". ethanol, methane or hydrogen. In this system, two bare wires were run along the length of a drift, and any miner desiring to signal the surface would momentarily touch the wires to each other or bridge the wires with a metal tool. A: Yes. The substance referred to by classhas a high probability of producing an explosive or ignitable mixture due to it being present continuously, intermittently, or periodically or fromthe equipment itself under normal operating conditions. Group II is for explosive gases (Zone 0, 1 and 2) and Group III is for explosive dusts (Zone 20, 21 and 22). For specific industries, the specific codes for that industry are important to use. 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. In the US, the National Electrical Manufacturers Association (NEMA) defines standards for enclosure types for a variety of applications. Areas with possible fire or explosion risks due to explosive atmospheres and/or mixtures - are called hazardous (or classified) locations or areas. 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. 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. 2: This classification includes, Informational Note No. In effect it is any method which can be shown to have the required degree of safety in use. Examples are: In another blog we, will explain how to perform Hazardous Area Classification according to the Standard EN-IEC 60079-10-1. In an ordinary household this is of no concern, but if a flammable atmosphere is present, the arc might start an explosion. When equipment must be placed in a hazardous location, it can be designed to reduce the risk of fire or explosion. The minimum concentration of oxygen, necessary for the combustion to take place, is called the Limiting Oxygen Concentration. . Non-hazardous or ordinary locations. Standards and regulations exist to identify such locations, classify the hazards, and design equipment for safe use in such locations. In Europe the label must show the CE mark and the code number of the certifying/notified body). area in which an explosive gas atmosphere is present continuously, or for long periods, or frequently (more than 10% of the time). Directly adjacent on the label one will find the mark of the listing agency. The following Equipment Groups and Categories are applicable: Equipment in this category is only intended for use in the underground areas of mines, as well as those areas of surface installations of such mines endangered by firedamp and/or combustible dusts. Each chemical gas or vapour used in industry is classified into a gas group. Ways to ensure this level of safety are non-arcing design and limitation of the temperature of the equipment. Comparisons between the two systems are not easily accomplished. Category 1 equipment may be used in zone 0, zone 1 or zone 2 areas. according to ISO standard 80079 series. And there are three corresponding zones for dust: Zone 20, Zone 21 and Zone 22. Magnesium, Titanium), IIB Nonconductive dusts (eg. That is why the use of mobile phones on petrol forecourts are banned. 1) MESG (Maximum Experimental Safe Gap) - The maximum clearance between two parallel metal surfaces that has been found under specified test conditions to prevent an explosion in a test chamber from being propagated to a secondary chamber containing the same gas or vapor at the same concentration. The key difference between Divisions and Zones relate to terminations. Choose the right method for Hazardous Area Classification! Vertical. Which system is preferred depends on the users preference, how the areas are classified, and the wiring system used. Zone 2. Equipment construction is such that it can withstand an internal explosion and provide relief of the external pressure via flamegap(s) such as the labyrinth created by threaded fittings or machined flanges. NFPA 70 NEC Articles 500 through 503 cover the requirements for electrical/electronic equipment and wiring for all voltages in Class I, Divisions 1 and 2; Class II, Divisions 1 and 2; and Class III, Divisions 1 and 2 locations. Enclosures can be pressurized with clean air or inert gas, displacing any hazardous substance. 11: For information on electric skin effect trace heating for hazardous (classified), Informational Note No. July 2022 So the following conditions must be met for an explosion to occur: Represented by the following explosion triangle. This is an important factor in the classification of hazardous areas. Atmosphere containing carbonaceous dusts, Atmosphere containing combustible dust not included in Group E & F - such as. 0. It may exist because of repair, maintenance operations, or leakage. 3: For further information on the classification of, Informational Note No. June 2020 Hazardous area classification. Locations are thus classified by type and risk of release of gas, vapor, or dust. NEGATIVE PRESSURE How to perform Hazardous Area Classification? There are three zones for gas: Zone 0, Zone 1 and Zone 2. ESS Container But beside electrical equipment also mechanical equipment must be Ex certified, e.g. A: No. For equipment with metric threaded entries, such entries shall be identified as being metric, or listed adaptors to permit connection to conduit of NPT-threaded fittings shall be provided with the equipment. The choice of which standard to use for the hazardous area classification is something which is very important. June 2022 [1] NEC article 500 describes the NEC Division classification system, while articles 505 and 506 describe the NEC Zone classification system. March 2021 Type of protection "n" is further subdivided into nA, nC, and nR. These areas only become hazardous in case of an accident or some unusual operating condition. A hazardous area classification drawing (also known as an area classification drawing) outlines the classifications of areas where flammable liquids, gasses or vapors are handed, processed or stored. * 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. 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. Two possible classifications are described, in Section 18 (Zones), and Appendix J (Divisions). . of The last requirement for the explosion is the presence of an ignition source, like a spark or hot surface. In Europe the ATEX 114 Directive (2014/34/EU) is applicable to equipment that is used in hazardous area's. Copryright 2023 Springer Controls Company . September 2019 The required protection level is linked to the intended use in the zones described below: The equipment category indicates the level of protection offered by the equipment. Zone type (0/1/2/ 20/21/ 22) Zone extent. Beside sufficient fuel, also sufficient oxygen is needed for combustion of the mixture. Australia and New Zealand use the same IEC-60079 standards (adopted as AS/NZS60079), however the CE mark is not required. 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. Container Standards 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] 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. 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. Since the changes to the code, hazardous locations with gases or vapors (Class I) present can be reclassified as Zone 0, 1 or 2. In general, all types of equipment installed within the hazardous area shall be . November 2019 ignitable concentrations of dust, fibers, or flyings are present for long periods of time, ignitable concentrations of dust, fibers, or flyings are likely to exist under normal conditions, ignitable concentrations of dust, fibers, or flyings unlikely to exist under normal conditions, Metal dusts, such as magnesium (Division 1 only), Carbonaceous dusts, such as carbon & charcoal, Non-conductive dusts, such as flour, grain, wood & plastic, Ignitible fibers/flyings, such as cotton lint, flax & rayon, Ignitible fibers or flyings, such as cotton lint, flax & rayon. An area where combustible dusts or ignitable fibers and flyings are present continuously or for long periods of time. Atmosphere containing a flammable gas, a flammable liquid produced vapor, or a combustible liquid produced vapor mixed with air that may burn or explode, having either a MESG (Maximum Experimental Safe Gap)1) value less than or equal to 0.45 mm or aMIC (Minimum Igniting Current)2) ratio less than or equal to 0.40 - such as hydrogen or fuel and combustible process gases containing more than 30% hydrogen by volume - or gases of equivalent hazard such as butadiene, ethylene oxide, propylene oxide and acrolein. A: When comparing Divisions and Zones, Division 2 is equivalent to Zone 2, but Division 1 is equivalent to either Zone 0 or 1. Ex s is a coding referenced in IEC 60079-0. Safe for the hazardous (classified) location. The above groups are formed in order of how explosive the material would be if it was ignited, with IIC being the most explosive zone system gas group and IIA being the least. Electrical equipment can and does cause fires and/or explosions in certain atmospheres. Note to paragraph (c)(3) 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 requirement. Carbon monoxide, ether, hydrogen sulfide, . As to the classification, they are the same. Equipment that is listed for a Zone 1 location may be installed in a Zone 2 location of the same gas or vapor. For methane this is shown in the following figure. 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 inductance of the signal bell coils, combined with breaking of contacts by exposed metal surfaces, resulted in sparks, causing an explosion. Hazardous Environment Classifications: NEC vs IEC, IEC (International Electrotechnical Commission), Group E Metal dusts (eg. Wide known is that al electrical equipment within hazardous areas must be Ex certified for use in the appropriate hazardous area (zone or class/division). lk) are places where fire or explosion hazards may exist. POSITIVE PRESSURE Ignition sources can be divided in 13 categories (acc. This value of this LOC differs per substance and depends also on the inert gas for achieving a low oxygen concentration. 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 . Beside the Lower Explosion Limit, each substance also has an Upper Explosion Limit (UEL). The temperature marking may not exceed the ignition temperature of the specific gas or vapor to be encountered. Ex Zone. 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. When the concentration of gas or vapor is beneath the LEL the gas mixture is too lean to burn. Temporary Refuge (TR) Shelter February 2019 Coal mines, grain mills, elevators, and similar facilities likewise present the risk of a clouds of dust. 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 Zone 22 Zone 21 Zone20 A hazardous atmosphere formed by dust cloud in air is not likely to occur in . 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. Explosions can cause significant damage along with severe injury or worse loss of life. An oversimplification of this example is shown in Table 1. February 2023 October 2018 Classification of locations, testing and listing of equipment, and inspection of installation, is typically overseen by governmental bodies. Entire Vapour space of storage tank. Zone 1 an area in which an explosive gas-air mixture is likely to occur in normal operating conditions. Atmospheres containing combustible flyings. February 2021 The relation between that system and de zone classification system is clarified within the following table (only for gases and liquids are displayed, not for dusts and fibers). Guidance on assessment of hazards is given in NFPA497 (explosive gas) and NFPA499 (dust). For explosion hazards caused by flammable liquids or gases, the following zones are defined: So a zone 0 is the most hazardous zone and a zone 2 is a less hazardous zone. Atmospheres containing ethylene, propylene oxide, ethylene oxide, butadiene, cyclopropane, ethyl ether, or gases and vapors of equivalent hazard. 1. 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. Often an area classification plan view is provided to identify equipment ratings and installation techniques to be used for each classified area. [4], Flammability of combustible liquids are defined by their flash-point. >> NEC: Class II, Division 1, Group F. | IEC: Zone 20, Group IIC. Refrigerated Area's are divided into zones. 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. 2) MIC (Minimum Igniting Current) Ratio - The ratio of the minimum current required from an inductive spark discharge to ignite the most easily ignitable mixture of a gas or vapor, divided by the minimum current required from an inductive spark discharge to ignite methane under the same test conditions. . Category 3 equipment may only be used in zone 2 areas. Temperature classification, except for intrinsically safe apparatus. Q: Can I use a piece of equipment approved for use in a Division 1 hazardous location in a Division 2 hazardous location? Q: Are Divisions and Zones equivalent to one another? Subscribe 6.9K views 2 years ago Oil and Gas Zone Classifications: A) Hazardous Area Classification It's cable reimagined No DVR space limits. 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. A hazardous area can be defined as any location where there is risk of an explosion. This means that the electrical equipment is safe for use within these area by applying special protection strategies. Zones 1 or 2. In order to understand hazardous area classification it is important to understand which factors contribute to the occurrence of an explosion. . the inside of tank truck or the interior of a dust filter). Motors, lighting, junction boxes, electronic equipment, This method, being by definition special, has no specific rules. Controls can be fitted to detect dangerous concentrations of hazardous gas, or failure of countermeasures. These are typically process areas where gases are more likely to be present. So yes, it is important to choose the right model and always wonder what am I assessing?. In this article we will look at what defines Zone 0, Zone 1 and Zone 2 hazardous area classifications and the considerations for specifying lighting into each area. Well recognized and clear IEC Standard IEC 60079-10-2:2015 Hazardous Area Classification for explosive dusts Significant influence on spending's for safety . Flour, wood/sawdust, plastic dust). When comparing Divisions and Zones, Division 2 is equivalent to Zone 2, but Division 1 is equivalent to either Zone 0 or 1. 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. . These areas only become hazardous in case of an accident or some unusual operating condition. August 2022 Explosion protection must be ensured during normal operation. 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. So for an explosion there must be enough fuel. . Dry Container Workshop Container, Intelligent pressurised container | MUD logging cabin, Battery energy storage system (BESS) container, Laboratory container | workshop container | Equipment containers, Temporary refuge shelter | Toxic gas refuge | Safe haven, Offshore accommodation cabin | office container, Reefer container | Refrigerated container, Intelligent waste water treatment container, IDENTIFYING ZONE 0, ZONE 1, AND ZONE 2 HAZARDOUS AREAS, Temporary refuge (TR) shelter, toxic gas refuge (TGR), Containerised waste water treatment plant. This rapid expansion of volume is caused by the combustion of a fuel, like e.g. Class 1/Div 2 ATEX Zone 2 Computers. Protecting against fire and explosion is of interest for both personnel safety as well as reliability reasons. Groups A, B, C, and D are for gases (Class I only). That flammable gas or vapor . hazardous areas as the following: An area where a potential hazard (e.g., a fire, an explosion, etc.) Hazardous Area Classifications D103222X012 Product Bulletin 9.2:001 . For Zone 1 applications, Pyroban uses . As mentioned, the first important step of achieving a safe work environment in relation to explosion safety is to identify and classify those areas, where a concentration of flammable gases or vapors within the flammable range can be present. Hazardous Area Classification (HAC) is as follows: Definitions of hazardous area are different as per IEC and NEC. Division defines the probability of the hazardous material being present in an ignitable concentration in the surrounding atmosphere. In Europe and the rest of the world - but also more and more in North America - the Zone system is used. 14 4. This concentration is substance specific and lies normally somewhere between the LEL and UEL. Entire Vapour space of storage tank. The groups also indicate how much energy is required to ignite the material by energy or thermal effects, with IIA requiring the most energy and IIC the least for zone system gas groups. Equipment used in hazardous area must comply to certain Ex standards. Zone Hazardous Location 2 Table of . Each room, section, or area shall be considered individually in determining its classification. Explosion Hazardous Areas are divided into zones according to risk probabilities. For dusts: Zone 20, Zone 21 and Zone 22. [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. For gases, vapours and mists the zone classifications are recognised as Zone 0, Zone 1 and Zone 2 areas. 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. IEC 60079-10-1 covers classification of explosive gas atmospheres, and IEC 60079-10-2 explosive dust. Offshore Accommodation Module Zone 1 - Explosive atmospheres are likely to occur. 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. What is an Explosion Protection Document? These generally give rise to areas classied as Zones 0, 1, and 2 respectively. So it is quite obvious that explosions should be prevented as much as possible and still work has to be done to achieve this. Gas a. October 2021 6: For further information on electrical systems for hazardous (classified), Informational Note No. . 1.1.2 This recommended practice provides information on specific flammable gases and vapors, flammable liquids . Horizontal. You will find this equipment in paint factories, a warehouse or around a bag dump station. 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. Marking "EEx d" in Accordance with EN 50 0 14 and 50 018 . Area classification is not simply intended to identify hazardous areas on process plants where design has already been completed using only operational and economic factors as influence,. The Zone system has wider use in the chemical and petrochemical industries. May 2021 This is exactly defined as the limiting concentration of oxygen below which combustion is not possible, independent of the concentration of fuel. (1) Zone 0. These would be then labeled with each of the individual methods. IECEx Karandikar Certification Group defines thetypeof hazardous material and partly thelocationof the surrounding atmosphere . Category 2 equipment may be used in zone 1 or zone 2 areas. When the concentration of methane is beneath the LEL, an explosion cannot occur, even when an ignition source is present. ), Group F Carbon-based (eg. 5mm -750C Electrical Resistivity. SEWAGE TREATMENT Is intended for us in Zone 2 (gases) or Zone 22 (dusts). Google use cookies for serving our ads and handling visitor statistics. The a subdivisions have the most stringent safety requirements, taking into account more than one independent component faults simultaneously. Zone 2 hazardous areas are typically storage areas but can also be process areas. The escaping (hot) gases must sufficiently cool down along the escape path that by the time they reach the outside of the enclosure not to be a source of ignition of the outside, potentially ignitable surroundings. Container Accessories In the United States, the NEC uses 2 different classifications: Therefor Hazardous Area Classification (HAC) is the first important step in achieving an explosion safe installation or work environment. Hazards in this group gas can be ignited very easily indeed. This equipment is intended for use in Zone 1 (gases) or Zone 21 (dusts). - 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 . Recommendat ions. Class defines the general nature (or properties) of the hazardous material in the surrounding atmosphere. Zone 1 - A place in which an explosive atmosphere is likely to occur in normal operation occasionally 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.