normal . Zone 0 (hazardous area) An area in which an explosive gas-air mixture is continuously present or present for long periods. These are typically process areas where gases are more likely to be present. A: When comparing Divisions and Zones, Division 2 is equivalent to Zone 2, but Division 1 is equivalent to either Zone 0 or 1. 7: For further information on application of electrical, Informational Note No. Marking "EEx d" in Accordance with EN 50 0 14 and 50 018 . Lets take a look at what defines each zone. Zone 0, 1, and 2 locations shall include those specified in 505.5 (B) (1), (B) (2), and (B) (3). Equipment marked as suitable for IIB is also suitable for IIA but NOT for IIC. Hazardous locations can also be described as those locations where electrical equipment All emergency versions, whether Zone 1 or Zone 2 can also be easily visually identified by their red end cap, encapsulating the emergency battery back-up. Class I Zone 2 Hazardous Areas. However, at low ambient temperatures, flammable concentrations of vapors may not exist in a location classified Class I, Zone 0, 1, or 2 at normal ambient temperature. Atmospheres containing combustible flyings. Many people have heard terms like Class I, Division 2, Group E, or ATEX zone 21 but many of our customers only know what certification they require with little understanding of what they mean, so we thought it would be appropriate to write a blog post to help customers understand the broader implications of these terms. Zone 2 is a place in which an explosive atmosphere is not likely to occur in normal operation but, if it does occur, will persist for a short period only. Safety is ensured in the event of frequently occurring disturbances or equipment faults which normally have to be taken into account. In instances of areas within the same facility classified separately, Class I, Zone 2 locations may abut, but not overlap, Class I, Division 2 locations. Refrigerated Container You will find these zones at the manifold of a tank truck or the interior of a silo. The flash point determines if an area needs to be classified. Group define the type of hazardous material and (partly) the location of the surrounding atmosphere. Hazardous Area Classification is a study, in which is assessed, at witch locations of a plant, factory or company, high concentrations of flammable gases are present or can be released, in order to create an explosion hazard. Where pyrophoric materials are the only materials used or handled, these locations need not be classified. Protecting against fire and explosion is of interest for both personnel safety as well as reliability reasons. A more quantitative method is described in IEC 60079-10-1 but also more sophisticated numeric mathematical models can be used like Computational Fluid Dynamics. lk) are places where fire or explosion hazards may exist. Equipment approved for use in Class I hazardous locations cannot be used in Class II hazardous locations. A: Yes. Explosion-proofing designs equipment to contain ignition hazards, prevent entry of hazardous substances, and, contain any fire or explosion that could occur. The lower explosion limit of a substance is the lowest concentration (in volume percentages for gases and liquids) of a gas or a vapor in air of producing a flash of fire in the presence of an ignition source. A room with a propane gas installation will typically be classified with the. NFPA 70 NEC establishes area classifications based on Classes, Divisions and Groups that when combined delineate the hazardous conditions of a specific area. Zone 0 - Explosive atmospheres present continuously long periods or frequently. SPARTANs Zone 1 part code begins SPX, Zone 2 SPZ and industrial products having a SPI prefix. Not only are hazardous areas classified by Class (nature of the hazardous material,) and Division . Zone 0 describes an area in which a combustible gas will be present continuously while zone 20 describes an area in which combustible dust will be present continuously (the '2' in 'zone 20' indicates dust as opposed to gas). So a zone 0 is the most hazardous zone and a zone 2 is a less hazardous zone. Zone 0: flammable atmosphere highly likely to be present - may be present for long periods or even continuously . Equipment marked as suitable for Group IIC is also suitable for IIB and IIA. Then, the level of risk of an explosion is based on the frequency and duration of the occurrence of an explosive atmosphere. As world trade becomes more globalized, international standards are slowly converging, so that a wider range of acceptable techniques can be approved by national regulatory agencies. Both external and internal temperatures are taken into consideration. How to perform Hazardous Area Classification? Area Classification. This article is not a substitute for review of current applicable government regulations, industry standards, or other standards specific to your business and/or activities and should not be construed as legal advice or opinion. Under the "Zone" system, hazards are defined for gas as Zone 0, 1 or 2, with 0 as the highest hazard, and for dust as Zone 20, 21 or 22, with 20 as the . . Hazardous areas are classified into zones based on an assessment of the frequency of the occurrence and duration of an explosive gas atmosphere, as shown in the illustration below. National Electrical Code, NFPA 70, Chapter 5, Article 500, 29 CFR 1910 Subpart S, Electrical 1910.307, NFPA 497, "Classification of Gases, Vapors, and Dusts for Electrical Equipment in Hazardous Classified Locations", NFPA Handbook, "Electrical Installations in Hazardous Locations, " by P. J. Schram and M. W. Earley, NFPA 70E, Chapter 5, "Hazardous (Classified) Locations", ANSI/UL 913, "Intrinsically Safe Apparatus", NFPA 496, "Purged and Pressurized Enclosure for Electrical Equipment in Hazardous Locations. That is why the use of mobile phones on petrol forecourts are banned. A light switch may cause a small, harmless spark when switched on or off. Youre phone isnt rated for use in hazardous areas. No other aspect of safety receives more attention in the form of codes and standards. * Zone 1 a location in which explosive gas atmospheres are likely to occur during normal operation, or which is adjacent to a Zone 0 location. Although every application is different, for the ease of monitoring and specification each hazardous area is classified as a particular level or zone. Google use cookies for serving our ads and handling visitor statistics. Table 1. At least two British mine explosions were attributed to an electric bell signal system. 1: Normal operation is considered the situation when plant, Informational Note No. Atmosphere containing flammable gas, flammable liquid produced vapor, or combustible liquid produced vapor mixed with air that may burn or explode, having either a MESG value greater than 0.75 mm or a MIC ratio greater than 0.80 - such as gasoline, acetone, ammonia, benzene, butane, ethanol, hexane, methanol, methane, vinyl chloride, natural gas, naphtha, propane or gases of equivalent hazard. Q: Can equipment approved for a Class I hazardous location be used in a Class II hazardous location? What are 'Dark Factories,' and Do They Really Exist? June 2020 The Occupational Safety and Health Administration (OSHA) has adopted these hazardous classifications and all except Groups are defined in 29 Code of Federal Register (CFR) 1910.399. . All threaded conduit shall be threaded with an NPT (National (American) Standard Pipe Taper) standard conduit cutting die that provides -in. This temperature is used for classification for industry and technology applications.[6]. The codes and standards used in this process provide guidance for selecting,. Zone 0, 1, and 2 locations are those in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitible mixtures. The definition of the hazardous area zones represent the likelihood of hazardous gas, dust or other hazards being present in a working area. To minimize the risk of these fires or explosions, electrical/electronic equipment must be designed, tested and labeled as being acceptable for use in the areas in which it is installed. It is good to be aware of the fact that the mixture of flammable gas with oxygen has an optimum point where the combustion is most severe and leads to the highest explosion pressure. The two general approaches are: Several techniques of flame-proofing exist, and they are often used in combination: Equipment has flameproof gaps (max 0.006" (150m) propane/ethylene, 0.004" (100m) acetylene/hydrogen), Equipment can be installed in ANY housing provided to IP54.A 'Zener Barrier', opto-isolator or galvanic unit may be used to assist with certification. Various regulations use terms such as class, division, zone, and group to differentiate the various hazards. Examples are: production facilities in the food industry, chemical plants, oil & gas, and the pharmaceutical industry etc. The label will always list the class, division and may list the group and temperature code. The more hazardous the area to more safety measures have to be taken in order to prevent equipment becoming an effective source of ignition. It is created based on input from the Process Flow Diagrams, Piping & Instrumentation Diagrams and the Equipment Location Plan . This can be achieved by blanketing with nitrogen or carbondioxide. Temporary Refuge June 2019 In the United States, the most commonly followed system is the NEC (National Electric Code), while the rest of the world generally follows the IEC (International Electrotechnical Commission). Zone 1 is an area that is classified 'as a place in which an explosive atmosphere consisting of a mixture with air or flammable substances in the form of gas, vapours and mists is likely to occur occasionally during normal operation', whereas Zone 2 is an area that is classified 'as a place in which an explosive atmosphere consisting of a mixture The Zone Classification System is offered as an alternative to the Class and Division system. Zone 1 2. [4], Flammability of combustible liquids are defined by their flash-point. The NEMA enclosure rating or IP code may also be indicated, but it is usually independent of the Classified Area suitability. For dusts: Zone 20, Zone 21 and Zone 22. This was accompanied by electrically-initiated explosions of flammable gas such as fire damp (methane) and suspended coal dust. The basis for the classification into zones is the duration of the presence of the potentially explosive atmosphere: The longer it is present, the more critical the zone. September 2019 class correct, Motors, lighting, junction boxes, electronics, Equipment is very robust and components are made to a high quality, Equipment components are completely submerged in oil, Equipment components are completely covered with a layer of sand, powder or quartz, Equipment components of the equipment are usually encased in a resin type material. This value of this LOC differs per substance and depends also on the inert gas for achieving a low oxygen concentration. As a guide for Zone 0, this can be defined as over 1000 hours/year or >10% of the time. December 2021 When the concentration of gas or vapor is beneath the LEL the gas mixture is too lean to burn. . Such areas include a residence or office where the only risk of a release of explosive or flammable gas would be such things as the propellant in an aerosol spray. In the US, the National Electrical Manufacturers Association (NEMA) defines standards for enclosure types for a variety of applications. eg Production Area, area surrounding zone 0. NEC Div 1 Zone 1 Div 2 Zone 2Flammable during normal operation Most Safer Zone IEC Zone 0 DESRIPTIONHighly Flammable for long period DEFINITIONFlammable atmosphere present continuously (Typically 1000 hours / year). No long-term contract. But every hazardous area is different and each has specific requirements depending on the nature of the atmosphere and the elements that are present. The first thing to understand is that much like the metric vs imperial measuring systems, the United States uses its own methodology which differs from much of the world. Shown below is a summary of the applicable NEC Articles to reference to ensure the proper requirements are applied. Electric equipment depending on the protection techniques described by paragraph (g)(3)(i) of this section may not be suitable for use at temperatures lower than -20 C (-4 F) unless they are approved for use at lower temperatures. In an ordinary household this is of no concern, but if a flammable atmosphere is present, the arc might start an explosion. Equipment that is safe for the location shall be of a type and design that the employer demonstrates will provide protection from the hazards arising from the combustibility and flammability of vapors, liquids, gases, dusts, or fibers involved. Group II is for explosive gases (Zone 0, 1 and 2) and Group III is for explosive dusts (Zone 20, 21 and 22). Sources of such hazards include gases, vapors, dust, fibers, and flyings, which are combustible or flammable. June 2022 Therefore, it is very important to make sure that you are using a suitable luminaire for your application by choosing your fitting based on its suitability for the Zone in which it will be located. Whenever you are filling up your tank you are standing in a Zone 1 hazardous area. Zone 22 Zone 21 Zone20 A hazardous atmosphere formed by dust cloud in air is not likely to occur in . Zone 0 is an area in which an explosive atmosphere is present continuously for long periods of time or will frequently occur. 1910.307 (g) (2) A differentiation is made between gas Ex zones and dust Ex zones: Gas Ex zones are 0/1/2 and dust Ex zones are 20/21/22. Sources of The NEC Zone system was created to harmonize with IEC classification system, and therefore reduce the complexity of management. Note to paragraph (g)(5)(ii)(C) of this section: The National Electrical Code, NFPA 70, contains guidelines for determining the type and design of equipment and installations that will meet this provision. Locations shall be classified depending on the properties of the flammable vapors, liquids, or gases that may be present and the likelihood that a flammable or combustible concentration or quantity is present.