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IEC, NEC, CEC, ATEX Hazardous Location Guide
EGS Electrical Group
9377 W. Higgins Road
Rosemont, IL 60018
1.800.621.1506
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Hazardous Area Location Guide - IEC NEC CEC & ATEX By Emerson Industrial

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Hazardous Area Location Guide - IEC NEC CEC & ATEX By Emerson Industrial

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Hazardous Area Location Guide - IEC NEC CEC & ATEX By Emerson Industrial

  1. 1. IEC, NEC, CEC, ATEX Hazardous Location Guide EGS Electrical Group 9377 W. Higgins Road Rosemont, IL 60018 1.800.621.1506 www.egseg.com Canada 888.765.2226 Mexico 52.55.5809.5070 Asia/Pacific 65.6891.7600 China 86.21.5426.0668 Middle East 971.4.8838.831 Europe 33.1.4817.8502 South America Nutsteel Indústria Metalúrgica Ltda. São Paulo/SP – Brazil 55.11.2122.5777 Macaé/RJ – Brazil 55.22.2770.4686 Camaçari/BA – Brazil 55.71.3623.2028 CHART 14 — IEC Protection Techniques for Hazardous Areas FLAMEPROOF “d” • ZONE 1 • Contain internal explosion • Control external temperature of enclosure • Similar to NEC® explosionproof • Usually cast enclosure • Typical use in lighting and motor starters REQUIREMENTS: • Internal explosion cannot be transmitted outside enclosure • External temperature of enclosure below ignition temperature of surrounding gases • Cable fittings must have 5 threads engaged • Internal and external ground screw Increased safety “e” • ZONE 1 • High impact resistant enclosures—FRP, GRP, sheet steel/aluminum, stainless steel • Enclosure will not hold static charge • Maintain minimum of IP 54 ingress protection • Apparatus non arcing/sparking • Typical use in terminal enclosures REQUIREMENTS: • Use IEC approved non-loosening screw type in IEC approved enclosures • Control internal and external temperature FLAMEPROOF PLUS INCREASED SAFETY “de” “d” “e” • ZONE 1 • Location of arcing has “d” protection (flameproof) • Connection terminals have “e” protection (increased safety) • Typical use in switches, lighting, controls, plugs and receptacles/sockets Items such as power outlets, switches, some lighting, etc., cannot be protected by “e” mode only. In this case “d” and “e” are combined. REQUIREMENTS: • Area where arc can be produced is “d” or flameproof in a restricted volume enclosure - often contact blocks and switches • Area with connection terminals is “e” or increased safety • Controls internal and external temperatures INTRINSIC SAFETY “ia” - “ib” - “ic” • ia ZONE 0 • ib ZONE 1 • ic ZONE 2 • Incapable of releasing enough energy to cause an explosion • Typical use in communication equipment REQUIREMENTS: • Install in safe areas (non IS), or in an approved “d” enclosure • Energy limiting barriers • Transmits signal from hazardous area (IS) • Prevents energy release • Ensure isolation of circuits between IS and non IS areas Encapsulation “m” • ZONE 1 • Epoxy or other resin to totally seal arcing and sparking devices • Typical use in lighting controls and sealed switches REQUIREMENTS: • Arcing and sparking devices totally immersed by epoxy or other resin • IEC approved non-loosening connectors • Controls internal and external temperatures NON-SPARKING “n” • ZONE 2 • Enclosure restricts ingress of hazardous gases • nA=non sparking construction • nR=restricted breathing • nC=hermetically sealed, non incendive • Typical use in lighting fixtures REQUIREMENTS: • Equipment has no normally arcing parts • Thermal effects incapable of ignition • nA=non sparking • nR=restricted breathing • nC=hermetically sealed non incendive OIL IMMERSION “o” • ZONE 1 • Oil totally seals arcing and sparking devices • Typical use in hazardous rated transformers and switches REQUIREMENTS: • Arcing and sparking devices totally immersed by oil • IEC approved non-loosening connectors • Controls internal and external temperatures PRESSURIZED APPARATUS “p” • ZONE 1 • Expels ignitable vapor/gas • Maintains positive enclosure pressure REQUIREMENTS: • Install in safe areas (non IS), or in an approved “d” enclosure • Energy limiting barriers • Transmits signal from hazardous area (IS) • Prevents energy release • Ensure isolation of circuits between IS and non IS areas POWDER FILLING “q” • ZONE 1 • Finely ground powder to totally seal arcing and sparking devices • Typical use in lighting, controls and sealed switches REQUIREMENTS: • Arcing and sparking devices totally immersed by finely ground powder • IEC approved non-loosening connectors • Controls internal and external temperatures CHART 15 — IEC Protection Techniques for Areas With Combustible Dust INTRINSIC SAFETY “iD” • iaD for use in ZONE 20, 21, 22 • iaD for use in ZONE 21, 22 • (Ex ibD) associated electrical apparatus - installation in the safe areas • Incapable of releasing enough energy to cause an explosion • Typical use in communication equipment REQUIREMENTS: • Install in safe areas (non IS), or in an approved “d” enclosure • Energy limiting barriers • Transmits signal from hazardous area (IS) • Prevents energy release • Ensure isolation of circuits between IS and non IS areas ENCAPSULATION “mD” • maD for use in ZONE 20, 21, 22 • mbD for use in ZONE 21, 22 • Epoxy or other resin to totally seal arcing and sparking devices • Typical use in lighting, controls and sealed switches REQUIREMENTS: • Arcing and sparking devices totally immersed by epoxy or other resin • IEC approved non-loosening connectors • Controls internal and external temperatures PRESSURIZATION “pD” • ZONE 21, 22 • Expels ignitable vapor/gas • Maintains positive enclosure pressure REQUIREMENTS: • Install in safe areas (non IS), or in an approved “d” enclosure • Energy limiting barriers • Transmits signal from hazardous area (IS) • Prevents energy release • Ensure isolation of circuits between IS and non IS areas PROTECTION BY ENCLOSURES “tD” • tD A21 Procedure A for ZONE 21 • tD B21 Procedure B for ZONE 21 • High impact resistant enclosures—FRP, GRP, sheet steel/aluminum, stainless steel • Enclosure will not hold static charge • Maintain minimum of IP 54 ingress protection • Apparatus non arcing/sparking • Typical use in terminal enclosures REQUIREMENTS: • Use IEC approved non-loosening type enclosures • Control internal and external temperature CHART 1 — What is aN IEC zone? The IEC has defined 3 areas of hazardous gas or vapor release as follows: ZONE 0 ZONE 1 ZONE 2 Explosive Atmosphere Is Continuously Present Explosive Atmosphere Is Often Present Explosive Atmosphere May Accidentally Be Present 1000 hours/year 10-1000 hours/year 0.1 - 10 hours/year Zone in which an explosive mixture of gas, vapor or mist is continuously present. Zone in which an explosive mixture of gas, vapor or mist is likely to occur during normal operation. Zone in which an explosive mixture is not likely to occur in normal operation, and if it occurs will only exist for a short time (leaks or maintenance). The IEC has defined 3 areas of hazardous/combustable dusts as follows: ZONE 20 ZONE 21 ZONE 22 Explosive Atmosphere Is Continuously Present Explosive Atmosphere Is Often Present Explosive Atmosphere May Accidentally Be Present 1000 hours/year 10-1000 hours/year 0.1 - 10 hours/year Zone in which an explosive mixture of dust is continuously present. Zone in which an explosive mixture of dust is likely to occur during normal operation. Zone in which an explosive mixture of dust is not likely to occur in normal operation, and if it occurs will only exist for a short time (leaks or maintenance). CHART 12 — Understanding the Ingress Protection System IP The IEC IP classification system designates the degree of protection provided by an enclosure against impact and/or water or dust penetration (ingress). It has two numbers; first—protection against solid objects, second protection against liquid. EXAMPLE:  IP 54 1st Figure: protection against solid bodies 2nd Figure: protection against liquids IP TESTS IP TESTS 0 No protection 0 No protection 1 Protected against solid bodies larger than 50mm (e.g. accidental contact with the hand) 1 Protected against vertically-falling drops of water (condensation) 2 Protected against solid bodies larger than 12.5mm (e.g. finger of the hand) 2 Protected against drops of water falling at up to 15˚ from the vertical 3 Protected against solid bodies larger than 2.5mm (tools, wires) 3 Protected against drops of rainwater at up to 60˚ from the vertical 4 Protection against solid bodies larger than 1mm (fine tools, small wires) 4 Protected against projections of water from all directions 5 Protected against dust (no harmful deposit) 5 Protected against jets of water from all directions 6 Completely protected against dust 6 Completely protected against jets of water of similar force to heavy seas 7 Protected against the effects of temporary immersion 8 Protected against effects of prolonged immersion under specified conditions Glossary AEx Symbol designates equipment built to NEC® standards for use in NEC® Zone designated areas. Such products are not suitable for use in ATEX or IEC Ex applications. ATEX ATmosphères EXplosibles – Organizations in the EU where ‘explosion risk’ exists, must use the guidelines for protecting the employees of the companies. Manufacturers who apply its provisions and affix the CE marking are able to sell their equipment anywhere in EU without any further requirements being applied with respect to the risks covered being applied. CEC Canadian Electric Code. CENELEC European Committee for Electrical Standardization. CENELEC develops electrotechnical standards that are adopted as Euronorms by the EU for electrical and electronic goods and services. It is comprised of a group of 31 European countries and 11 affiliated countries that have CENELEC standards based on the parallel working IEC/CENELEC. Class I Term used in NEC® to describe locations in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures. Class II Term used in NEC® to describe locations that are hazardous because of the presence of combustible dust. Class III Term used in NEC® to describe locations that are hazardous because of the presence of easily ignitable fibers or flyings but in which such fibers or flyings are not likely to be in suspension in the air. CSA Canadian Standard Association - Provider of product testing certification services for US, Canada and countries worldwide, for electrical, plumbing, gas mechanical products. Division 1 Term used in NEC® to describe the condition in which the hazard can be present during normal conditions. Division 2 Term used in NEC® to describe the condition in which the hazard is present only under abnormal conditions. CHART 13 — Approximate Conversion of NEMA Enclosure Type Ratings to IEC 60529 Enclosure Classification Designations (IP) (Cannot be Used to Convert IEC classification Designations to NEMA Type Ratings or vice versa) IP First Character NEMA Enclosure Type IP Second Character 1 2 3, 3X, 3S, 3SX 3R. 3RX 4, 4X 5 6 6P 12, 12K, 13 IP0_ IP_0 IP1_ IP_1 IP2_ IP_2 IP3_ IP_3 IP4_ IP_4 IP5_ IP_5 IP6_ IP_6 IP_7 IP_8 A B A B A B A B A B A B A B A B A B A = A shaded block in the “A” column indicates that the NEMA Enclosure Type exceeds the requirements for the respective IEC 60529 IP First Character Designation. The IP First Character Designation is the protection against access to hazardous parts and solid foreign objects. B = A shaded block in the “B” column indicates that the NEMA Enclosure Type exceeds the requirements for the respective IEC 60529 IP Second Character Designation. The IP Second Character Designation is the protection against the ingress of water. Example of Table Use: An IEC IP 45 Enclosure Rating is specified. What NEMA Type Enclosures meet and exceed the IP 45 rating? Referencing the first character, 4, in the IP rating and the row designated “IP4_” in the left most column in the table; the blocks in Column “A” for NEMA Types 3, 3X, 3S, 3SX, 3R, 3RX 4, 4X, 5, 6, 6P, 12, 12K and 13 are shaded. These NEMA ratings meet and exceed the IEC protection requirements against access to hazardous parts and solid foreign objects. CHART 3 — AREA CLASSIFICATION—IEC vs NEC® /CEC (CLASS/DIVISION/GROUP) Inflammable Material IEC/CENELEC NEC® /CEC Gases and Vapors Protection Zone Group Sub- division Class Division Group Acetylene d and/or e 1 or 2 II C I 1 or 2 A Hydrogen d and/or e 1 or 2 II B + H2 I 1 or 2 B Propylene oxide, Ethyl oxide, Butadiene d and/or e 1 or 2 II B I 1 or 2 B Cyclopropane, Ethyl ether, Ethylene d and/or e 1 or 2 II B I 1 or 2 C Acetone, Benzene, Butane, Propane, Hexane, Paint solvents, Natural gas d and/or e 1 or 2 II A I 1 or 2 D CHART 8 — Simplified…Where to Use Equipment listed/marked for: Use—as Noted NEC® Class I, Div. 1 OK for use in NEC® Class I, Zone 1 and 2 NEC® Class I, Div. 2 OK for use in NEC® Class I, Zone 2 NEC® Class I, Zone 1 NOT OK for use in NEC® Class I, Div. 1 NEC® Class I, Zone 2 OK for use in NEC® Class I, Div. 2 NEC® AEx OK for NEC® Zone 0, 1, 2 as marked NEC® AEx NOT suitable for NEC® Class I, Div. 1 NEC® AEx OK for use in NEC® Class I, Div. 2 IEC Zone 1 NOT suitable for any NEC® area IEC Zone 2 NOT suitable for any NEC® area IEC Ex or CENELEC EEx NOT suitable for any NEC® area CHART 7 — Examples of NEC® /CEC CLASS I, DIVISION 1 and 2 SITUATIONS CLASS I, DIVISION 1 CLASS I, DIVISION 1 AND 2 NON CLASSIFIED EXAMPLE 1 CONDITIONS:  Class I, Division 1 hazard exists during normal operation conditions • Open air mixing tank • Products stored in work area  Area classified based on properties of vapors present  Electrical equipment must use approved Div. 1 NEC® protection techniques and wiring methods EXAMPLE 2 CONDITIONS:  Division 2 area can exist where vapors are normally in closed system or containers  Division 1 and 2 areas separated by barrier or space (transition zone) • Hazardous areas properly documented • Div. 2 must use approved NEC® wiring methods and products  Stored products outside Div. 1 work area  Non hazardous area EXAMPLE 3 CONDITIONS:  Closed tank and piping confines Div. 1  Yellow area qualifies as Div. 2  Stored products not present  Purged/pressurized control room qualifies as “non hazardous” is sealed off from Div. 2 area  Electrical equipment in Div. 2 must use approved Div. 2 protection techniques and products CHART 6 — Examples of IEC zone classification SITUATIONS ZONE 0 ZONE 1 ZONE 2 NON HAZARDOUS ZONE EXAMPLE 1 CONDITIONS:  All manual ventilation  Zone 0 area  Zone 1 area  Non hazardous area • Open air mixing tank • No mechanical ventilation • Products stored in work area EXAMPLE 2 CONDITIONS:  Hood over tank  Zone 0 area  Zone 1 area  Zone 2 area  Non hazardous area  Mechanical ventilation  Stored products separated from work area EXAMPLE 3 CONDITIONS:  Tank closed  Mechanical ventilation  Zone 0  Zone 2  Non hazardous area • Operations control outside zones CHART 5 — Groups and subgroups classification — IEC Groups Subgroups Typical Substance Application/Definition Group I I Methane Electrical Equipment for use in mines susceptible to firedamp (Not applicable to ATX Series Products) Group II IIA Propane Electrical equipment for use in places with an explosive gas atmosphere IIB Ethylene IIC Hydrogen Group III (new) IIIA Combustible flyings Electrical equipment for use in places with an explosive dust atmosphere IIIB Non-conductive dust IIIC Conductive dust CHART 2 — COMPARING IEC ZONES AND NEC® /CEC DIVISIONS ZONE 0 / zONE 20 Zone 1 / zONE 21 ZONE 2 / zONE 22 Division 1 Division 2 CHART 4 — IEC vs NEC® /CEC TEMPERATURE CLASSIFICATION COMPARISON Max. Surface Temp. (°C) 85 100 120 135 160 165 180 200 215 230 260 280 300 450 IEC Classification T6 T5 T4 T3 T2 T1 North American Classification T6 T5 T4A T4 T3C T3B T3A T3 T2D T2C T2B T2A T2 T1 CHART 9 — Equipment MARKINGS UNDERSTANDING IEC MARKINGS † Ex de II C T6 Gb ‡ Ga for zone 0 Gb for zone 1 Gc for zone 2 Temperature Class T6 = Max 85˚°C Surface TemperatureGas Subdivision Group-C = Acetelyne Group II = Surface Equipment Group I = Mines Type of Protection d = “flameproof” Type of Protection e = “increased safety” Explosion Protected Meets IEC Standards AEx = Equipment conforms to NEC® † Alternate marking: Ex deb IIC T6. ‡ This only applies to IEC Standards only. See “Chart 10 — Understanding IEC Equipment Protection Level Requirements” below. UNDERSTANDING NEC® /CEC MARKINGS Class I Division 1 Group A A = Acetylene I = Gas and Vapors 1 = Hazard normally present B = Hydrogen II = Dust 2 = Hazard abnormally present C = Ethylene III = Fibers and Flyings D = Gasoline E = Electrically Conductive Dust F = Fuel Dust G = Grain Dust UNDERSTANDING ATEX MARKINGS (Directive 94/9/EC) * • • • II 1 G CE Marking Symbol ID No. of Notified Body of the QA System EU Explosive Atmospheres Symbol Surface (non-mining) Equipment Equipment Category Type of Flammable Substance Ex ia IIC T4 Ga Ex: Conformity to IEC and ATEX Hazardous area standards; Suitability for use in IEC and ATEX hazardous locations Protection Method (intrinsic safety) Gas Group (acetylene hydrogen) Temperature Class Equipment Level Protection: Ga for zone 0 Gb for zone 1 Gc for zone 2 * See “Chart 11 — ATEX Equipment Category” below. CHART 11 — ATEX Equipment Category The ATEX directive adds “The Equipment Category” to the marking which indicates the level of protection which correlates back to the manufacturers quality assurance requirements as shown on this chart. Equipment Group Equipment Category and Level of Protection Presence or Duration of Explosive Atmosphere Flammable Substances Correlation with Hazardous Areas I - Mines M1 - Very high level of protection Continuos Presence Methane, Combustible Dust M2 - High level of protection II - Surface 1 - Very high level of protection Continuous Presence G - Gas, Vapors D - Dust Zone 0 (Gas etc.) Zone 20 (Dust) 2 - High level of protection Likely to Occur Zone 1 (Gas etc.) Zone 21 (Dust) 3 - Normal level of protection Unlikely to Occur Zone 2 (Gas etc.) Zone 22 (Dust) Glossary Ex Designation for hazardous location equipment complying to IEC and ATEX standards. Flameproof An IEC or European term using “containment” protection. Similar to, but not exactly the same as US “explosionproof”. Group Class I: Term used in NEC® to define a collection of gases with similar physical properties such as maximum explosion pressure. Class II: Term used in NEC® to define a collection of hazardous dusts with similar physical characteristics such as ignition temperature as well as attributes such as blanketing effect on equipment. Class III: There are no Group listings. Hazardous Location Exists when a manufacturing, storage or handling process provides a fuel, consisting of a flammable gas, combustible dust, combustible flying or fiber, or some combination of these three elements; and these flammable components can be mixed with enough oxygen from the ambient air to form an explosive atmosphere between the Lower Explosive or Flammable Limit (LEL/LFL) and the Upper Explosive or Flammable Limit (UEL/UFL). IEC International Electrotechnical Commission - International Standards and conformity assessment for all electrical, electronic and related technologies. IECEx International Electrotechnical Commission Explosive Atmospheres - An IECEx Scheme provides a means for manufacturers of EX equipment to obtain Ex certificates of conformity that will be accepted at national level in all participating countries. NEC® National Electric Code - Governs the installation of electrical conductors, equipment, and raceways. Subdivision Zone system grouping of various gas/vapors roughly equal to NEC® “Group”. UL Underwriters Laboratories - A US testing and certification organization. Zone Defines conditions under which explosive gases are present in an area. Zones are similar to divisions, but are generally based on length of time hazardous material may be present. Chart 10 — UNDERSTANDING IEC Equipment Protection Level Requirements Protection Afforded Equipment Protection Level (EPL) Group Performance of Protection Conditions of Operation Very high Ma Group I Requires two independent means of protection or remains safe when two different malfunctions occur Equipment used in explosive atmosphere Ga Group II Used in Zones 0,1 and 2 Da Group III Used in zones 20, 21, and 22 High Mb Group I Good for use in normal and severe operating conditions Equipment de-energized in explosive atmosphere Gb Group II Good for use in normal operation or where equipment malfunctions are considered Used in Zones 1 and 2 Db Group III Used in Zones 21, and 22 Enhanced Gc Group II Good for normal operation Used in Zones 2 Dc Group III Used in zones 22

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