No long-term contract. Within the European Union, these are defined by IEC/EN standards (IEC/EN 60079-10-1 or 2) as directed by ATEX. An oversimplification of this example is shown in Table 1. Area Classification - Hazardous Locations are classified by the likelihood of an ignitable concentration of combustible material being 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. The use of EPL and ATEX Category directly is an alternative for "s" marking. Atmosphere containing carbonaceous dusts, Atmosphere containing combustible dust not included in Group E & F - such as. Feedback From Clients The equipment group . 6: For further information on electrical systems for hazardous (classified), Informational Note No. What is an Explosion Protection Document? It is essential to know which zone you are working in, so that you can specify the most appropriate equipment. . 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). Zone 0/20: An area in which an explosive atmosphere is present continuously or for long periods or frequently. Fundamentally, for an explosion to take place, flammable or explosive gases, vapours, mists or dusts will be present. Many items of EEx rated equipment will employ more than one method of protection in different components of the apparatus. The choice of which standard to use for the hazardous area classification is something which is very important. 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. April 2021 Both external and internal temperatures are taken into consideration. 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. BATTERY ENERGY STORAGE SYSTEMBESS) It is created based on input from the Process Flow Diagrams, Piping & Instrumentation Diagrams and the Equipment Location Plan . Adapters shall be used for connection to conduit or NPT-threaded fittings. Informational Note No. Type of protection "n" is further subdivided into nA, nC, and nR. Identifying Zone 0, Zone 1, and Zone 2 Hazardous Areas. Shown below is a summary of the applicable NEC Articles to reference to ensure the proper requirements are applied. . Safety is ensured in the event of frequently occurring disturbances or equipment faults which normally have to be taken into account. POSITIVE PRESSURE The temperature marking may not exceed the ignition temperature of the specific gas or vapor to be encountered. Equipment shall be marked in accordance with paragraph (g)(5)(ii)(A) and (g)(5)(ii)(B) of this section, except as provided in (g)(5)(ii)(C). Directly adjacent on the label one will find the mark of the listing agency. International Electrotechnical Committee (IEC) Hazardous Area Classification. But every hazardous area is different and each has specific requirements depending on the nature of the atmosphere and the elements that are present. 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. * 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. Choose the right method for Hazardous Area Classification! 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. April 2022 The key difference between Divisions and Zones relate to terminations. There are several ways of how to perform hazardous area classification, all described in several standards or codes of practise. The inductance of the signal bell coils, combined with breaking of contacts by exposed metal surfaces, resulted in sparks, causing an explosion. It is obvious to use those standards within these industries. These generally give rise to areas classied as Zones 0, 1, and 2 respectively. Refrigerated NFPA 70 NEC Classes, Divisions and Groups. In some cases, the hazardous atmosphere is present all the time, or for long periods. 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. Flour, wood/sawdust, plastic dust). Flour, wood/sawdust, plastic dust), IIC Conductive dusts (eg. Equipment that is listed for a Zone 1 location may be installed in a Zone 2 location of the same gas or vapor. 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. December 2013, All What Are All Those Gadgets On A Multitool? Class I: hazardous because flammable gases or vapors are present in the air in quantities sufficient to produce explosive or ignitable mixtures: . 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). . Not only are hazardous areas classified by Class (nature of the hazardous material,) and Division . Zone 1 - Explosive atmospheres are likely to occur. December 2022 Equipment is placed into protection level categories according to manufacture method and suitability for different situations. This process is called hazardous area classification. Explosion-proofing designs equipment to contain ignition hazards, prevent entry of hazardous substances, and, contain any fire or explosion that could occur. Zones compares to classes and divisions in the Class/Division system. (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. If you require more information on the different variants in the SPARTAN range, or you would like to discuss your application in more detail, you can call us on +44 (0) 1670 520055 or send an email to sales@raytecled.comwhere we will happily answer any questions you have. The types of protection are subdivided into several sub classes, linked to EPL: ma and mb, px, py and pz, ia, ib and ic. Whenever you are filling up your tank you are standing in a Zone 1 hazardous area. Zone type (0/1/2/ 20/21/ 22) Zone extent. See Figure S-1 for an explanation of this marking. Beside sufficient fuel, also sufficient oxygen is needed for combustion of the mixture. The specific hazardous materials within each group and their automatic ignition temperatures can be found in Article 500 of the National Electrical Code and in NFPA 497. Zone 2. 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. 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. 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. Equipment shall be approved not only for the class of location, but also for the ignitable or combustible properties of the specific gas, vapor, dust, or fiber that will be present. 1994-2020, W.W. Grainger, Inc. All Rights Reserved. . Readers with specific questions should refer to the applicable standards or consult with an attorney. (between 0,1 and 10% of the time). October 2018 Equipment marked as suitable for IIB is also suitable for IIA but NOT for IIC. Zone 0: flammable atmosphere highly likely to be present - may be present for long periods or even continuously . Dust or other small particles suspended in air can explode. The surface of a high pressure steam pipe may be above the autoignition temperature of some fuel-air mixtures. Division II Comprising of Area Same as Zone 2. Upon detection, appropriate action is automatically taken, such as removing power, or providing notification. Standards for electrical installations have been established and are governed by a variety of organizations throughout the world to ensure safe electrical systems in hazardous locations. Non-hazardous or ordinary locations. Reefer Container For liquids, gases and vapours: Zone 0, Zone 1 and Zone 2. It is always balancing between not defining such areas too large (with highly costs for prevention of ignition sources) or too small (unsafe situations). Photo 2. Raytec do not currently offer any lighting solutions for Zone 0. Refrigerated Container 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. These areas are classified solely for the purpose of ensuring the safe and proper specification and installation of electrical/electronic equipment. Other ignition sources can also be present, like static electricity. This page was last edited on 20 January 2023, at 22:32. . The substance referred to by classhas a low probability of producing an explosive or ignitable mixture and is present only during abnormal conditions for a short period of time - such as a container failure or system breakdown. The last requirement for the explosion is the presence of an ignition source, like a spark or hot surface. [10][11] Some of these are specifically for hazardous locations: All equipment certified for use in hazardous areas must be labelled to show the type and level of protection applied. 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). 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". In order to understand hazardous area classification it is important to understand which factors contribute to the occurrence of an explosion. Table 1. Definition of hazardous area zones (AS/NZS 60079.10): Zone 0 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. When equipment must be placed in a hazardous location, it can be designed to reduce the risk of fire or explosion. 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. 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. 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. Each room, section, or area shall be considered individually in determining its classification. October 2021 Zone 1 is an area in which an explosive atmosphere is likely to occur occasionally in normal operation. Laboratory Container Is intended for us in Zone 2 (gases) or Zone 22 (dusts). 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. 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. lk) are places where fire or explosion hazards may exist. Explosions can cause significant damage along with severe injury or worse loss of life. Area which are not devided into Atex zones, are called non-hazardous area's. Container Accessories 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. With the advent of electric power, electricity was introduced into coal mines for signaling, illumination, and motors. Examples are: In another blog we, will explain how to perform Hazardous Area Classification according to the Standard EN-IEC 60079-10-1. Zone 0 is an area in which an explosive atmosphere is present continuously for long periods of time or will frequently occur. A list must be drawn up of every explosive material that is on the refinery or chemical complex and included in the site plan of the classified areas. These ways of protection are specified in detail within several IEC standards (IEC 60079 series) for electrical equipment. Zone 1: An area in which an explosive atmosphere is likely to occur in normal operation. When the concentration of methane is beneath the LEL, an explosion cannot occur, even when an ignition source is present. So a zone 0 is the most hazardous zone and a zone 2 is a less hazardous zone. In the United Kingdom, Sira and Baseefa are the most well known such bodies. A60 January 2022 A high level of protection is ensured. But when we take a closer look at the graph and table, we can conclude that any explosion, can easily lead to severe damage. 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. July 2022 THE PRODUCTS YOU NEED, It may exist because of repair, maintenance operations, or leakage. 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. In the US, the independent National Fire Protection Association (NFPA) publishes several relevant standards, and they are often adopted by government agencies. Often an area classification plan view is provided to identify equipment ratings and installation techniques to be used for each classified area.
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