See below for further details: Division system sample marking March 2021 December 2021 The International Electrotechnical Commission publishes the 60079 series of standards[2] which defines a system for classification of locations, as well as categorizing and testing of equipment designed for use in hazardous locations, known as "Ex equipment". POSITIVE PRESSURE These would be then labeled with each of the individual methods. Specific types of protection being used will also be marked. Zone 1 is an area in which an explosive atmosphere is likely to occur occasionally in normal operation. according to ISO standard 80079 series. Zone 22 Zone 21 Zone20 A hazardous atmosphere formed by dust cloud in air is not likely to occur in . The use of EPL and ATEX Category directly is an alternative for "s" marking. Zone 0Ignitable concentrations of flammable gases or vapors which are present continuously or for long periods of time. There are four zones in the IEC classification system: Zone 0: An area in which an explosive atmosphere is present continuously or for long periods. Both external and internal temperatures are taken into consideration. Informational Note No. The design of the equipment must ensure protection, even in the event of rare incidents relating to the equipment. As a guide for Zone 0, this can be defined as over 1,000 hours/year or >10% of the time. 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. 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. Hazardous classified locations are areas where the possibility of fire or explosion hazards may exist under normal or abnormal conditions because of the presence of flammable, combustible or ignitable gases, vapors, liquids, dust, or fibers/flyings. Zone 1 fittings are supplied as silver, Zone 2 as dark grey and industrial fittings as white. NFPA 497: Recommended Practice for the Classification of Flammable Division 2 is equivalent to Zone 2, while Division 1 is either Zone 0 or 1. [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. 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). Explosions can cause significant damage along with severe injury or worse loss of life. ethanol, methane or hydrogen. PDF Australian Hazardous Area Selection Chart - Frsa Hazardous Area Training: 500 505 API RP - OCS Group The NEC Zone system was created to harmonize with IEC classification system, and therefore reduce the complexity of management. Marking "EEx d" in Accordance with EN 50 0 14 and 50 018 . November 2021 To make this even easier to understand, take a look at the diagram of a typical petrol station below where we have identified the areas that are classified as Zone 0, Zone 1 and Zone 2. 10: For information on electrical resistance trace heating for hazardous (classified), Informational Note No. So it is quite obvious that explosions should be prevented as much as possible and still work has to be done to achieve this. Quick Tips #124.1. In Europe the label must show the CE mark and the code number of the certifying/notified body). If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. The minimum concentration of oxygen, necessary for the combustion to take place, is called the Limiting Oxygen Concentration. One of the hazards of working with flammable substances is an explosion, mostly hand in hand with fire. Identifying Zone 0, Zone 1, and Zone 2 Hazardous Areas Sources of Magnesium, Titanium), IIB Nonconductive dusts (eg. Vertical. Cookies are only used in the browser to improve user experience. 1.1.2 This recommended practice provides information on specific flammable gases and vapors, flammable liquids . Zone 20, 21, and 22 Locations for Combustible Dusts or - UpCodes To prevent explosions from happening in harsh environments whereby flammable gases or combustible dusts are present directives and guidelines are put in place to protect both the public, workforce, and environment. Although OSHA does not provide a definition of group classifications in 29 CFR 1910.307 or 399 they do provide a note under 29 CFR 1910.307(c)(1) that states: NFPA 70, the National Electrical Code, lists or defines hazardous gases, vapors, and dusts by Groups characterized by their ignitable or combustible properties. To meet OSHAs marking requirement, the marking must include the hazardous group the equipment is approved to operate in. The following content is only related to flammable substances and not to pyrotechnic substances or other instable substances, among those who can decompose. Atex Zone Classification | Atex Zone 1 vs. Zone 2 | Atex Zones - Hoist UK Class 1 / Division 2 and ATEX Zone 2 Explained - Assured Systems Upon detection, appropriate action is automatically taken, such as removing power, or providing notification. 2: Through the exercise of ingenuity in the layout of electrical installations for hazardous (classified), Refrigerant machinery rooms that contain ammonia refrigeration systems and are equipped with adequate mechanical ventilation that operates continuously or is initiated by a detection system at a concentration not exceeding 150 ppm shall be permitted to be classified as "unclassified". A 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. PROCESS OF CONTAINER September 2019 The autoignition temperature is the lowest temperature at which the substance will ignite without an additional heat or ignition source (at atmospheric pressure). If equipment is marked, for example, Ex e II T4 then it is suitable for all subgroups IIA, IIB and IIC. Atmosphere containing carbonaceous dusts, Atmosphere containing combustible dust not included in Group E & F - such as. 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. It may exist because of repair, maintenance operations, or leakage. PDF Hazardous Area Classification - dust atmospheres - IECEx less than 0.45 mm or MIC ratio is less than 0.40. Each room, section, or area shall be considered individually in determining its classification. Not only are hazardous areas classified by Class (nature of the hazardous material,) and Division . >> For Gas Vapor this would be Zone 1. Unlike ATEX which uses numbers to define the safety "Category" of equipment, namely (1,2 3), the IEC continued to utilise the method used for defining the safe levels of intrinsic safety namely "a" for zone 0, "b" for zone 1 and "c" for zone 2 and apply this Equipment Level of Protection to all equipment for use in hazardous areas since 2009. area in which an explosive gas atmosphere is present continuously, or for long periods, or frequently (more than 10% of the time). Note to paragraph (g)(4) of this section: Low ambient conditions require special consideration. But every hazardous area is different and each has specific requirements depending on the nature of the atmosphere and the elements that are present. Comparisons between the two systems are not easily accomplished. The last condition for an explosion is the presence of an effective ignition source in the direct contact with the fuel/air mixture. d : HA - ha ea OA - oa Area classification - Divisions vs. zones Continuous hazard Intermittent hazard Hazard under abnormal conditions Zone 0 Zone 1 Zone 2 Division 1 Division 1 Division 2 Hazardous locations - CEC classifications Class I In order to understand hazardous area classification it is important to understand which factors contribute to the occurrence of an explosion. See Figure S-1 for an explanation of this marking. November 2022 The more hazardous the area to more safety measures have to be taken in order to prevent equipment becoming an effective source of ignition. | For Dust this would be Zone 21. Recommendat ions. Some equipment in Division 2 areas do not require a specific label, such as standard 3 phase induction motors that do not contain normally arcing components. These areas are in North America (United States and Canada) historically classified with the Class/Division system. October 2019 In effect it is any method which can be shown to have the required degree of safety in use. Group define the type of hazardous material and (partly) the location of the surrounding atmosphere. Get more great content like this sent to your inbox. The definition of the hazardous area zones represent the likelihood of hazardous gas, dust or other hazards being present in a working area. Safety is ensured in the event of frequently occurring disturbances or equipment faults which normally have to be taken into account.