EN IEC 60079 Explosive Atmospheres

The “EN IEC 60079 Explosive atmospheres” standard, which is based on a European standard and later published by the International Electrotechnical Commission (IEC), consists of the following subsections published under the same title:

• The standard “EN IEC 60079-0 Part 0: Equipment - General requirements” describes the general requirements for the construction, testing and marking of Ex equipment and Ex components intended for use in explosive atmospheres. The standard atmospheric conditions (related to the explosion properties of the atmosphere) under which it can be assumed that Ex equipment can be operated are:
  • Temperature minus 20 degrees to plus 60 degrees
  • Pressure 80 kPa (0,8 bar) to 110 kPa (1,1 bar)
  • Air with normal oxygen content, typically 21 percent v/v.

This standard and other standards that complement this standard specify additional test requirements for Ex equipment operating outside the standard temperature range, but further assessment and additional testing may be required for Ex equipment operating outside the standard atmospheric pressure range and standard oxygen content. Such additional testing may be important, particularly for types of protection that depend on the extinguishing of a flame, such as flameproof enclosures “D” or energy limitation, intrinsic safety.

• The standard "EN IEC 60079-1 Part 1: Equipment protection by flameproof enclosures "D"" specifies the specific requirements for the construction and testing of electrical equipment with flameproof enclosures of type "D" protection, intended for use in explosive gas atmospheres. This standard supplements and replaces the general requirements of IEC 60079-0. When a requirement of this standard conflicts with a requirement of EN IEC 60079-0, the requirement of this standard takes precedence.
• The standard “EN IEC 60079-2 Part 2: Equipment protection with pressure enclosures “P”” specifies the specific requirements for the construction and testing of electrical equipment with pressure enclosures of type of protection “P”, designed for use in explosive gas atmospheres or explosive dust atmospheres. It also includes requirements for pressure enclosures containing a limited release of flammable substances. This standard supplements and replaces the general requirements of EN IEC 60079-0. Where a requirement of this standard conflicts with a requirement of EN IEC 60079-0, the requirements of this standard take precedence. This standard does not include requirements for:
  • Pressurized enclosures in which the containment system may release air with a higher than normal oxygen content or oxygen combined with inert gas in which the oxygen content is greater than 21 percent.
  • Pressurized chambers or analyzer houses.
  • Pressurized enclosures used where explosives or pyrotechnics are present.
  • Pressure enclosures used where hybrid mixtures of gas/vapor and combustible dusts are present.
  • Pressurized enclosures used in the presence of pyrophoric substances such as explosives or propellants containing their own oxidizers.
  • Pressurized enclosures having an internal release source of combustible dust.
• The standard “EN IEC 60079-5 Part 5: Equipment protection by powder filling “Q”” specifies the specific requirements for the construction, testing and marking of electrical equipment, parts of electrical equipment and Ex components of type “Q” with powder filling, intended for use in explosive gas atmospheres. Electrical equipment and Ex components protected by powder filling “Q” may include electronic circuits, transformers, protection fuses, relays, intrinsically safe electrical devices, associated electrical devices, switches and similar. This standard supplements and replaces the general requirements of EN IEC 60079-0. When a requirement of this standard conflicts with a requirement of EN IEC 60079-0, the requirement of this standard takes precedence. This standard applies to electrical equipment, parts of electrical equipment and Ex components having the following characteristics:
  • Nominal supply current less than or equal to 16 A
  • Nominal supply voltage less than or equal to 1000 Volts
  • Nominal power consumption less than or equal to 1000 W.
• The standard “EN IEC 60079-10-1 Part 10-1: Classification of areas - Explosive gas atmospheres” deals with the classification of areas where flammable gas or vapour hazards may occur and can then be used as a basis to support the appropriate design, construction, operation and maintenance of equipment for use in hazardous areas. It is intended to be applied in areas where there may be a risk of ignition due to the presence of flammable gas or vapour mixed with air, but does not apply to:
  • Mines sensitive to firedamp
  • Processing and manufacturing of explosives
  • Catastrophic failures or rare failures that are beyond the concept of normality addressed in this standard
  • Rooms used for medical purposes
  • Homes
  • Locations where hazards may arise due to the presence of flammable dust or flammable flying materials (but the principles can be used in the assessment of a hybrid mixture).

Flammable vapours may occur or be present simultaneously. In this case, strict application of the details in this standard may not be appropriate. Flammable vapours may also be formed when liquids which are not considered to be hazardous because of their high flash point are released under pressure. In these cases, the classifications and details given in this standard do not apply. Information on flammable vapours is included in the annex to the standard (Annex G).

• The standard “EN IEC 60079-10-2 Part 10-2: Classification of areas - Explosive dust atmospheres” deals with the identification and classification of areas where explosive dust atmospheres and flammable dust layers are present in order to allow the ignition sources in such areas to be adequately assessed. Explosive dust atmospheres and flammable dust layers are treated separately in this standard. It also describes the area classification for explosive dust clouds, with dust layers acting as one of the possible release sources. Other general considerations for dust layers are also described. The examples in this standard are based on an effective cleaning system implemented on site to prevent the accumulation of dust layers. In the absence of effective cleaning, the area classification includes the formation of potentially explosive dust clouds from dust layers. The principles of this standard can also be followed when flammable fibres or flying particles may cause a hazard. This standard is intended to be applied in locations where there may be a risk due to the presence of explosive dust atmospheres or flammable dust layers under normal atmospheric conditions.
• The standard “EN IEC 60079-11 Part 11: Equipment protection with intrinsic safety “I”” describes a procedure for the construction and testing of intrinsically safe devices designed for use in explosive atmospheres and associated devices designed to be connected to intrinsically safe circuits entering such environments. This type of protection applies to electrical equipment in which the electrical circuits themselves are not capable of igniting the surrounding explosive atmosphere. This includes electrical equipment incorporating intrinsically safe circuits only under certain conditions, for example under battery supply with the mains supply disconnected. This standard also applies to electrical equipment or parts of electrical equipment located outside an explosive atmosphere or protected by another type of protection listed in EN IEC 60079-0. Here, the intrinsic safety of electrical circuits in an explosive atmosphere may depend on the design and construction of such electrical equipment or parts of such electrical equipment. Electrical circuits exposed to an explosive atmosphere are assessed for use in such environments by applying this document.
• The standard “EN IEC 60079-13 Part 13: Equipment protection with pressurized rooms “P” and artificially ventilated rooms “V” describes the requirements for the design, construction, evaluation, verification and marking of rooms that are typically used to protect indoor equipment and are protected as follows:
  • Zone 1 or Zone 2 or Zone 21 or Zone 22 explosive atmosphere (Normal equipment protection level An area requiring Gb, Gc, Db or Dc), with no internal gas/vapor release source and protected by pressurization.
  • Located in a zone 2 explosive atmosphere (an area normally requiring equipment protection level Gc), with or without an internal gas/vapour release source and protected by artificial ventilation.
  • Located in a non-hazardous area, containing an internal gas/vapor release source and protected by artificial ventilation.
  • Located in a Zone 1 or Zone 2 or Zone 21 or Zone 22 explosive atmosphere (an area normally requiring equipment protection level Gb, Gc, Db or Dc), having an internal gas/vapor release source and protected by both pressurization and artificial ventilation.
• The standard “EN IEC 60079-14 Part 14: Electrical installation design, selection and installation of equipment, including initial inspection” describes specific requirements, including documentation and personnel qualification requirements, for the design, selection, installation and necessary initial inspection of electrical systems for Ex equipment in or associated with explosive atmospheres. These requirements are in addition to the requirements that apply to facilities in non-hazardous areas.
• The standard “EN IEC 60079-29-1 Part 29-1: Gas detectors - Performance requirements for detectors for flammable gases” specifies the general requirements for construction, testing and performance, and test methods applicable to portable, transportable and fixed equipment for the detection and measurement of flammable gas or vapour concentrations in air. The equipment or its parts are intended for use in explosive atmospheres and in firedamp-sensitive mines. This standard is applicable to flammable gas detection equipment having a measuring range up to any volume fraction declared by the manufacturer and designed to provide an indication, alarm or other output function. Its purpose is to indicate a potential explosion hazard and, in some cases, to initiate automatic or manual protective action. This standard is applicable to equipment, including integral sampling systems for aspirating equipment, intended for use in commercial, industrial and non-residential safety applications.
• The standard “EN IEC 60079-29-2 Part 29-2: Gas detectors - Selection, installation, use and maintenance of detectors for flammable gases and oxygen” provides guidance and recommended practice on the selection, installation, safe use and maintenance of electrically operated Group II equipment designed for use in industrial and commercial safety applications and Group I equipment in underground coal mines for the detection and measurement of flammable gases complying with the requirements of EN IEC 60079-29-1 or EN IEC 60079-29-4. This standard applies to the measurement of oxygen for inertization purposes where explosion protection is achieved by the exclusion of oxygen rather than measuring flammable gases or vapours. This standard is a compilation of practical information to assist the user and applies to equipment, instruments and systems that use the electrical signal from a gas sensor to produce a meter reading, to activate a visual or audible preset alarm or other device, or any combination of these to indicate the presence of a flammable or potentially explosive mixture of gas or vapour with air.
• The standard “EN IEC 60079-29-3 Part 29-3: Gas detectors - Guide to the functional safety of fixed gas detection systems” provides guidance for the design and implementation of a fixed gas detection system, including associated or ambient gas detection equipment, for the detection of flammable gases/vapours and oxygen when used in a safety-related application in accordance with the standards “IEC 61508-1 Functional safety of electrical/electronic/programmable electronic safety-related systems” and “IEC 61511 Functional safety - Safety instrumented systems for the process industry sector - All parts”. This standard also applies to the detection of toxic gases. Other parts of this international standard and relevant local, national and international standards specify the performance requirements for a gas detector and a gas detection control unit separately. These standards are commonly known as metrological performance standards and deal with the accuracy of the measured value, the overall system performance, but not with the device or system integrity from the safety function perspective. This international standard applies to the integrity of the safety function.
• The standard “EN IEC 60079-29-4 Part 29-4 Gas detectors - Performance requirements for open path detectors for combustible gases” describes the performance requirements for equipment for the detection and measurement of combustible gases or vapours in ambient air by measuring the spectral absorption by gases or vapours over extended optical paths, typically from one metre to several kilometres. Such equipment measures the integral concentration of the absorbing gas along the optical path in units such as the LFL meter for combustible gases. True concentration values ​​can only be derived when the concentration can be determined to be uniform along the optical path, for example over very short optical paths (up to 100 mm). In such cases, the equipment is covered by EN IEC 60079-29-1. This standard is based on existing absorption techniques using infrared radiation. Other techniques and applications may require additional testing considerations (e.g. pressure testing). The equipment covered by this standard is classified into the following types:
  • Type 1: An optical transmitter and receiver located at either end of a path through the atmosphere to be monitored.
  • Type 2: An optical transceiver (i.e., combined transmitter and receiver) located at each end of a path in the atmosphere to be monitored and a suitable reflector, which may be a topographic feature or a retroreflector.

This standard also applies if an equipment manufacturer makes any claim regarding any special construction feature or superior performance that exceeds the minimum requirements of this standard. All such claims shall be substantiated and test procedures shall be extended or supplemented as necessary to verify the claimed performance. Additional tests shall be agreed upon between the manufacturer and the testing laboratory and shall be identified and described in the test report.

Our organization, which has been trying to support businesses from every sector with its testing, measurement, analysis and evaluation studies carried out in a wide range for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services in accordance with the "EN IEC 60079 Explosive atmospheres" standard are also provided to businesses.