We will go deeper into ignition assessments in another blog. FREEZER July 2022 Hazardous area classification is a rigorous method of determining where an explosive environment may be present. THE PRODUCTS YOU NEED, This is presented by the Lower Explosion Limit (LEL) of a substance. Category 2 equipment may be used in zone 1 or zone 2 areas. The choice of which standard to use for the hazardous area classification is something which is very important. Encapsulation "m" -- This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. Motors, lighting, junction boxes, electronic equipment, This method, being by definition special, has no specific rules. 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. Shown below is a summary of the applicable NEC Articles to reference to ensure the proper requirements are applied. The surface of a high pressure steam pipe may be above the autoignition temperature of some fuel-air mixtures. Within the European Union, these are defined by IEC/EN standards (IEC/EN 60079-10-1 or 2) as directed by ATEX. October 2018 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. All threaded conduit shall be threaded with an NPT (National (American) Standard Pipe Taper) standard conduit cutting die that provides -in. 6: For further information on electrical systems for hazardous (classified), Informational Note No. 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. 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. The four steps involved in hazardous area classification are: Determine the type of hazard or "class" that might be presentcombustible gas (Class I), combustible dust (Class II), or fibers (Class III). Ex s is a coding referenced in IEC 60079-0. Have a think about it next time youre filling up! February 2022 RP 505 is referred to as the zone system. For gases, vapours and mists the zone classifications are recognised as Zone 0, Zone 1 and Zone 2 areas. 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 . When the concentration of methane is beneath the LEL, an explosion cannot occur, even when an ignition source is present. October 2021 Independent test housesNotified Bodiesare established in most European countries, and a certificate from any of these will be accepted across the EU. We don't collect information from our users. 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. ADNOC October 2020 A high level of protection is ensured. Zones compares to classes and divisions in the Class/Division system. Equipment provided with threaded entries for field wiring connection shall be installed in accordance with paragraph (g)(2)(iv)(A) or (g)(2)(iv)(B) of this section. Zone 1 fittings are supplied as silver, Zone 2 as dark grey and industrial fittings as white. Explosion protection must be ensured during normal operation. 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. Class I: hazardous because flammable gases or vapors are present in the air in quantities sufficient to produce explosive or ignitable mixtures: . The Zone system of hazardous area classification, defines the probability of the hazardous material, gas, or dust, being present in sufficient quantities that can generate explosive or ignitable mixtures. Terminology for both hazards and protective measures can vary. Readers with specific questions should refer to the applicable standards or consult with an attorney. 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. Zone 0: flammable atmosphere highly likely to be present - may be present for long periods or even continuously . 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. Feedback From Clients Directly adjacent on the label one will find the mark of the listing agency. So, it is good to know that when a flammable substance concentration exceeds the LEL, it will not automatically lead to an explosion with the highest Pmax. In some cases, the hazardous atmosphere is present all the time, or for long periods. The overpressure is monitored, maintained and controlled. 14 4. 11: For information on electric skin effect trace heating for hazardous (classified), Informational Note No. Refrigerated Container Often an area classification plan view is provided to identify equipment ratings and installation techniques to be used for each classified area. 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. For dusts: Zone 20, Zone 21 and Zone 22. September 2020 March 2021 The Zone Classification System is offered as an alternative to the Class and Division system. This value of this LOC differs per substance and depends also on the inert gas for achieving a low oxygen concentration. 5: For further information on ventilation, see NFPA 30-2018, Informational Note No. 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. Class defines the type of explosive or ignitable substances which are present in the atmosphere. Zone type (0/1/2/ 20/21/ 22) Zone extent. The conduit shall be made wrench tight to prevent sparking when fault current flows through the conduit system and to ensure the explosionproof or flameproof integrity of the conduit system where applicable. In an industrial plant, such as a refinery or chemical plant, handling of large quantities of flammable liquids and gases creates a risk of exposure. January 2022 . Group is divided in three groups where Group I is reserved for mining locations. One of the hazards of working with flammable substances is an explosion, mostly hand in hand with fire. Click on the zone to learn more about the classification according to IEC 60079-10 standards. Drop Test 7: For further information on application of electrical, Informational Note No. CUTTING SKIPS Hazardous areas are classified into 3 zones based upon the frequency of the occurrence and duration of an explosive gas atmosphere, as follows: Zone 0 Area in which an explosive gas atmosphere is present continuously or for long periods or frequently. Temperature Control The flash point determines if an area needs to be classified. Class II, Div 2 Class III, Div 1 nR 3G Zone 2 Gc Class III, Div 2 Pressurised Room px 60079-13 2G Zone 1 Gb Zone 21 Db 2D Pressurised Room FM3611 NFPA 496 Class I, Div 1 Class I, Div 2 Class II, Div 1 Class II, Div 2 py 2G Zone 1 Gb pz 3G Zone 2 Gc Zone 22 Dc 3D pv Non-hazardous Gb/GC Optical Radiation op sh 60079-28 1G Zone 0 Ga Zone 20 Da 1D . For equipment provided with threaded entries for NPT threaded conduit or fittings, listed conduit, conduit fittings, or cable fittings shall be used. These areas only become hazardous in case of an accident or some unusual operating condition. August 2018 1910.307 - Hazardous (classified) locations. Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications! 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. Zone 0Ignitable concentrations of flammable gases or vapors which are present continuously or for long periods of time. Table 1. Temporary Refuge The design of the equipment must ensure protection, even in the event of rare incidents relating to the equipment. Laboratory Container The housing may be strong enough to contain and cool any combustion gases produced internally. The last requirement for the explosion is the presence of an ignition source, like a spark or hot surface. Typical gas hazards are from hydrocarbon compounds, but hydrogen and ammonia are also common industrial gases that are flammable. For example, a socket outlet labeled EEx'de' might have a case made to EEx 'e' and switches that are made to EEx 'd'. Area classification documentations are reviewed and updated to reflect process changes. No. POSITIVE PRESSURE 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. >> NEC: Class II, Division 1, Group F. | IEC: Zone 20, Group IIC. Although every application is different, for the ease of monitoring and specification each hazardous area is classified as a particular level or zone. . SIGN UP FOR EMAILGet more great content in your inbox. Methane has a LEL of 4,4 vol%. 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. Zone 0, 1 2 . 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. . 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 This paper will discuss and review the current approaches and solutions of dealing with these HSE concerns, especially with the involvement of hazardous and potentially flammable and explosive chemicals. . 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. This means that the electrical equipment is safe for use within these area by applying special protection strategies. eg Production Area, area surrounding zone 0. This equipment is intended for use in Zone 1 (gases) or Zone 21 (dusts). 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. Zone Hazardous Location 2 Table of . 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. 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. 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. For methane this is shown in the following figure. 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.