Electrical equipment in hazardous areas

31: 222:

explosive dust. Equipment is placed into protection level categories according to manufacture method and suitability for different situations. Unlike ATEX which uses numbers to define the safety "Category" of equipment (namely 1, 2, and 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. <IEC 60079.14>

206: 369:. The only explosive or flammable liquids are paint and brush cleaner. These are designated as very low risk of causing an explosion and are more of a fire risk (although gas explosions in residential buildings do occur). Unclassified locations in chemical and other plants are present where it is absolutely certain that the hazardous gas is diluted to a concentration below 25% of its lower 1503: 533:(MESG), minimum igniting current (MIC) ratio, explosion pressure and time to peak pressure, spontaneous ignition temperature, and maximum rate of pressure rise. 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. 186:(NEC), defines area classification and installation principles. NEC article 500 describes the NEC Division classification system, while articles 505 and 506 describe the NEC Zone classification system. The NEC Zone system was created to harmonize with IEC classification system, and therefore reduce the complexity of management. 537:

autoignition temperature yet if its flash-point is above the ambient temperature, then the area may not need to be classified. Conversely if the same material is heated and handled above its flash-point, the area must be classified for proper electrical system design, as it will then form an ignitable mixture.

383: 754:

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. The above groups are formed in order of how explosive the material would be if it was ignited, with IIC being the most explosive zone system gas group

1245:

Many items of EEx rated equipment will employ more than one method of protection in different components of the apparatus. These would be then labeled with each of the individual methods. For example, a socket outlet labeled EEx'de' might have a case made to EEx 'e' and switches that are made to EEx

355:

An area where ignitable concentrations of flammable gases, vapors or liquids are not likely to exist under normal operating conditions. In this area the gas, vapor or liquids would only be present under abnormal conditions (most often leaks under abnormal conditions). As a general guide for Zone 2,

337:

An area where ignitable concentrations of flammable gases, vapors or liquids are present continuously or for long periods of time under normal operating conditions. An example of this would be the vapor space above the liquid in the top of a tank or drum. The ANSI/NEC classification method consider

998:

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 escaping (hot) gases must sufficiently cool down along the escape path that by the time

536:

Flammability of combustible liquids are defined by their flash-point. The flash-point is the temperature at which the material will generate sufficient quantity of vapor to form an ignitable mixture. The flash point determines if an area needs to be classified. A material may have a relatively low

1225:

This method, being by definition special, has no specific rules. In effect it is any method which can be shown to have the required degree of safety in use. Much early equipment having Ex s protection was designed with encapsulation and this has now been incorporated into IEC 60079-18 . Ex s is a

750:

Group IIC is the most severe zone system gas group. Hazards in this group gas can be ignited very easily indeed. Equipment marked as suitable for Group IIC is also suitable for IIB and IIA. Equipment marked as suitable for IIB is also suitable for IIA but NOT for IIC. If equipment is marked, for

364:

Also known as non-hazardous or ordinary locations, these locations are determined to be neither Class I, Division 1 or Division 2; Zone 0, Zone 1 or Zone 2; or any combination thereof. Such areas include a residence or office where the only risk of a release of explosive or flammable gas would be

221:

publishes the 60079 series of standards 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". IEC 60079-10-1 covers classification of explosive gas atmospheres, and IEC 60079-10-2

90:

A light switch may cause a small, harmless spark when switched on or off. In an ordinary household this is of no concern, but if a flammable atmosphere is present, the arc might start an explosion. In many industrial, commercial, and scientific settings, the presence of such an atmosphere is a

1560:

Industrial electrical equipment for hazardous area has to conform to appropriate parts of standard: IEC-60079 for gas hazards, and IEC-61241 for dust hazards. In some cases, it must be certified as meeting that standard. Independent test houses—Notified Bodies—are established in most European

126:

Different countries have approached the standardization and testing of equipment for hazardous areas in different ways. Terminology for both hazards and protective measures can vary. Documentation requirements likewise vary. As world trade becomes more globalized, international standards are

1661:

At least two British mine explosions were attributed to an electric bell signal system. 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. The

1617:

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. Some equipment in

767:

of the hazardous atmosphere. Both external and internal temperatures are taken into consideration. The autoignition temperature is the lowest temperature at which the substance will ignite without an additional heat or ignition source (at atmospheric pressure). This temperature is used for

249:, and similar facilities likewise present the risk of a clouds of dust. In some cases, the hazardous atmosphere is present all the time, or for long periods. In other cases, the atmosphere is normally non-hazardous, but a dangerous concentration can be reasonably foreseen—such as 1122:

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. The overpressure is monitored, maintained and controlled.

889:

The above table shows that the surface temperature of a piece of electrical equipment with a temperature classification of T3 will not rise above 200 °C. The surface of a high pressure steam pipe may be above the autoignition temperature of some fuel-air mixtures.

1241:

The types of protection are subdivided into several sub classes, linked to EPL: ma and mb, px, py and pz, ia, ib and ic. The a subdivisions have the most stringent safety requirements, taking into account more than one independent component faults simultaneously.

1226:

coding referenced in IEC 60079-0. The use of EPL and ATEX Category directly is an alternative for "s" marking. The IEC standard EN 60079-33 is made public and is expected to become effective soon, so that the normal Ex certification will also be possible for Ex-s

276:

is provided to identify equipment ratings and installation techniques to be used for each classified area. The plan may contain the list of chemicals with their group and temperature rating. The classification process requires the participation of

102:

Several protection strategies exist. 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

1518:). The CE mark is complemented with the Ex mark: A yellow-filled hexagon with the Greek letters εχ (epsilon chi), followed by the Group, Category, and, if Group II, G or D (gas or dust). Specific types of protection being used will also be marked. 913:, also called non-incendive, limits the energy present in a system, such that it is insufficient to ignite a hazardous atmosphere under any conditions. This includes both low power levels, and low stored energy. Common with instrumentation. 472:

An old British standard used letters to designate zones. 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.

122:

designs equipment to operate using minimal energy, insufficient to cause ignition. Explosion-proofing designs equipment to contain ignition hazards, prevent entry of hazardous substances, and, contain any fire or explosion that could occur.

328:

An area where ignitable concentrations of flammable gases, vapors or liquids can exist all of the time or some of the time under normal operating conditions. A Class I, Division 1 area encompasses the combination of Zone 0 and Zone 1

346:

An area where ignitable concentrations of flammable gases, vapors or liquids are likely to exist under normal operating conditions. As a guide for Zone 1, this can be defined as 10–1000 hours per year or 0.1–10% of the

755:

and IIA being the least. 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.

1621:

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. The NEMA enclosure rating or

952:

Controls can be fitted to detect dangerous concentrations of hazardous gas, or failure of countermeasures. Upon detection, appropriate action is automatically taken, such as removing power, or providing

1610:

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 (

1849: 1164:

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)

138:. Classification of locations, testing and listing of equipment, and inspection of installation, is typically overseen by governmental bodies. For example, in the US by the 1607:

The label will always list the class, division and may list the group and temperature code. Directly adjacent on the label one will find the mark of the listing agency.

1254:

In recent years also the EPL is specified for several kinds of protection. The required protection level is linked to the intended use in the zones described below:

1202:

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)

197:, which defines area classification and installation principles. Two possible classifications are described, in Section 18 (Zones), and Appendix J (Divisions). 921:

Explosion-proof or flame-proof equipment is sealed and rugged, such that it will not ignite a hazardous atmosphere, despite any sparks or explosion within.

159:(NFPA) publishes several relevant standards, and they are often adopted by government agencies. Guidance on assessment of hazards is given in NFPA 338:

this environment a Class I, Division 1 area. As a guide for Zone 0, this can be defined as over 1000 hours per year or more than 10% of the time.

253:

or equipment failure. Locations are thus classified by type and risk of release of gas, vapor, or dust. Various regulations use terms such as

1926: 1877: 1752: 1431: 139: 1857: 1618:

Division 2 areas do not require a specific label, such as standard 3 phase induction motors that do not contain normally arcing components.

517:

Different explosive atmospheres have chemical properties that affect the likelihood and severity of an explosion. Such properties include

209:

A telephone for use in mines, constructed so as not to cause external explosion of hazardous atmospheres. The heavy case is secured with

1585: 1566: 218: 225:

The IEC 60079 standard set has been adapted for use in Australia and New Zealand and is published as the AS/NZS 60079 standard set.

1666:

of the signal bell coils, combined with breaking of contacts by exposed metal surfaces, resulted in sparks, causing an explosion.

34:

This inspection lamp is constructed so that it cannot set off an explosion when surrounded by specified flammable gases or dust.

1965: 2060: 1480: 82:

and regulations exist to identify such locations, classify the hazards, and design equipment for safe use in such locations.

156: 999:

they reach the outside of the enclosure not to be a source of ignition of the outside, potentially ignitable surroundings.

301:, and other pertinent documents. Area classification documentations are reviewed and updated to reflect process changes. 1903: 1706: 1494:

All equipment certified for use in hazardous areas must be labelled to show the type and level of protection applied.

2046: 2032: 1832: 1562: 903:

Equipment can be designed or modified for safe operation in hazardous locations. The two general approaches are:

91:

common, or at least commonly possible, occurrence. Protecting against fire and explosion is of interest for both

67: 17: 1934:(2020 ed.), National Fire Protection Association, chapter 1, article 100, part III, page 70-43, 2019-08-05 1463:

Certified and labeled for use in locations rated NEC Class I, Groups A, B, C, and D; both indoors and outdoors

92: 2080: 1611: 530: 168: 2085: 2075: 1561:

countries, and a certificate from any of these will be accepted across the EU. In the United Kingdom,

241:, handling of large quantities of flammable liquids and gases creates a risk of exposure. Coal mines, 108: 1990: 128: 30: 1883: 1589: 764: 194: 183: 1825:

Hazardous Locations: A Guide for the Design, Construction and Installation of Electrical Equipment

1584:

In North America the suitability of equipment for the specific hazardous area must be tested by a

771:

The temperature classification on the electrical equipment label will be one of the following (in

131:, so that a wider range of acceptable techniques can be approved by national regulatory agencies. 498:

ignitable concentrations of dust, fibers, or flyings are likely to exist under normal conditions

282: 96: 929:

The equipment housing may be sealed to prevent entry of flammable gas or dust into the interior.

445:

ignitable fibers, or materials producing combustible flyings, are handled, manufactured or used

506:

ignitable concentrations of dust, fibers, or flyings unlikely to exist under normal conditions

39: 935:

Enclosures can be pressurized with clean air or inert gas, displacing any hazardous substance.

932:

The housing may be strong enough to contain and cool any combustion gases produced internally.

1802: 1635: 278: 1455:

Certified and labeled for use in indoor locations rated NEC Class I, Groups A, B, C, and D

1435: 1425: 71: 490:

ignitable concentrations of dust, fibers, or flyings are present for long periods of time

8: 1626:

may also be indicated, but it is usually independent of the Classified Area suitability.

356:

unwanted substances should only be present under 10 hours per year or 0–0.1% of the time.

104: 1438:

for a variety of applications. Some of these are specifically for hazardous locations:

1691: 1198:

A special standard for instrumentation is IEC/EN 60079–27, describing requirements for

1160:

A special standard for instrumentation is IEC/EN 60079–27, describing requirements for

1155: 370: 79: 43: 1654:. This was accompanied by electrically initiated explosions of flammable gas such as 1145:

Any arcs or sparks in this equipment has insufficient energy (heat) to ignite a vapour

2056: 2042: 2028: 1828: 945:

Heat-producing elements can be designed to limit their maximum temperature below the

518: 298: 925:

Several techniques of flame-proofing exist, and they are often used in combination:

1701: 1554:

Type n, non-sparking, Group 2 gases, Temperature class 3, special conditions apply

1405:

The equipment category indicates the level of protection offered by the equipment.

1137: 1102:

Equipment components of the equipment are usually encased in a resin type material

1082:

Equipment components are completely covered with a layer of sand, powder or quartz

910: 526: 522: 119: 1716: 1471:

Certified and labeled for use in locations rated NEC Class II, Groups E, F, or G

290: 115: 938:

Arc-producing elements can be isolated from the atmosphere, by encapsulation in

426:

ignitable concentrations of combustible dust can exist, under normal conditions

1680: 1651: 1647: 772: 395: 387: 250: 246: 238: 210: 75: 63: 134:

The process of determining the type and size of hazardous locations is called

2069: 1711: 1696: 1572:

Australia and New Zealand use the same IEC-60079 standards (adopted as AS/NZS

1515: 1151: 540:

Each chemical gas or vapour used in industry is classified into a gas group.

366: 114:

When equipment must be placed in a hazardous location, it can be designed to

1951: 1773: 1729: 1165: 434:

ignitable concentrations of combustible dust are unlikely to exist normally

946: 751:

example, Ex e II T4 then it is suitable for all subgroups IIA, IIB and IIC

461:

Non-hazardous or ordinary locations. Determined to be none of the above.

1639: 310: 286: 763:

Equipment should be tested to ensure that it does not exceed 80% of the

27:

Electrical equipment in places where fire or explosion hazards may exist

1663: 1069: 382: 242: 1266: 1675: 1655: 1643: 1597: 1593: 1011: 273: 190: 51: 1856:, International Association of Electrical Inspectors, archived from 205: 2055:, The Engineering Equipment and Materials Users Association, 2017, 1601: 1409:

Category 1 equipment may be used in zone 0, zone 1 or zone 2 areas.

1199: 1161: 1015: 1007: 730:

Ignitible fibers or flyings, such as cotton lint, flax & rayon

314: 294: 234: 74:

installed in such locations can provide an ignition source, due to

1039:

Equipment is very robust and components are made to a high quality

1850:"Hazardous (Classified) Locations — NEC Articles 500 through 517" 1623: 1511: 1003: 529:. Empirical testing is done to determine parameters such as the 318: 630:

Ignitible fibers/flyings, such as cotton lint, flax & rayon

2053:

A Practitioner's Handbook for potentially explosive atmospheres

1803:"Hazardous Area Classification and Control of Ignition Sources" 1685: 719:

Non-conductive dusts, such as flour, grain, wood & plastic

619:

Non-conductive dusts, such as flour, grain, wood & plastic

1973:, National Electrical Manufacturers Association, November 2005 1775:

IEC 60079:2020 SER Series - Explosive atmospheres - ALL PARTS

1614:) to permit operation of the electrical installation/system. 939: 59: 200: 1506:

Mark for ATEX certified equipment for explosive atmospheres

1412:

Category 2 equipment may be used in zone 1 or zone 2 areas.

1148:

Equipment can be installed in ANY housing provided to IP54.

1502: 768:

classification for industry and technology applications.

293:

professionals; and the use of process diagrams, material

55: 1002:

Equipment has flameproof gaps (max 0.006" (150 μm)

1778:, International Electrotechnical Commission, 2020-06-26 1214:

Motors, lighting, junction boxes, electronic equipment

1827:. Toronto: Canadian Standards Association. Chapter 9. 1415:

Category 3 equipment may only be used in zone 2 areas.

1060:

Equipment components are completely submerged in oil

321:

are also common industrial gases that are flammable.

46:

engineering, hazardous locations (HazLoc, pronounced

54:

hazards may exist. Sources of such hazards include

1805:. UK Health and Safety Executive. 22 September 2004 1249: 394:Dust or other small particles suspended in air can 1925: 611:Carbonaceous dusts, such as carbon & charcoal 352:Class I, Division 2 or Zone 2 classified locations 1232:Zone depending upon manufacturer's certification 603:Metal dusts, such as magnesium (Division 1 only) 2067: 639:NEC & IEC Zone System gas & dust groups 213:bolts to deter unauthorized opening of the case. 2039:Electrical Installations in Hazardous Locations 1317:explosive atmosphere between 10 and 1000 hrs/yr 1538:Explosion protected, Group 2, Category 1, Gas 1158:unit may be used to assist with certification. 1028:Motors, lighting, junction boxes, electronics 1025:Zone 1 if gas group & temp. class correct 453:easily ignitable fibers are stored or handled 1847: 1576:60079), however the CE mark is not required. 1546:Type ia, Group 2C gases, Temperature class 4 1432:National Electrical Manufacturers Association 721:(equivalent to NEC Class II, Groups F and G) 140:Occupational Safety and Health Administration 1822: 1797: 1795: 1793: 1791: 1368:explosive surface between 10 and 1000 hrs/yr 1334:explosive atmosphere between 1 and 10 hrs/yr 1132:Analysers, motors, control boxes, computers 898: 663:(equivalent to NEC Class I, Groups A and B) 2025:Electrical Installations in Hazardous Areas 1195:Equipment is non-incendive or non-sparking. 521:, minimum ignition energy, upper and lower 546:NEC Division System gas & dust groups 1788: 1385:explosive surface between 1 and 10 hrs/yr 219:International Electrotechnical Commission 201:International Electrotechnical Commission 1816: 1586:Nationally Recognized Testing Laboratory 1501: 457: 381: 325:Class I, Division 1 classified locations 204: 29: 1952:"IEC 60079-27:2008 | IEC Webstore" 1823:Bossert, John; Hurst, Randolph (1986). 1419: 1275: 14: 2068: 1755:. National Fire Protection Association 1184:Instrumentation, measurement, control 962: 710:(equivalent to NEC Class II, Group E) 512: 269:to differentiate the various hazards. 1569:are the most well known such bodies. 1481:Mine Safety and Health Administration 1400: 1300:explosive atmosphere > 1000 hrs/yr 949:temperature of the material involved. 696:(equivalent to NEC Class I, Group D) 685:(equivalent to NEC Class I, Group C) 674:(equivalent to NEC Class I, Group B) 390:in Kansas killed five workers in 1998 708:Conductive dusts, such as magnesium 365:such things as the propellant in an 157:National Fire Protection Association 1707:Mineral-insulated copper-clad cable 1658:(methane) and suspended coal dust. 171:publishes analogous standards in RP 24: 2017: 1879:Autoignition temperature of liquid 1638:, electricity was introduced into 1579: 1510:In Europe the label must show the 1351:explosive surface > 1000 hrs/yr 1129:Zone 1 (px or py), or zone 2 (pz) 233:In an industrial plant, such as a 25: 2097: 1905:Explosion Proof & Flame Proof 1753:"NFPA 70, National Electric Code" 1108:Zone 1 (Ex mb) or Zone 0 (Ex ma) 1049:Motors, lighting, junction boxes 467: 377: 373:(or lower explosive limit (LEL)). 189:Canada has a similar system with 66:, fibers, and flyings, which are 1250:Equipment protection level (EPL) 1091:Electronics, telephones, chokes 304: 150: 2005: 1983: 1958: 1076:Sand, powder, or quartz Filled 942:, immersion in oil, or similar. 624:Class III, Divisions 1 & 2 1944: 1918: 1896: 1882:, OZM Research, archived from 1870: 1841: 1766: 1745: 1483:(MSHA), 30 CFR Part 18 (1978) 1479:Meets the requirements of the 1326:ib, mb, px, py, d, e, o, q, s 758: 738:Mines susceptible to firedamp 597:Class II, Divisions 1 & 2 13: 1: 2027:, Butterworth-Heineman 1998, 1722: 1612:Authority Having Jurisdiction 1434:(NEMA) defines standards for 732:(equivalent to NEC Class III 562:Class I, Divisions 1 & 2 531:maximum experimental safe gap 386:An explosion of dust at this 309:Typical gas hazards are from 272:Often an area classification 2041:, Jones and Bartlett, 1997, 1848:Keith Lofland (2014-11-10), 1384: 1367: 1350: 1333: 1316: 1299: 1284: 1235:As its certification states 957: 893: 860: 846: 832: 818: 804: 169:American Petroleum Institute 163:497 (explosive gas) and NFPA 145: 7: 1730:"Hazardous Location Motors" 1669: 1514:and the code number of the 1489: 334:Zone 0 classified locations 155:In the US, the independent 85: 50:) are places where fire or 10: 2102: 1992:NEMA/IEC Enclosure Ratings 1927:"Explosionproof Equipment" 1629: 1423: 343:Zone 1 classified location 228: 1995:, Cole-Parmer, 2018-10-15 1497: 1259: 899:General types and methods 780: 701: 661:Acetylene & hydrogen 654: 650:Representative materials 638: 596: 561: 557:Representative materials 545: 438: 419: 78:, or high temperatures. 1932:National Electrical Code 1516:certifying/notified body 791:Continuous - Short time 765:autoignition temperature 195:Canadian Electrical Code 184:National Electrical Code 68:combustible or flammable 1010:, 0.004" (100 μm) 118:of fire or explosion. 1507: 1111:Electronics (no heat) 401: 391: 361:Unclassified locations 214: 35: 1505: 702:Zone 20, 21 & 22 385: 208: 33: 2081:Explosion protection 1967:NEMA Enclosure Types 1426:NEMA enclosure types 1420:NEMA enclosure types 600:E (Division 1 only) 193:standard C22.1, the 72:Electrical equipment 1688:competency standard 1634:With the advent of 1523: 1219:Special protection 1177:'ia': Zone 0 & 1150:A 'Zener Barrier', 1116:Pressurised/purged 963:Types of protection 513:Gas and dust groups 2086:Natural gas safety 2011:Bossert 86 page 17 1692:Electrical conduit 1521: 1508: 1401:Equipment category 1276:type of protection 1138:Intrinsically safe 655:Zone 0, 1 & 2 392: 371:flammability limit 299:safety data sheets 215: 36: 2076:Electrical safety 2061:978-0-85931-222-6 1558: 1557: 1522:Example markings 1487: 1486: 1398: 1397: 1239: 1238: 1088:Zone 2 or Zone 1 1066:Zone 2 or Zone 1 1046:Zone 2 or Zone 1 1033:Increased safety 887: 886: 748: 747: 634: 633: 592:Propane, methane 519:flame temperature 510: 509: 465: 464: 167:499 (dust). The 111:with clean air). 76:electrical arcing 16:(Redirected from 2093: 2012: 2009: 2003: 2002: 2001: 2000: 1987: 1981: 1980: 1979: 1978: 1972: 1962: 1956: 1955: 1948: 1942: 1941: 1940: 1939: 1929: 1922: 1916: 1915: 1914: 1913: 1908:, Intertek Group 1900: 1894: 1893: 1892: 1891: 1874: 1868: 1867: 1866: 1865: 1845: 1839: 1838: 1820: 1814: 1813: 1811: 1810: 1799: 1786: 1785: 1784: 1783: 1770: 1764: 1763: 1761: 1760: 1749: 1740: 1738: 1737: 1732:. Dietz Electric 1702:Intrinsic safety 1575: 1524: 1520: 1441: 1440: 1257: 1256: 1229:IEC/EN 60079-33 1208:IEC/EN 60079-27 1170:IEC/EN 60079-25 1105:IEC/EN 60079-18 967: 966: 911:Intrinsic safety 907:Intrinsic safety 778: 777: 636: 635: 543: 542: 527:molecular weight 523:explosive limits 476: 475: 406: 405: 211:tamper-resistant 178: 174: 166: 162: 120:Intrinsic safety 93:personnel safety 21: 2101: 2100: 2096: 2095: 2094: 2092: 2091: 2090: 2066: 2065: 2023:Alan McMillan, 2020: 2018:Further reading 2015: 2010: 2006: 1998: 1996: 1989: 1988: 1984: 1976: 1974: 1970: 1964: 1963: 1959: 1950: 1949: 1945: 1937: 1935: 1924: 1923: 1919: 1911: 1909: 1902: 1901: 1897: 1889: 1887: 1876: 1875: 1871: 1863: 1861: 1846: 1842: 1835: 1821: 1817: 1808: 1806: 1801: 1800: 1789: 1781: 1779: 1772: 1771: 1767: 1758: 1756: 1751: 1750: 1746: 1735: 1733: 1728: 1725: 1717:Pressure piling 1672: 1632: 1582: 1573: 1500: 1492: 1436:enclosure types 1430:In the US, the 1428: 1422: 1403: 1252: 1207: 1206:IEC/EN 60079-15 1196: 1180: 1178: 1174:IEC/EN60079-27 1173: 1172:IEC/EN 60079-11 1171: 1159: 1149: 1146: 1126:IEC/EN 60079-2 1085:IEC/EN 60079-5 1063:IEC/EN 60079-6 1043:IEC/EN 60079-7 1040: 1022:IEC/EN 60079-1 1000: 965: 960: 918:Explosion proof 901: 896: 790: 785: 761: 515: 470: 404: 380: 313:compounds, but 307: 291:instrumentation 231: 203: 176: 172: 164: 160: 153: 148: 116:reduce the risk 105:process changes 88: 28: 23: 22: 18:Explosion proof 15: 12: 11: 5: 2099: 2089: 2088: 2083: 2078: 2064: 2063: 2049: 2035: 2019: 2016: 2014: 2013: 2004: 1982: 1957: 1943: 1917: 1895: 1869: 1840: 1833: 1815: 1787: 1765: 1743: 1742: 1741: 1724: 1721: 1720: 1719: 1714: 1709: 1704: 1699: 1694: 1689: 1683: 1681:ATEX directive 1678: 1671: 1668: 1636:electric power 1631: 1628: 1581: 1578: 1556: 1555: 1552: 1551:Ex nA II T3 X 1548: 1547: 1544: 1540: 1539: 1536: 1532: 1531: 1528: 1499: 1496: 1491: 1488: 1485: 1484: 1477: 1473: 1472: 1469: 1465: 1464: 1461: 1457: 1456: 1453: 1449: 1448: 1445: 1424:Main article: 1421: 1418: 1417: 1416: 1413: 1410: 1402: 1399: 1396: 1395: 1392: 1389: 1386: 1383: 1379: 1378: 1375: 1372: 1369: 1366: 1362: 1361: 1358: 1355: 1352: 1349: 1345: 1344: 1341: 1338: 1335: 1332: 1328: 1327: 1324: 1321: 1318: 1315: 1311: 1310: 1307: 1304: 1301: 1298: 1294: 1293: 1291: 1288: 1286: 1283: 1279: 1278: 1272: 1269: 1264: 1261: 1251: 1248: 1237: 1236: 1233: 1230: 1227: 1223: 1220: 1216: 1215: 1212: 1209: 1204: 1193: 1190: 1189:Non-incendive 1186: 1185: 1182: 1175: 1168: 1143: 1140: 1134: 1133: 1130: 1127: 1124: 1120: 1117: 1113: 1112: 1109: 1106: 1103: 1100: 1097: 1093: 1092: 1089: 1086: 1083: 1080: 1077: 1073: 1072: 1067: 1064: 1061: 1058: 1055: 1051: 1050: 1047: 1044: 1041: 1037: 1034: 1030: 1029: 1026: 1023: 1020: 996: 993: 989: 988: 985: 982: 979: 976: 973: 964: 961: 959: 956: 955: 954: 950: 943: 936: 933: 930: 923: 922: 919: 915: 914: 908: 900: 897: 895: 892: 885: 884: 881: 878: 874: 873: 870: 867: 863: 862: 861:G5: 80 - 90 859: 856: 853: 849: 848: 847:G4: 110 - 125 845: 842: 839: 835: 834: 833:G3: 160 - 180 831: 828: 825: 821: 820: 819:G2: 240 - 270 817: 814: 811: 807: 806: 805:G1: 360 - 400 803: 800: 797: 793: 792: 787: 782: 773:degree Celsius 760: 757: 746: 745: 742: 739: 735: 734: 728: 724: 723: 717: 713: 712: 706: 703: 699: 698: 692: 688: 687: 681: 677: 676: 670: 666: 665: 659: 656: 652: 651: 648: 645: 641: 640: 632: 631: 628: 625: 621: 620: 617: 613: 612: 609: 605: 604: 601: 598: 594: 593: 590: 586: 585: 582: 578: 577: 574: 570: 569: 566: 563: 559: 558: 555: 552: 548: 547: 514: 511: 508: 507: 504: 500: 499: 496: 492: 491: 488: 484: 483: 480: 469: 468:United Kingdom 466: 463: 462: 459: 455: 454: 451: 447: 446: 443: 440: 436: 435: 432: 428: 427: 424: 421: 417: 416: 413: 410: 403: 400: 388:grain elevator 379: 378:Explosive dust 376: 375: 374: 362: 358: 357: 353: 349: 348: 344: 340: 339: 335: 331: 330: 326: 306: 303: 251:operator error 239:chemical plant 230: 227: 202: 199: 152: 149: 147: 144: 136:classification 87: 84: 26: 9: 6: 4: 3: 2: 2098: 2087: 2084: 2082: 2079: 2077: 2074: 2073: 2071: 2062: 2058: 2054: 2050: 2048: 2047:0-87765-423-9 2044: 2040: 2037:Peter Schram 2036: 2034: 2033:0-7506-3768-4 2030: 2026: 2022: 2021: 2008: 1994: 1993: 1986: 1969: 1968: 1961: 1953: 1947: 1933: 1928: 1921: 1907: 1906: 1899: 1886:on 2016-06-18 1885: 1881: 1880: 1873: 1860:on 2017-07-05 1859: 1855: 1854:IAEI Magazine 1851: 1844: 1836: 1834:0-9690124-5-4 1830: 1826: 1819: 1804: 1798: 1796: 1794: 1792: 1777: 1776: 1769: 1754: 1748: 1744: 1731: 1727: 1726: 1718: 1715: 1713: 1712:Notified Body 1710: 1708: 1705: 1703: 1700: 1698: 1697:Grounding kit 1695: 1693: 1690: 1687: 1684: 1682: 1679: 1677: 1674: 1673: 1667: 1665: 1659: 1657: 1653: 1649: 1645: 1641: 1637: 1627: 1625: 1619: 1615: 1613: 1608: 1605: 1603: 1599: 1595: 1591: 1587: 1580:North America 1577: 1570: 1568: 1564: 1553: 1550: 1549: 1545: 1543:Ex ia IIC T4 1542: 1541: 1537: 1534: 1533: 1529: 1526: 1525: 1519: 1517: 1513: 1504: 1495: 1482: 1478: 1475: 1474: 1470: 1467: 1466: 1462: 1459: 1458: 1454: 1451: 1450: 1446: 1443: 1442: 1439: 1437: 1433: 1427: 1414: 1411: 1408: 1407: 1406: 1393: 1390: 1387: 1381: 1380: 1376: 1373: 1370: 1364: 1363: 1359: 1356: 1353: 1347: 1346: 1342: 1339: 1336: 1330: 1329: 1325: 1322: 1319: 1313: 1312: 1308: 1305: 1302: 1296: 1295: 1292: 1289: 1287: 1281: 1280: 1277: 1273: 1270: 1268: 1265: 1262: 1258: 1255: 1247: 1243: 1234: 1231: 1228: 1224: 1221: 1218: 1217: 1213: 1210: 1205: 1203: 1201: 1194: 1191: 1188: 1187: 1183: 1176: 1169: 1167: 1166: 1163: 1157: 1153: 1152:opto-isolator 1144: 1141: 1139: 1136: 1135: 1131: 1128: 1125: 1121: 1118: 1115: 1114: 1110: 1107: 1104: 1101: 1098: 1096:Encapsulated 1095: 1094: 1090: 1087: 1084: 1081: 1078: 1075: 1074: 1071: 1068: 1065: 1062: 1059: 1056: 1053: 1052: 1048: 1045: 1042: 1038: 1035: 1032: 1031: 1027: 1024: 1021: 1019: 1017: 1013: 1009: 1005: 997: 994: 991: 990: 986: 983: 980: 977: 974: 972: 969: 968: 953:notification. 951: 948: 944: 941: 937: 934: 931: 928: 927: 926: 920: 917: 916: 912: 909: 906: 905: 904: 891: 882: 879: 876: 875: 871: 868: 865: 864: 857: 854: 851: 850: 843: 840: 837: 836: 829: 826: 823: 822: 815: 812: 809: 808: 801: 798: 795: 794: 788: 784:International 783: 779: 776: 774: 769: 766: 756: 752: 743: 741:I (IEC only) 740: 737: 736: 733: 729: 726: 725: 722: 718: 715: 714: 711: 707: 704: 700: 697: 693: 690: 689: 686: 682: 679: 678: 675: 671: 668: 667: 664: 660: 657: 653: 649: 646: 643: 642: 637: 629: 626: 623: 622: 618: 615: 614: 610: 607: 606: 602: 599: 595: 591: 588: 587: 583: 580: 579: 575: 572: 571: 567: 564: 560: 556: 553: 550: 549: 544: 541: 538: 534: 532: 528: 524: 520: 505: 502: 501: 497: 494: 493: 489: 486: 485: 481: 478: 477: 474: 460: 458:Unclassified 456: 452: 449: 448: 444: 441: 437: 433: 430: 429: 425: 422: 418: 414: 411: 408: 407: 399: 397: 389: 384: 372: 368: 367:aerosol spray 363: 360: 359: 354: 351: 350: 345: 342: 341: 336: 333: 332: 327: 324: 323: 322: 320: 316: 312: 305:Explosive gas 302: 300: 296: 292: 288: 284: 280: 275: 270: 268: 264: 260: 256: 252: 248: 244: 240: 236: 226: 223: 220: 212: 207: 198: 196: 192: 187: 185: 182:NFPA 70, the 180: 170: 158: 151:North America 143: 141: 137: 132: 130: 124: 121: 117: 112: 110: 106: 100: 98: 94: 83: 81: 77: 73: 69: 65: 61: 57: 53: 49: 45: 41: 32: 19: 2052: 2038: 2024: 2007: 1997:, retrieved 1991: 1985: 1975:, retrieved 1966: 1960: 1946: 1936:, retrieved 1931: 1920: 1910:, retrieved 1904: 1898: 1888:, retrieved 1884:the original 1878: 1872: 1862:, retrieved 1858:the original 1853: 1843: 1824: 1818: 1807:. Retrieved 1780:, retrieved 1774: 1768: 1757:. Retrieved 1747: 1734:. Retrieved 1660: 1648:illumination 1633: 1620: 1616: 1609: 1606: 1583: 1571: 1559: 1509: 1493: 1429: 1404: 1253: 1244: 1240: 1197: 1181:'ic: zone 2 1179:'ib': Zone 1 1147: 1001: 992:Flame proof 978:Description 970: 947:autoignition 924: 902: 888: 770: 762: 753: 749: 731: 720: 709: 695: 684: 673: 662: 539: 535: 516: 482:Description 471: 415:Description 393: 308: 271: 266: 262: 258: 254: 232: 224: 216: 188: 181: 154: 135: 133: 125: 113: 101: 89: 47: 37: 1447:Definition 1054:Oil filled 759:Temperature 450:Division 2 442:Division 1 431:Division 2 423:Division 1 311:hydrocarbon 283:maintenance 243:grain mills 109:ventilation 97:reliability 95:as well as 2070:Categories 1999:2020-07-31 1977:2020-07-31 1938:2020-07-31 1912:2020-07-31 1890:2018-04-04 1864:2018-04-04 1809:2020-08-01 1782:2020-07-31 1759:2020-07-31 1736:2018-04-04 1723:References 1664:inductance 1640:coal mines 1588:, such as 1535:Ex II 1 G 1444:NEMA Type 1382:III (dust) 1365:III (dust) 1348:III (dust) 1343:n, ic, pz 1070:switchgear 789:Germany °C 568:Acetylene 439:Class III 287:electrical 285:, safety, 279:operations 129:converging 40:electrical 1676:Arc flash 1656:fire damp 1644:signaling 1598:CSA Group 1594:FM Global 1285:energized 1282:I (mines) 1012:acetylene 984:Location 981:Standard 958:IEC 60079 894:Equipment 880:T6 - 85 877:T3 - 200 869:T5 - 100 866:T2D - 215 855:T4A - 120 852:T2C - 230 841:T4 - 135 838:T2B - 260 827:T3C - 160 824:T2A - 280 813:T3B - 165 810:T2 - 300 799:T3A - 180 796:T1 - 450 683:Ethylene 672:Hydrogen 584:Ethylene 576:Hydrogen 420:Class II 412:Division 274:plan view 247:elevators 191:CSA Group 146:Standards 99:reasons. 80:Standards 52:explosion 1670:See also 1602:Intertek 1530:Meaning 1490:Labeling 1331:II (gas) 1314:II (gas) 1297:II (gas) 1274:Minimum 1200:Fieldbus 1162:Fieldbus 1156:galvanic 1016:hydrogen 1008:ethylene 975:Ex code 872:T6 - 85 858:T5 - 100 844:T4 - 135 830:T3 - 200 816:T2 - 300 802:T1 - 450 786:(IEC) °C 744:Methane 694:Propane 503:Zone 22 495:Zone 21 487:Zone 20 315:hydrogen 259:division 235:refinery 86:Overview 2051:EEMUA, 1630:History 1624:IP code 1604:(ETL). 1567:Baseefa 1512:CE mark 1309:ia, ma 1263:Ex risk 1211:Zone 2 1004:propane 971:Index 883: 669:IIB+H2 396:explode 319:ammonia 229:Hazards 179:RP505. 175:500 and 127:slowly 48:haz·lōk 2059: 2045: 2031: 1831: 1686:CompEx 1652:motors 1650:, and 1574: 1498:Europe 781:USA °C 647:Group 554:Group 525:, and 409:Class 329:areas. 265:, and 177: 173: 165: 161: 60:vapors 44:safety 1971:(PDF) 1600:, or 1527:Mark 1260:Group 1246:'d'. 940:resin 727:IIIA 716:IIIB 705:IIIC 644:Area 627:None 551:Area 479:Zone 347:time. 295:flows 267:group 255:class 107:, or 56:gases 2057:ISBN 2043:ISBN 2029:ISBN 1829:ISBN 1642:for 1565:and 1563:Sira 1267:Zone 987:Use 691:IIA 680:IIB 658:IIC 317:and 289:and 263:zone 217:The 64:dust 42:and 1476:10 1394:ic 1377:ib 1360:ia 1271:EPL 1154:or 775:): 402:NEC 237:or 70:. 38:In 2072:: 1930:, 1852:, 1790:^ 1646:, 1596:, 1592:, 1590:UL 1468:9 1460:8 1452:7 1391:Dc 1388:22 1374:Db 1371:21 1357:Da 1354:20 1340:Gc 1323:Gb 1306:Ga 1290:Ma 1222:s 1192:n 1142:i 1119:p 1099:m 1079:q 1057:o 1036:e 1018:) 995:d 616:G 608:F 589:D 581:C 573:B 565:A 398:. 297:, 281:, 261:, 257:, 245:, 142:. 62:, 58:, 1954:. 1837:. 1812:. 1762:. 1739:. 1337:2 1320:1 1303:0 1014:/ 1006:/ 20:)

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