The simplest is to minimize the amount of electrical equipment installed in a hazardous location, either by keeping the equipment out of the area altogether, or by making the area less hazardous (for example, by process changes, or ventilation with clean air). 10/1/20 | For Dust this would be Zone 21. *unless risk assessment states a higher or lower category is required. Controls can be fitted to detect dangerous concentrations of hazardous gas, or failure of countermeasures. The minimum concentration of oxygen, necessary for the combustion to take place, is called the Limiting Oxygen Concentration. The Zone system has three levels of hazard for gas or dust where the Division system has two. Zone 1 2. August 2022 NFPA 70 NEC establishes area classifications based on Classes, Divisions and Groups that when combined delineate the hazardous conditions of a specific area. 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. In ambient conditions it is assured that oxygen is always present and thus not a factor that has to be incorporated within the hazardous area assessment. September 2020 November 2021 Zone 22 Zone 21 Zone20 A hazardous atmosphere formed by dust cloud in air is not likely to occur in . The colour of the luminaire body indicates the level of protection. Dn 2 - a Ce d e r . [12], International Electrotechnical Commission, Occupational Safety and Health Administration, National Electrical Manufacturers Association, "Hazardous Area Classification and Control of Ignition Sources", "Hazardous (Classified) Locations NEC Articles 500 through 517", https://en.wikipedia.org/w/index.php?title=Electrical_equipment_in_hazardous_areas&oldid=1134828101, ignitable concentrations of combustible dust can exist, under normal conditions, ignitable concentrations of combustible dust are unlikely to exist normally, ignitable fibers, or materials producing combustible flyings, are handled, manufactured or used, easily ignitable fibers are stored or handled. It uses the familiar Class/Division system and adapts the IEC/CENELEC Zones into it while maintaining NEC wiring methods and . 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. Note to paragraph (g)(5)(ii)(B) of this section: An example of such a required marking is "Class I, Zone 0, AEx ia IIC T6." Oil Immersion "o" -- This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. Sources of such hazards include gases, vapors, dust, fibers, and flyings, which are combustible or flammable. The Zone system for classifying hazardous locations used in NFPA 70 NEC, IEC 60079, and the Canadian Electrical Code indicates the level of probability that a flammable concentration of a hazardous substance may be present. Hazardous area classification. gas, vapours, mists and dusts). Zones 0, 1 and 2: Atmospheres with explosive gases and vapours (AS2380; AS/NZS/IEC 60079) Zone 0 Area The definition according to IEC60079-10-1 is "an area in which an explosive gas atmosphere is present continuously or for long periods or frequently". Have a think about it next time youre filling up! . For example, within the U.K. in the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) and in the U.S. in the Occupational Safety and Health Act of 1970 (OSHA). Each room, section, or area shall be considered individually in determining its classification. Classification of locations, testing and listing of equipment, and inspection of installation, is typically overseen by governmental bodies. April 2021 The flash-point is the temperature at which the material will generate sufficient quantity of vapor to form an ignitable mixture. Atmospheres containing non-conductive dust. NEGATIVE PRESSURE (equivalent to NEC Class I, Groups A and B), (equivalent to NEC Class II, Groups F and G), Group IIC is the most severe zone system gas group. Lets take a look at what defines each zone. Zone 1 - Explosive atmospheres are likely to occur. What are 'Dark Factories,' and Do They Really Exist? Q: Can I use a piece of equipment approved for use in a Division 1 hazardous location in a Division 2 hazardous location? The use of EPL and ATEX Category directly is an alternative for "s" marking. 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. January 2022 A spark or high heat must also be present. ESS Container according to ISO standard 80079 series. The information contained in this article is intended for general information purposes only and is based on information available as of the initial date of publication. Several protection strategies exist. For methane this is shown in the following figure. Area (mm2) CFD BS EN 60079-10-1:2009 1 5.0 5.0 0.0936 12.3 - 61.7 2 5.0 2.5 0.0326 6.17 - 30.8 TLS OFFSHORE CONTAINER The classification process requires the participation of operations, maintenance, safety, electrical and instrumentation professionals; and the use of process diagrams, material flows, safety data sheets, and other pertinent documents. Zone 0 Area The definition according to IEC60079-10-1 is "an area in which an explosive gas atmosphere is present continuously or for long periods or frequently". IEC 60079-10-1 covers classification of explosive gas atmospheres, and IEC 60079-10-2 explosive dust. March 2021 Marking "EEx d" in Accordance with EN 50 0 14 and 50 018 . Category 2 equipment may be used in zone 1 or zone 2 areas. Which system is preferred depends on the users preference, how the areas are classified, and the wiring system used. Equipment approved for use in Class I hazardous locations cannot be used in Class II hazardous locations. 5mm -750C Electrical Resistivity. As a result, all hazardous area equipment must be designed with hazardous area zone classifications in mind, as the zone governs the level of protection and precaution required. Equipment is pressurised to a positive pressure relative to the surrounding atmosphere with air or an inert gas, thus the surrounding ignitable atmosphere can not come in contact with energized parts of the apparatus. Informational Note No. The most standards and codes of practise for Hazardous Area Classification describe typical installations and work environments and their hazardous areas. . 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). This equipment is intended for use in Zone 1 (gases) or Zone 21 (dusts). As to the classification, they are the same. Ways to ensure this level of safety are non-arcing design and limitation of the temperature of the equipment. One of the hazards of working with flammable substances is an explosion, mostly hand in hand with fire. This is an important factor in the classification of hazardous areas. Zone 2 Explosive Mixtures not likely to occur /occur short duration in normal operation (lt10 Hrs/ Yr). 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. Industrial electrical equipment for hazardous area has to conform to appropriate parts of standard: IEC-60079 for gas hazards, and IEC-61241 for dust hazards. Class II combustible dusts are grouped into one of three (3) groups: E combustible metal dusts, F combustible carbonaceous dusts or G other combustible dusts. [3], Different explosive atmospheres have chemical properties that affect the likelihood and severity of an explosion. January 2021 It may exist because of repair, maintenance operations, or leakage. The equipment group . 2: For Group IIIC combustible dusts or metal combustible fibers/flyings, there shall only be Zone 20 or 21 locations. Fundamentally, for an explosion to take place, flammable or explosive gases, vapours, mists or dusts will be present. Accommodation Cabin . No. Zone 2. June 2020 Examples are: In another blog we, will explain how to perform Hazardous Area Classification according to the Standard EN-IEC 60079-10-1. For example, a socket outlet labeled EEx'de' might have a case made to EEx 'e' and switches that are made to EEx 'd'. Zone 0 is reserved for those areas continuously hazardous (e.g., inside a vented fuel tank), so other Division 1 areas would be classified as Zone 1. WATER TIGHTNESS Zone 0 is an area in which an explosive atmosphere is present continuously for long periods of time or will frequently occur. This article covers the requirements for the, Informational Note No. This temperature is used for classification for industry and technology applications.[6]. BATTERY ENERGY STORAGE SYSTEMBESS) A Zone 1 hazardous area is classified as a place in which an explosive atmosphere consisting of a mixture with air or flammable substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally. Temperature Control Where there is potential for an explosive atmosphere, special precautions are needed to prevent fires and explosions. Type of protection "n" is further subdivided into nA, nC, and nR. The IEC 60079 standard set has been adapted for use in Australia and New Zealand and is published as the AS/NZS 60079 standard set. The Regulations define 3 zones that can exist within a hazardous area: Zone 0 - A place in which an explosive atmosphere is present continuously or for long periods. And safety must be guaranteed in the case of two faults occurring independently of each other. Atmosphere containing a flammable gas, a flammable liquid produced vapor or a combustible liquid-produced vapor whose MESG is greater than 0.75 mm or MIC ratio is greater than 0.40 and less than 0.80 - such as carbon monoxide, ether, hydrogen sulfide, morphline, cyclopropane, ethyl, isoprene, acetaldhyde and ethylene or gases of equivalent hazard. Equipment in this category is intended for use in areas in which explosive atmospheres caused by gases, vapours, mists or air/dust mixtures are likely to occur occasionally. Pit will be considered as Zone 1. SPARTANs Zone 1 part code begins SPX, Zone 2 SPZ and industrial products having a SPI prefix. The Raytec SPARTAN range includes dedicated luminaires for both Zone 1 and Zone 2 areas as well as industrial applications. Informational Note No. 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 instances of areas within the same facility classified separately, Class I, Zone 2 locations may abut, but not overlap, Class I, Division 2 locations. . 6: For further information on electrical systems for hazardous (classified), Informational Note No. Click on the zone to learn more about the classification according to IEC 60079-10 standards. Entire Vapour space of storage tank. Zone 2 - Explosive atmospheres are unlikely to occur or present only infrequently and for a short period only. 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). The Hazardous Area Classification presents in this guide is based on the following items as reference: API: API RP 505 Recommended Practice for Classification of Locations for Electrical. July 2019 Whenever you are filling up your tank you are standing in a Zone 1 hazardous area. Those guidelines address electric wiring, equipment, and systems installed in hazardous (classified) locations and contain specific provisions for the following: wiring methods, wiring connections; conductor insulation, flexible cords, sealing and drainage, transformers, capacitors, switches, circuit breakers, fuses, motor controllers, receptacles, attachment plugs, meters, relays, instruments, resistors, generators, motors, lighting fixtures, storage battery charging equipment, electric cranes, electric hoists and similar equipment, utilization equipment, signaling systems, alarm systems, remote control systems, local loud speaker and communication systems, ventilation piping, live parts, lightning surge protection, and grounding. This is presented by the Lower Explosion Limit (LEL) of a substance. 10: For information on electrical resistance trace heating for hazardous (classified), Informational Note No. In the IEC standards hazardous areas are classified into zones based upon the frequency and duration of an explosive atmosphere. NFPA 70 NEC uses the familiar Class/Division system and has added an Americanized version of the International Electrochemical Commissions (IEC) IEC Zone system which maintains the NEC wiring methods and protection techniques. The last requirement for the explosion is the presence of an ignition source, like a spark or hot surface. THE CURRENT STANDARD . Atmospheres containing propane, acetone, benzene, butane, methane, petrol, hexane, paint solvents or gases and vapors of equivalent hazard. Division 1 and 2 Zone 0, 1 and 2 A (acetylene) IIC (acetylene & hydrogen) B (hydrogen) C (ethylene) IIB (ethylene) Substances characterization Consequences . A special standard for instrumentation is IEC/EN 60079-27, describing requirements for Fieldbus Intrinsically Safe Concept (FISCO) (zone 0, 1 or 2) (This special standard has been withdrawn, and has been partially replaced by: IEC/EN60079-11:2011 and IEC/EN60079-25:2010)[1], A special standard for instrumentation is IEC/EN 60079-27, describing requirements for Fieldbus Non-Incendive Concept (FNICO) (zone 2) (This special standard has been withdrawn, and has been partially replaced by: IEC/EN60079-11:2011 and IEC/EN60079-25:2010)[9]. Class I: hazardous because flammable gases or vapors are present in the air in quantities sufficient to produce explosive or ignitable mixtures: . Determining the Class, Division and Group or Zone and Group is critical to correctly applying the requirements for a given hazardous location. . 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. Areas with possible fire or explosion risks due to explosive atmospheres and/or mixtures - are called hazardous (or classified) locations or areas. The Zone system has wider use in the chemical and petrochemical industries. 15 4. How to perform Hazardous Area Classification? 0,1 or 2: II B: I: 1 or 2: C: Acetone Benzene Butane Hexane . Explosion Hazardous Areas are divided into zones according to risk probabilities. API RP 505, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Zone 0, Zone 1, and Zone 2 (as incorporated by reference in 250.198). This has been replaced by a European numerical system, as set out in directive 1999/92/EU implemented in the UK as the Dangerous Substances and Explosives Atmospheres Regulations 2002. . 1.1 Scope. API 500/505 mostly for onshore and offshore oil and gas applications. Non-hazardous or ordinary locations. Ambient Temperature (-20C to +40C if not marked) Establish Zone Based on "IEC 60079-10". area in which an explosive gas atmosphere is likely to occur occasionally in normal operation. The equipment housing may be sealed to prevent entry of flammable gas or dust into the interior. Zone defines thegeneral nature if it is a gas or dust and theprobabilityof hazardous material being present in an ignitable concentration in the surrounding atmosphere. December 2021 The process of determining the type and size of hazardous locations is called classification. For equipment provided with threaded entries for NPT threaded conduit or fittings, listed conduit, conduit fittings, or cable fittings shall be used. Other ignition sources can also be present, like static electricity. (between 0,1 and 10% of the time). Hazardous Area Classifications D103222X012 Product Bulletin 9.2:001 September 2019. Guidance on assessment of hazards is given in NFPA497 (explosive gas) and NFPA499 (dust). When working in or specifying equipment for use in hazardous environments, we see a lot of confusion in the industry regarding the different certifications and requirements. Outside of the United States, the IEC uses two different classifications: Gas & Vapor (Zones 0, 1, or 2) Dust (Zones 20, 21, or 22) Step 2: The next step is to determine how often the hazardous substance (s) is/are present. Note to paragraph (c)(2)(i) of this section: NFPA 70, the National Electrical Code, lists or defines hazardous gases, vapors, and dusts by "Groups" characterized by their ignitable or combustible properties. Class I hazardous locations are identified by zones as follows: * Zone 0 a location in which explosive gas atmospheres are present continuously or for long periods of time. 1: The term "Class I" was originally included as a prefix to, Informational Note No. Refrigerated Container April 2022 The CE mark is complemented with the Ex mark: A yellow-filled hexagon with the Greek letters (epsilon chi), followed by the Group, Category, and, if Group II, G or D (gas or dust).