5: For further information on ventilation, see NFPA 30-2018, Informational Note No. The NEMA enclosure rating or IP code may also be indicated, but it is usually independent of the Classified Area suitability. A: Yes. February 2022 Also included in the marking are the manufacturers name or trademark and address, the apparatus type, name and serial number, year of manufacture and any special conditions of use. 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. These areas are classified solely for the purpose of ensuring the safe and proper specification and installation of electrical/electronic equipment. Equipment can be designed or modified for safe operation in hazardous locations. a headlamp, rather than a dedicated fixed luminaire. Equipment approved for use in Class I hazardous locations cannot be used in Class II hazardous locations. Hazardous Area Classification || H2S Zone Classification || Oil and Gas With the advent of electric power, electricity was introduced into coal mines for signaling, illumination, and motors. We don't collect information from our users. Which system is preferred depends on the users preference, how the areas are classified, and the wiring system used. Zone 1 2. The definition of Zone 2 is a hazardous area classified as an atmosphere where a mixture of air and flammable substances in the form of gas, vapour or mist is not likely to occur in normal operation, but if it does occur, will persist for a short period only. Informational Note: For further information regarding classification and ventilation of areas involving closed-circuit ammonia refrigeration systems, see ANSI/IIAR 2-2014. These generally give rise to areas classied as Zones 0, 1, and 2 respectively. This value of this LOC differs per substance and depends also on the inert gas for achieving a low oxygen concentration. 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). 1: Normal operation is considered the situation when plant, Informational Note No. 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 . An area where combustible dusts or ignitable fibers and flyings are present continuously or for long periods of time. December 2022 A more quantitative method is described in IEC 60079-10-1 but also more sophisticated numeric mathematical models can be used like Computational Fluid Dynamics. The types of protection are subdivided into several sub classes, linked to EPL: ma and mb, px, py and pz, ia, ib and ic. April 2021 . Identifying Zone 0, Zone 1, and Zone 2 Hazardous Areas. | For Gas/Vapor this would be Zone 0. Temperature Control What Are All Those Gadgets On A Multitool? February 2019 October 2021 Hazardous Area Classification Questions - Inst Tools Methane has a UEL of 17 vol%, which means when the concentration of methane in air is above the 17 vol% an explosion cannot occur even when an ignition source is present. The plan may contain the list of chemicals with their group and temperature rating. See Figure S-1 for an explanation of this marking. 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). 2: For the requirements for electrical and electronic. If equipment is marked, for example, Ex e II T4 then it is suitable for all subgroups IIA, IIB and IIC. 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. 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. You can target the Engineering ToolBox by using AdWords Managed Placements. 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. Safe for the hazardous (classified) location. 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 example the EI 15 and API 500/505 describe specific installations and several conditions for the oil and gas industry. 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. PDF Zone Hazardous Location - Rockwell Automation D8.1.3 Hazardous areas are subdivided into Zones 0,1 or 2, the definitions of each cate-gory being as follows: Zone 0 an area in which an explosive gas-air mixture is continuously present or present for long periods. As a guide for Zone 0, this can be defined as over 1,000 hours/year or >10% of the time. PDF Hazardous Area Classification - dust atmospheres - IECEx In Europe the ATEX 114 Directive (2014/34/EU) is applicable to equipment that is used in hazardous area's. A: When comparing Divisions and Zones, Division 2 is equivalent to Zone 2, but Division 1 is equivalent to either Zone 0 or 1. August 2018 SEWAGE TREATMENT The autoignition temperature is the lowest temperature at which the substance will ignite without an additional heat or ignition source (at atmospheric pressure). The most standards and codes of practise for Hazardous Area Classification describe typical installations and work environments and their hazardous areas. 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. Where pyrophoric materials are the only materials used or handled, these locations need not be classified. 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. Oxygen is required in high quantities and in combination with the flammable substance to produce an explosive atmosphere. 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 20, 21, and 22 Locations for Combustible Dusts or - UpCodes For more detailed assessments or for situations where no specific industry standards are available , like the chemical or pharmaceutical sector and also specific installation for oil and gas industries, a more quantitative approach can be used. |MWD/LWD Cabin In 29 CFR 1910.307(c)(2)(ii), OSHA requires all equipment used in a hazardous location to be marked with the class, group and operating temperature or temperature range for which it is approved. 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. 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. Category 3 equipment may only be used in zone 2 areas. The upper explosion limit of a substance is the highest concentration (in volume percentages for gases and liquids) of a gas or a vapor in air capable of producing a flash of fire in the presence of an ignition source. Motors, lighting, junction boxes, electronic equipment, This method, being by definition special, has no specific rules. 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. 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. Class I: hazardous because flammable gases or vapors are present in the air in quantities sufficient to produce explosive or ignitable mixtures: . Zone type (0/1/2/ 20/21/ 22) Zone extent. . HAZARDOUS VS. ". The term equipment is applied both for fixed equipment and mobile equipment that are operated in such area. 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. 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 Examples are: production facilities in the food industry, chemical plants, oil & gas, and the pharmaceutical industry etc. Both external and internal temperatures are taken into consideration. See below for further details: Division system sample marking National Electric Code 2020 edition National Fire Protection Association. NFPA 70 NEC Zone Classification System The Zone Classification System is offered as an alternative to the Class and Division system. 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. Q: Are Divisions and Zones equivalent to one another? The design of the equipment must ensure protection, even in the event of rare incidents relating to the equipment. A potential few examples of this are: The air space inside a tank of petrol Click on the zone to learn more about the classification according to IEC 60079-10 standards. Electrical equipment installed in such locations can provide an ignition source, due to electrical arcing, or high temperatures. July 2022 In North America the suitability of equipment for the specific hazardous area must be tested by a Nationally Recognized Testing Laboratory, such as UL, FM Global, CSA Group, or Intertek (ETL). 0. 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. International Electrotechnical Committee (IEC) Hazardous Area Classification. It uses the familiar Class/Division system and adapts the IEC/CENELEC Zones into it while maintaining NEC wiring methods and . In Europe the label must show the CE mark and the code number of the certifying/notified body). The lower explosion limit of a substance is the lowest concentration (in volume percentages for gases and liquids) of a gas or a vapor in air of producing a flash of fire in the presence of an ignition source.

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