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What are 'Dark Factories,' and Do They Really Exist? Equipment marked as suitable for Group IIC is also suitable for IIB and IIA. 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. The inductance of the signal bell coils, combined with breaking of contacts by exposed metal surfaces, resulted in sparks, causing an explosion. A major safety concern in all workplaces is the occurrence of fires and explosions. Refrigerated Container It is essential to know which zone you are working in, so that you can specify the most appropriate equipment. It is always balancing between not defining such areas too large (with highly costs for prevention of ignition sources) or too small (unsafe situations). Dn 2 - a Ce d e r . Zone 1 is an area in which an explosive atmosphere is likely to occur occasionally in normal operation. *unless risk assessment states a higher or lower category is required. 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. Hazards in this group gas can be ignited very easily indeed. Informational Note No. 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. Hazardous area equipment is categorized into category-1 for Zone 0 or Zone 20, category-2 for Zone 1 or Zone 21, and category-3 for Zone 2 or Zone 22. Within the European Union, these are defined by IEC/EN standards (IEC/EN 60079-10-1 or 2) as directed by ATEX. Zone 0 (hazardous area) An area in which an explosive gas-air mixture is continuously present or present for long periods. RP 505 is referred to as the zone system. The key difference between Divisions and Zones relate to terminations. Raytec do not currently offer any lighting solutions for Zone 0. Division defines the probability of the hazardous material being present in an ignitable concentration in the surrounding atmosphere. This has been replaced by a European numerical system, as set out in directive 1999/92/EU implemented in the UK as the Dangerous Substances and Explosives Atmospheres Regulations 2002. Some other standards have more quantitative methods which require more knowledge of the plant, an example is the IEC standard 60079-10-1. . For example, in the US by the Occupational Safety and Health Administration. >> For Gas/Vapor this would be Zone 2. These hazardous (classified) locations are assigned the following designations: For definitions of these locations, see 1910.399. Magnesium, Aluminum, Titanium etc. This article covers the requirements for the, Informational Note No. 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. In the United States, the hazardous location classification system is defined by the National Fire Protection Association (NFPA) 70, National Electric Code(NEC). Then, the level of risk of an explosion is based on the frequency and duration of the occurrence of an explosive atmosphere. The Zone Classification System is offered as an alternative to the Class and Division system. 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. Other ignition sources can also be present, like static electricity. Lets take a look at what defines each zone. No representation is made that the information or references are complete or remain current. For equipment provided with threaded entries for NPT threaded conduit or fittings, listed conduit, conduit fittings, or cable fittings shall be used. Group define the type of hazardous material and (partly) the location of the surrounding atmosphere. WATER TIGHTNESS Zone 0 is an area in which an explosive atmosphere is present continuously for long periods of time or will frequently occur. Areas with possible fire or explosion risks due to explosive atmospheres and/or mixtures - are called hazardous (or classified) locations or areas. It may exist because of repair, maintenance operations, or leakage. You will find this equipment in paint factories, a warehouse or around a bag dump station. An oversimplification of this example is shown in Table 1. Ignitable concentrations of flammable gases or vapors which are present continuously or for long periods of time. The most standards and codes of practise for Hazardous Area Classification describe typical installations and work environments and their hazardous areas. These areas only become hazardous in case of an accident or some unusual operating condition. Youre phone isnt rated for use in hazardous areas. >> NEC: Class II, Division 1, Group F. | IEC: Zone 20, Group IIC. October 2020 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. All areas in the facility that are not Zone 0, Zone 1, or Zone 2 are considered unclassified. SIGN UP FOR EMAILGet more great content in your inbox. Ways to ensure this level of safety are non-arcing design and limitation of the temperature of the equipment. A special standard for instrumentation is IEC/EN 60079-27, describing requirements for Fieldbus Intrinsically Safe Concept (FISCO) (zone 0, 1 or 2) (This special standard has been withdrawn, and has been partially replaced by: IEC/EN60079-11:2011 and IEC/EN60079-25:2010)[1], A special standard for instrumentation is IEC/EN 60079-27, describing requirements for Fieldbus Non-Incendive Concept (FNICO) (zone 2) (This special standard has been withdrawn, and has been partially replaced by: IEC/EN60079-11:2011 and IEC/EN60079-25:2010)[9]. Only emails and answers are saved in our archive. Zone 2. Zone 0 is an area in which an explosive atmosphere is present continuously for long periods of time or will frequently occur. 2: This classification includes, Informational Note No. 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. The Zone system has wider use in the chemical and petrochemical industries. 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. Analysers, motors, control boxes, computers, Any arcs or sparks in this equipment has insufficient energy (heat) to ignite a vapour. Standards and regulations exist to identify such locations, classify the hazards, and design equipment for safe use in such locations. For specific industries, the specific codes for that industry are important to use. May 2019 In other cases, the atmosphere is normally non-hazardous, but a dangerous concentration can be reasonably foreseensuch as operator error or equipment failure. 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. The Class/Division/Group system is based on Article 500 of the National Electrical Code (NEC) where. National Electric Code 2020 edition National Fire Protection Association. No other aspect of safety receives more attention in the form of codes and standards. Two possible classifications are described, in Section 18 (Zones), and Appendix J (Divisions). 1: As a guide in determining when flammable gases or vapors are present continuously or for long periods of time, refer to ANSI/API RP 505-2018, Informational Note No. Which system is preferred depends on the users preference, how the areas are classified, and the wiring system used. Each room, section, or area shall be considered individually in determining its classification. December 2021 Please read AddThis Privacy for more information. 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] August 2020 . Methane has a LEL of 4,4 vol%. Groups E, F, and G are for dusts and flyings (Class II or III). National Electrical Code, NFPA 70, Chapter 5, Article 500, 29 CFR 1910 Subpart S, Electrical 1910.307, NFPA 497, "Classification of Gases, Vapors, and Dusts for Electrical Equipment in Hazardous Classified Locations", NFPA Handbook, "Electrical Installations in Hazardous Locations, " by P. J. Schram and M. W. Earley, NFPA 70E, Chapter 5, "Hazardous (Classified) Locations", ANSI/UL 913, "Intrinsically Safe Apparatus", NFPA 496, "Purged and Pressurized Enclosure for Electrical Equipment in Hazardous Locations. For example the EI 15 and API 500/505 describe specific installations and several conditions for the oil and gas industry. So for an explosion there must be enough fuel. Group defines the type of the hazardous material in the surrounding atmosphere. Iso Container Australia and New Zealand use the same IEC-60079 standards (adopted as AS/NZS60079), however the CE mark is not required. [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. One of the hazards of working with flammable substances is an explosion, mostly hand in hand with fire. June 2022 | For Dust this would be Zone 21. area in which an explosive gas atmosphere is present continuously, or for long periods, or frequently (more than 10% of the time). - 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 . February 2022 . Zone 1 fittings are supplied as silver, Zone 2 as dark grey and industrial fittings as white. Area's are divided into zones. Within a working area or installation an ignition can be created by many factors. NEC has created an Americanized version of the IEC/CENELEC Zone system in a stand-alone article (Article 505). NEW METHODS FOR HAZARDOUS AREA CLASSIFICATION FOR EXPLOSIVE GAS . The surface of a high pressure steam pipe may be above the autoignition temperature of some fuel-air mixtures. This can be achieved by blanketing with nitrogen or carbondioxide. Hazardous area classification. Entire Vapour space of storage tank. 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. 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 . 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. 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. The last condition for an explosion is the presence of an effective ignition source in the direct contact with the fuel/air mixture. Every substance has a differing combination of properties but it is found that they can be ranked into similar ranges, simplifying the selection of equipment for hazardous areas. . 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. Then, the level of risk of an explosion is based on the frequency and duration of the occurrence of an explosive atmosphere. November 2019 Equipment can be designed or modified for safe operation in hazardous locations. Carbon monoxide, ether, hydrogen sulfide, . A hazardous area can be defined as any location where there is risk of an explosion. Area Classification. Informational Note No. When the concentration of gas or vapor is above the UEL the gas mixture is too rich to burn. 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. Equipment that is listed for a Zone 1 location may be installed in a Zone 2 location of the same gas or vapor. The disadvantage of standards with example installations, is that a huge safety factor is incorporated and thus relative large hazardous area are defined. In Europe and the rest of the world - but also more and more in North America - the Zone system is used. |MWD/LWD Cabin A Zone 0 location is a location in which one of the following . . So yes, it is important to choose the right model and always wonder what am I assessing?. In the United States, the NEC uses 2 different classifications: This is an important factor in the classification of hazardous areas. Different countries have approached the standardization and testing of equipment for hazardous areas in different ways. 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. Guidance on assessment of hazards is given in NFPA497 (explosive gas) and NFPA499 (dust). 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. Group is divided in three groups where Group I is reserved for mining locations. 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). THE PRODUCTS YOU NEED, Employers may use the zone classification system as an alternative to the division classification system for electric and electronic equipment and wiring for all voltage in Class I, Zone 0, Zone 1, and Zone 2 hazardous (classified) locations where fire or explosion hazards may exist due to flammable gases, vapors, or liquids. Google use cookies for serving our ads and handling visitor statistics. In ambient conditions it is assured that oxygen is always present and thus not a factor that has to be incorporated within the hazardous area assessment. In Northerm America, instead of the zone classification system, the Class/Division system is used. December 2013, All 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. Equipment shall be marked to show the class, group, and operating temperature or temperature range, based on operation in a 40-degree C ambient, for which it is approved. Powder Filling "q" -- This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. 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. The Zone system has three levels of hazard for gas or dust where the Division system has two. CUTTING SKIPS Drop Test Ex LIGHTER-THAN-AIR GASES & VAPOURS Vapour density of 0.75 is considered as the boundary between lighter and heavier gases / vapours as a safety measure HA of a leak source located in air Source of hazard 4.5 m. 8.0 m R 4.5 m H Class I, Zone 0 or Zone 1 locations may not abut Class I, Division 1 or Division 2 locations. Container Accessories Dust or other small particles suspended in air can explode. Equipment that the employer demonstrates will provide protection from the hazards arising from the flammability of the gas or vapor and the zone of location involved and will be recognized as providing such protection by employees need not be marked. Sources August 2018 Hazardous Environment Classifications: NEC vs IEC, IEC (International Electrotechnical Commission), Group E Metal dusts (eg. 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.