Practical guide to explosion protection Information, planning instructions, selection help VENTILATOREN www.maico-ventilatoren.com

Table of contents 1 Physical principles of explosion hazards .................................................................................. 1.1 What is an explosion? ........................................................................................................................... 1.2 Pre-requirements for an explosion ........................................................................................................ 1.2.1 Combustible materials .................................................................................................................. 1.2.2 Explosive atmosphere .................................................................................................................. 2 Legal Bases of Explosion Protection ........................................................................................... 2.1 Where do the requirements come from? ............................................................................................... 2.2 EU Directives for explosion protection ................................................................................................... 2.3 National laws ......................................................................................................................................... l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p 4 4 4 4 5 8 8 9 9 2.4 Standards .............................................................................................................................................. 10 3 Technical principles of explosion protection ........................................................................... 12 3.1 Explosion protection .............................................................................................................................. 12 3.1.1 Primary explosion protection ........................................................................................................ 12 3.1.2 Secondary explosion protection ................................................................................................... 12 3.1.3 Tertiary explosion protection ........................................................................................................ 13 3.2 Explosion groups .................................................................................................................................. 13 3.3 Zone classification ................................................................................................................................ 13 3.4 Device groups and device categories.................................................................................................... 14 3.5 Ignition temperature .............................................................................................................................. 16 3.6 Temperature classes for gases and vapours ........................................................................................ 16 3.7 Ignition temperatures of dusts .............................................................................................................. 17 3.8 Types of protection ................................................................................................................................ 18 3.9 Protection concept for Maico fans ......................................................................................................... 19 4 Practical section / Application examples .................................................................................. 20 4.1 Applications for ventilation systems in areas at risk of explosion ......................................................... 20 4.2 Technical implementation of ventilation systems in areas at risk of explosion ...................................... 22 5 Checklist ................................................................................................................................................. 26 6 Product overview ................................................................................................................................ 30 7 Documentation section .................................................................................................................... 32 8 Addendum / Important terms ......................................................................................................... 37 9 Sources .................................................................................................................................................. 39 n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D 3 y r o t u t a t S i l s e p c n i r p

1.2.2 Explosive atmosphere Limits of explosion of combustible materials An explosive atmosphere is a mixture of air or oxygen with f combustible gases, f vapours, f mist or f dusts, the concentration of which is within the limits of explo- sion. An explosion will not result from too low a concentra- tion (lean mixture) or too high a concentration (rich mixture). In such cases, there is no combustion reac- tion or at the most partial stationary combustion. The range in which an explosion can take place in the event of ignition is defined by an upper and lower limit of explosion. This depends greatly on the combustible material in question. When ignition takes place, the combustion process is transferred to the entire homo- geneous mixture. Limits of explosion of dusts 1.2.2.1 Potentially explosive area A potentially explosive area is a place where a potentially explosive atmosphere may occur. 1.2.2.2 Sources of ignition For an explosive atmosphere to explode, an effective source of ignition is needed. The question of whether a source of ignition is effective and whether it is able to ignite an explosive atmosphere depends mainly on the energy of the source of ignition and the composi- tion of the explosive atmosphere. In applications in workplaces and production process- es, the following sources of ignition may be present, for example: f hot surfaces f naked flames f mechanically generated f electromagnetic waves f ionising radiation f ultrasound f adiabatic compression f exothermic reactions sparks f electrical systems f static electricity f self-ignition f lightning l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D 5 y r o t u t a t S i l s e p c n i r p

Application example: Wall-mounted fans for air extraction Air extraction can prevent the formation of a potentially explosive atmosphere from combustible fluids. To achieve this, the gas/air mix is extracted from the point at which it is produced using DZQ ... Ex e wall-mounted fans. l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p ➀ MLA or MLZ external grille ➁ Explosive atmosphere ➂ EZQ … E Ex e or DZQ … Ex e fan Application example: Airstreams of the ERM 22 Ex e The ERM 22 Ex e fan is approved for the T1-T3 temperature classes and gases of the IIB+H2 explosion group. It can therefore convey an explosive atmosphere with an ignition temperature above 200 °C. Examples include vapours of petrol, diesel or heating oil. ➀ Ventilation duct, provided by custom- er ➁ ELM Ex flexible cuffs ➂ REM Ex reducer ➃ Terminal box ➄ Ceiling, girder ➅ FUM mounting foot ➆ ERM 22 Ex e fan n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D 7 y r o t u t a t S i l s e p c n i r p

2.2 EU Directives for explosion protection Within the EU, explosion protection is specified by two directives: pheres. It is specified in this directive: f Directive 2014/34/EU: equipment and protective systems intended for use in potentially explosive atmospheres. f Directive 1999/92/EC: minimum requirements for improving the safety and health protection of work- ers potentially at risk from explosive atmospheres. Directive 2014/34/EU describes f the obligations of the manufacturers of the prod- ucts, f sets requirements and f lays down rules for placing on the market with the aim of free movement of goods within the EU. The directive is known as the ATEX directive (French abbreviation for ATmosphère EXplosible"). The ATEX directive contains the following specifica- tions: f Conformity assessment procedure f Clustering f Classification into categories f Design and construction of the products f Essential health and safety requirements Directive 1999/92/EC is aimed at employers or oper- ators of installations in areas with explosive atmos- 2.3 National laws The EU/EC Directives require transposition into the respective national laws of the member states for the purpose of harmonising legislation. In essence, they comply with Directive 2014/34/EU. They transpose the safety level described there into national law. All necessary specifications regarding the requirements for the condition and placing on the mar- ket of devices and protective systems, components as well as safety, monitoring and control equipment for hazardous areas are contained in these laws. The transposition of Directive 1999/92/EC into nation- al law contains the material requirements for explo- sion protection. These are essentially documentation obligations, such as the f creation of a risk assessment and an explosion protection document, f the prescribed protective measures against explo- sion hazards, f the zone classification, and f the use of equipment categories in zones. If work equipment is used in areas with a dangerous f obligations of employers to prevent and protect against explosions, f the assessment of explosion risks, f organisational measures (duty of coordination) f the mandatory creation of the explosion protection document The explosion protection document states in particular f that the explosion risks have been identified and evaluated. f that appropriate measures are taken to achieve the objectives of this Directive. f which areas have been classified into zones in accordance with Annex I to the Directive. f which areas are subject to the minimum require- ments laid down in Annex II to the Directive. f that the workplace and work equipment, including warning devices, are designed, operated and main- tained safely. f that arrangements have been made for the safe use of work equipment in accordance with Direc- tive 2009/104/EC (formerly 89/655/EEC). explosive atmosphere or if its use leads to the forma- tion of a dangerous explosive atmosphere, the neces- sary protective measures must be taken in compliance with these laws. In particular, the equipment and protective systems suitable for the respective zone in accordance with Directive 2014/34/EU must be used. These protec- tive measures must be documented in the explosion protection document before the work equipment is used for the first time. The requirements for tests in potentially explosive atmospheres are regulated in the respective law. Accordingly, the operator is obliged to check systems used in potentially explosive atmos- pheres and measures for explosion protection. Systems in hazardous areas are the entirety of the work equipment relevant to explosion protection, including the connecting elements and the parts of the building relevant to explosion protection. The test must be performed both before initial commissioning and recommissioning after changes requiring testing. The tests must be carried out with the aim of ensuring pro- tection against hazards due to explosions and fires at 9 l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D y r o t u t a t S i l s e p c n i r p

The following standards can be used by the operator to obtain the presumption of conformity: EN Standard EN 60079-10-1 IEC Standard IEC 60079-10-1 Explosive atmospheres - Part 10-1: Classification of areas. Explosive gas Title EN 60079-10-2 IEC 60079-10-2 Explosive atmospheres - Part 10-2: Classification of areas - Explosive atmospheres EN 60079-14 IEC 60079-14 EN 60079-17 IEC 60079-17 EN 60079-19 IEC 60079-19 dust atmospheres Explosive atmospheres - Part 14: Electrical installations design, selection and erection Explosive atmospheres - Part 17: Electrical installations inspection and maintenance Explosive atmospheres -- Part 19: Equipment repair, overhaul and reclamation According to the EU Directive 1999/92/EC, an explo- sion protection document is a precondition for setting up and operating a potentially explosive facility. The explosion protection document must contain all necessary information regarding f the classification of zones, f the temperature classes or f the ignition temperatures characteristic of the flam- mable substances and f record the classification of gases and dusts into the appropriate groups. Based on this information, he is able to select devices that are suitable for the application at hand. The data, which can be taken from the technical documentation and the type plate, must be checked for conformity by the operator. In addition, the required conformity markings must be affixed to the product and legible in accordance with the directive. An EU Declaration of Conformity must be enclosed, on which the manufac- turer of the product declares conformity with the ATEX Directive and other applicable directives. Further documents are the operating instructions and safety information of the manufacturers whose information must be included in the risk assessment. The equipment categories and equipment protection levels must therefore be adapted to the respective zone. Similarly, when used in gas atmospheres, the temperature classes of the equipment must match those of the explosive medium. When used in dust atmospheres, the glow and ignition temperature of the medium must be determined, and if there is a risk of a dust cloud forming, the ignition temperature of the dust cloud must be determined. Likewise, if there is a risk of dust layers forming, the maximum layer thick- ness that can occur must be checked. EN 60079-14 should be used to determine the safety factors. The operator must also include ambient conditions in his considerations and check the resistance to chemical, thermal, mechanical influences or humidity of the devices planned for use. Any special operating conditions must be taken from the technical documen- tation of the product or clarified with the manufacturer of the product. The operating temperature range for devices usually specified by the manufacturer is -20 °C to + 40 °C. The normative scope of application of the EN or IEC 60079-0 assumes normal atmospheric conditions and is defined as a maximum range of -20°C to 60°C. Deviating operating conditions must be tested by a notified body. l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D 11 y r o t u t a t S i l s e p c n i r p

3.1.3 Tertiary explosion protection If an explosion cannot be prevented through prima- ry and secondary explosion protection measures, a design solution should be found and used. This may be, for example f decoupling the system components, f a solution to release pressure or f a system to suppress the explosion. 3.2 Explosion groups One of the key pre-requirements for an explosion occurring is the combustible material. There are a number of materials, which under normal circum- stances will only catch fire with great difficulty, but are explosive if mixed with air and present in a particularly small particle size or with a sufficiently high ignition energy (e.g. metal dusts, aerosols). The ignitability of an explosive atmosphere is a characteristic dependent on material. To distinguish between different risk levels, gases and vapours are divided into four explosion groups: I, IIA, IIB, IIC. The ignitability increases from explosion group I to IIC, while the ignition energy required falls. The explosion group I classification is only used in mining. 3.3 Zone classification Areas subject to explosion hazards are split into zones. The aim of this zone classification is to make possible explosion protection which meets require- ments from both a safety technology and economic standpoint. Different zone classifications are used for gas and dust atmospheres. Depending on zone, only certain categories of devices may be used. The same applies to the equipment protection level (EPL). The figure below shows an example of zone classifica- tion for an explosive atmosphere containing gas: Application example: MAICO fans in zone 1 and zone 2 The operating company has split the production and storage sites shown into zone 0, zone 1 and zone 2. The concentration of combustible materials in the room air is reduced through permanent cross-ventila- tion. This reduces the risk of explosion. MAICO EZQ/S 20/4 E Ex e or DZQ … Ex e wall-mounted fans are therefore fitted in zones 1 and 2. Explosion group Typical combustible material I IIA IIB IIC Methane Acetone, petrol, heating oil Town gas, ethylene Hydrogen, acetylene Dusts are categorised by type and electric conductivi- ty in the form of specific electric resistance. Explosion group Combustible material IIIA IIIB IIIC Flammable fluffs Non-conductive flammable dust, specific electric resist- ance >10³ Ω Conductive flammable dust, specific electric resistance ≤ 10³ Ω ➀ EZQ/S 20/4 E Ex e or DZQ … Ex e wall-mounted fans Zone 0 – MAICO fans not appropriate Zone 1 – MAICO fans appropriate Zone 2 – MAICO fans appropriate Zone classification depends on the frequency with which an explosive atmosphere occurs and the var- ious potential risks this brings with it. Depending on the aggregation state of the combustible material, a distinction is also made between f gas, f vapour, f mist and f dust 13 l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D y r o t u t a t S i l s e p c n i r p

Zones and categories Com- bustible materials Presence of combustible material in the potentially explosive area Classifi- cation of potentially explosive areas Level of Protec- tion Device is safe... Gas, mist, liquid Dust Permanent Zone 0 Occasional Zone 1 Rare, only briefly Permanent Zone 2 Zone 20 Occasional Zone 21 Rare, only briefly Permanent Methane, coal dust Methane, coal dust Common Zone 22 Coal mining Coal mining Very high ... during normal operations, in the event of foreseeable errors and in the events of rare incidents … during normal operations and in the event of foreseeable errors ... during normal operations Normal High Very high ... during normal operations, in the event of foreseeable errors and in the events of rare incidents … during normal operations and in the event of foreseeable errors ... during normal operations Normal High Very high ... during normal operations, in the event of foreseeable errors and in the events of rare incidents … until the unit is switched off High Labelling of equipment used required in accordance with ATEX 2014/34/EU IEC/CENELEC Device group Category Equipment protection level (EPL) II II II II II II I I 1G, (1)G Ga 2G, (2)G Gb 3G, (3)G Gc 1D, (1)D Da 2D, (2)D Db 3D, (3)D Dc M1 Ma M2 Mb Link between zone, device category and EPL for device group II: The equipment protection level (EPL) is a level of protection, which is defined for the device. It is based on the probability of ignition. The differences between explosive gas atmospheres, explosive dust atmospheres and explosive atmospheres in mine workings sensitive to firedamp are taken into account. l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D 15 y r o t u t a t S i l s e p c n i r p

3.7 Ignition temperatures of dusts There is no classification into temperature classes for combustible dusts. The ignition temperature differs de- pending on whether the dust is swirled up (as a cloud) or is deposited (as a layer). In the case of a dust cloud, the equipment’s maximum surface temperature may only be 2/3 of the ignition temperature. The ignition temperature of the dust layer should also be noted for dust deposits. This ignition temperature of the dust layer is defined as the smoul- dering temperature and is the lowest temperature of a hot surface, at which a dust layer of 5 mm can catch fire. It is adjusted to the maximum surface temperature of the device using a safety factor of 75 K. Because thermal insulation is greater with a higher layer thickness of dust, the maximum permitted sur- face temperature of the device should be reduced yet further. The diagram on the right is used for calculation purposes and is based on EN 60079-14. Example for calculating the max. surface temperature with dust layers of between 5 mm and 50 mm. If the layer is thicker than 50 mm, the smouldering temperature should be calculated in the lab. The same is true for a layer thickness of more than 5 mm, if the smouldering temperature for a 5 mm layer thickness is less than 250 °C. Lab testing is also needed if the device is filled entirely with combustible dust. At no critical point may the device be hotter than the lower of the two permissible surface temperatures calculated for dust clouds and dust layers. l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D 17 y r o t u t a t S i l s e p c n i r p

3.9 Protection concept for Maico fans One potential source of ignition on Maico fans is their hot surface, which is produced by the motor’s power loss. During normal operation, after a while the surface temperature reaches a stable, uncritical value. try of the mechanical fan parts. These include an air gap to prevent rotating parts from scraping, use of anti-static, temperature- and flame-resistant materials and material pairings in compliance with the relevant standards. Should faults arise, if the impeller is blocked for example, this temperature will however shoot up very quickly. Without protective measures, the ignition tempera- ture of an explosive atmosphere could therefore be reached and an explosion triggered. The motors of the DZ... Ex e fans are therefore fitted with a PTC thermistor embedded in the motor winding in order to monitor the temperature. Once connected to the ther- mistor triggering device MVS 6 or the TMS machine protection relay thermistor, the protection concept is therefore in place. If a particular limit temperature is exceeded, the MVS 6 or TMS shuts down the fan. This reliably prevents the critical temperature from being reached. Further design protective measures are achieved through the choice of material and geome- ➁ Fault (blocked impeller) ➀ Normal operation TU – Maximum ambient temperature TG – Temperature limit TN – Surface temperature during normal operation TZ – Ignition temperature The thermistor triggering device must not be located in the ex area. But it does have an effect in the ex area which explains why it is subject to the ATEX directive. When labelling devices in line with this directive, category 2 is therefore placed in brackets to indicate that the device has an effect in zone 1 and/or 2. A PTC thermistor is not fitted in the single-phase devices of the ERM Ex e and EZ Ex e-series. A motor protec- tion switch, such as the MVEx, should be used here to deliver the protection concept. This monitors the motor current, which rises should a fault occur, resulting in a hot surface. Like the thermistor triggering device, the motor protection switch should also be installed in the non-potentially explosive area. l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D 19 y r o t u t a t S i l s e p c n i r p

Application example: ERM Ex t ventilation solution in the production of textiles with explosive dust atmospheres Duct fans are used to directly and efficiently extract the fine textile dust, made up of many different materials, such as plastic and natural yarns. The production area remains free of a flammable air mix. The system opera- tors breathe clean air, free from fine dust, while working on the machine. l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p ERM Ex t ➀ ERM Ex t for air extraction ➁ Mix of textile dust and air ➂ Exhaust air ➃ Folded spiral-seams duct Application example: Milling system with explosive dust atmosphere Different zone classifications are used for dust atmospheres. Depending on the zone, only certain device categories may be used. ➀ EZQ/S ... E Ex t or DZQ … Ex t wall-mounted fans ➁ ERM … Ex t duct fan Zone 21 – MAICO fans appropriate. Zone 22 – MAICO fans appropriate.. n n o o i i t t c c e e s s l l a a c c i i t t c c a a r r P P n n o o i i t t a a c c i i l l p p p p A A l l s s e e p p m m a a x x e e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D 21 y r o t u t a t S i l s e p c n i r p

A series of technical measures have proved to deliver effective ventilation: Cross-ventilation With cross-ventilation, the supply air flows through the entire room before being extracted. The supply air should be blown in near the ceiling and in parallel with it. The induction effect distributes the supply air throughout the room. The exhaust air is extracted near the floor because most combustible gases and vapours are heavier than air. One exception is hydrogen, which collects under the ceiling, for example (see “Cross-ventilation in battery rooms appli- cation example”). l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p ➀ EZQ … E Ex e or DZQ … Ex e wall-mounted fan ➁ Air flow during cross-ventilation ➂ Explosive atmosphere ➃ ERM … Ex e duct fan ➄ Exhaust Air ➀ DZD … Ex e roof fan ➁ Supply air during cross-ventilation ➂ Explosive atmosphere ➃ DZR … Ex e duct fan ➄ ERM … Ex e duct fan n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D In the applications shown above, the supply air is blown into the room in parallel to the ceiling. As the supply air crosses the room, it mixes well with the air already present in the room. It is then extracted either directly at the workplace, in a dangerous material cabinet with ventilation connected up directly or generally using exhaust air fans near the floor. 23 y r o t u t a t S i l s e p c n i r p

Exhaust air / air extraction system Depending on the industry in question, the removal of exhaust air from the building has to meet different requirements. For example, the following applies to exhaust air exiting painting systems: f The exhaust duct opening must be at least 2 m above the ridge of a pitched roof or 5 m above flat roofs. f The exhaust duct opening must be at least 10 m above the ground. f The exit speed of the exhaust air must be at least 7 m/s. f In the case of air extraction systems, an appropriate overrun time must be used to ensure that an explosive atmosphere cannot form even once the actual activity is complete. Folded spiral-seams ducts are used in the ventilation ducts here. Standard plastic ducts may not be used due to the risk of electrostatic charges. Special electrically conductive plastic ducts may however be used. l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p ➀ Explosive atmosphere ➁ Exhaust opening for exhaust air ➂ DZD … Ex e roof fan ➃ ERM … Ex e duct fan ➄ Outgoing air n n o o i i t t c c e e s s l l a a c c i i t t c c a a r r P P n n o o i i t t a a c c i i l l p p p p A A l l s s e e p p m m a a x x e e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D 25 y r o t u t a t S i l s e p c n i r p

2 7 Statutory principles Documentation Product overview Checklist Practical section Practical section Application Application examples examples Technical principles Legal principles Physical principles

The following factors also come into play when selecting the right fan: Air medium Airstream temperature Rated voltage With adjustable speed (no control) Application example MAICO provides: For all neutral and slightly acidic/alkaline vapours and gases of groups IIA, IIB and hydrogen. IIIA Flammable fluffs IIIB Non-conductive flammable dust, specific electric resistance >10³ Ω Not for use with abrasive media. -20 °C ≤ Ta≤ + 50 °C -20 °C ≤ Ta≤ + 40 °C 400 V 50/60 Hz (Special 125-500 V devices possible) 230 V 50/60 Hz (Special 100-250 V devices possible) Yes, with the exception that DZ... 35/2 B Ex e, ERM... Ex and EZQ... E Ex e does not offer speed adjustment Applicable for: All product groups of the gas ex fans All product groups of the dust ex fans ERM… Ex DZS ... B Ex e, DZQ ... B Ex e, DZR ... B Ex e, DZD … B Ex e DZS / DZQ / DZR / DZD … B Ex e ERM... Ex, EZQ/EZS... Ex DZS /DZQ /DZR /DZD … B Ex e The customer is looking for a fan for the following potentially explosive area: f Zone 1 f Medium: acetaldehyde, ignition temperature 155°C, temperature class T4, gas from group IIA f Installation location: duct system All MAICO fans for areas subject to explosion hazards may be used in zone 1. Example for ERM ex fans Fan ERM 18 Ex e ERM 22 Ex e ERM 25 Ex e Temperature class T1 to T4 T1 to T3 T1 to T3 Can be used? x l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n n o o i i t t c c e e s s l l a a c c i i t t c c a a r r P P n n o o i i t t a a c c i i l l p p p p A A l l s s e e p p m m a a x x e e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D 29 y r o t u t a t S i l s e p c n i r p

st e u r atu m: d r e diu p s m s e cla e m T w e m o Air fl olu v e g olta d v ate R ble olla ntr o c d e e p S Features of fans for areas subject to explosion hazards (medium: gas)  Approved for Zone 1 and 2  Device category 2 G  Pumped medium (gas): for neutral and slightly acidic/alkaline vapours and gases of group IIA, IIB and hydrogen  Usage temperatures: DZ-/EZ: of –20°C ≥ Ta ≥ +40°C. ERM: of –20°C ≥ Ta ≥ +50°C. Features of fans for areas subject to explosion hazards (medium: dust)  Approved for Zone 21 and 22  Device category 2 D  Pumped medium (dust): for non-conductive and non-abrasive dusts of group IIIB or IIIA  Usage temperatures: DZ-/EZ: of –20°C ≥ Ta ≥ +40°C. ERM: of –20°C ≥ Ta ≥ +50°C. Fans for areas subject to explosion hazards (medium: dust) with ignition protection type "t" Ingress of dust is prevented by the tightness of the enclosure. This means that ignitable equipment can be installed in the enclosure. The temperature at the enclosure must not ignite the surrounding atmosphere. l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D The wall fans EZQ / DZQ with square wall plate are also available in the version with steel wall ring. y r o t u t a t S 31 i l s e p c n i r p Fans for areas subject to explosion hazards (medium: gas and dust)400 V230 Vyesno200°C440 – 9.450 m³/hll135°Cll135°Cll200°Cll135°Cll135°Cll200°Cll200°Cll135°Cll200°Cll200°Cll135°Cll135°Cll135°Cll135°Cll135°Cll200°Cll200°Cll135°C980 – 9.370 m³/hll200°Cll135°Cll135°Cll200°Cll200°Cll135°Cll200°Cll200°Cll135°Cll135°Cll135°Cll135°Cll135°Cll200°Cll200°Cll135°C310 – 870 m³/hll200°Cll200°Cll200°C800 – 6.510 m³/hll135°Cll135°Cll200°Cll200°Cll135°Cll200°Cll200°Cll135°Cll135°Cll135°Cll200°Cll200°Cll

Alongside its ATEX certification prescribed by law, Maico also holds IECEx certification. This means that its products can also be supplied outside the European common market. The prerequisite is that the technical and statutory requirements of the destination country comply with those of the products. How does IECEx work? The IECEx system is part of the International Electrotechnical Commission, which is the world’s leading organi- sation for the development of electrotechnical and similar standards. The main job of the IEC is f to develop and maintain international standards and f to check the conformity of electrical products and also f to check quality management in conjunction with the standards produced. l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D Figure 1: Structure of the IECEx system 33 y r o t u t a t S i l s e p c n i r p

There are various services within the IECEx system: l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p Figure 3: IECEx services The IECEx equipment scheme involves the assessment of products for explosive areas. In order to receive this certificate, the manufacturer sends a test sample of his application to the IECEx Certification Body (ExCB), where the sample is tested in the lab. The manufacturer’s production facilities are also audited by the ExCB. Repeat audits ensure that the strict normative requirements of the IEC standards which have to be applied are observed on a continual basis. The sample test results in the technical report (ExTR), which documents that the product has been tested and found to meet all relevant IEC or ISO standard requirements. This applies both to the requirements of electrical equipment, which are covered by IEC 60079 and the 61241 series of standards as well as non-electrical equipment, covered by the ISO/IEC 80079 series of standards. n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D Figure 4: IECEx certification process for equipment for use in explosive environments 35 y r o t u t a t S i l s e p c n i r p

8 Addendum / Important terms Air extraction Device category Air extraction at the exit point (e.g. edge extraction on open containers) prevents explosive substances from being distributed throughout the room. Combustible materials Combustible materials are all substances, which are classified as flammable or highly flammable. These may be gases, liquids and dusts of combustible solids. Detonation Detonation is an explosion under optimum conditions. The resultant pressure wave propagates in the super- sonic range. Explosion An explosion is a sudden oxidation reaction occurring with a sudden increase in temperature, pressure or both at the same time. An explosion produces pres- sure waves with high excess pressure. Explosive atmosphere A mixture of air or oxygen with combustible gases, vapours, mist or dusts under atmospheric conditions. Should this catch fire, the combustion spreads to the entire unburnt mix. Potentially explosive area A place where an explosive atmosphere may occur. Explosion protection document Whenever an explosive atmosphere is reasonably likely to occur, an explosion protection document must be produced. This should provide an overview of the results of the evaluation of the danger and the result- ing technical and organisational protective measures for a system. Flash point Lowest temperature at which an immediately flamma- ble gas or vapour/air mix forms above a liquid under prescribed normal conditions. Device group Electrical equipment for use in potentially explosive at- mospheres are split into 2 groups: f Group 1: Electrical equipment intended for use un- derground in areas at risk of mine gas (not includ- ed in MAICO’s product range). f Group II: Electrical equipment in all other potential- ly explosive areas. Depending on risk, electrical equipment of device group II is split into three device categories. For gases, these are f Category 1G, (1)G offering adequate safety in the event of infrequent errors f Category 2G, (2)G offering adequate safety in the event of foreseeable errors f Category 3G, (3)G offering adequate safety in normal operation For dusts, these are f Category 1D, (1)D offering adequate safety in the event of infrequent errors f Category 2D, (2)D offering adequate safety in the event of foreseeable errors f Category 3D, (3)D offering adequate safety in normal operation Limit of the explosion area An explosion can only occur if the concentration of combustible material is between the upper and lower limit of the explosion area. So an explosive atmos- phere may form inside a partially filled fuel tank, for example, while a full fuel tank is not hazardous. Primary explosion protection measures Prevent the formation and spread of an explosive at- mosphere (e.g. ventilation, inertisation, concentration monitoring with shutdown). Cross-ventilation Supply and exhaust air openings are fitted at opposite ends of the ventilated room. The air then flows through the room before being extracted. Secondary explosion protection measures Prevent sources of ignition from having any effect: Explosion protection for electrical and non-electrical equipment with measures to protect against ignition. Temperature classes Explosive gases can be split into temperature classes on the basis of their ignition temperatures. The maxi- mum surface temperature of equipment (for fans: the motor) must always be lower than the ignition temper- ature of the explosive atmosphere in which it is used. Tertiary explosion protection measures Restrict the impact of an explosion to a safe extent, e.g. using explosion-proof construction, release of pressure, suppression of explosion. 37 l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D y r o t u t a t S i l s e p c n i r p

9 Sources f Heinz Olenik – Elektroinstallation und Betriebsmittel in explosionsgefährdeten Bereichen (Electrical installa- tion and equipment in areas subject to explosion) f R. Stahl – Grundlagen Explosionsschutz (Principles of explosion protection) f https://www.iecex.com/ f https://www.iec.ch/dyn/www/f?p=103:63 f https://www.chemie.de/lexikon/Flammpunkt.html Picture credits and page and item details for licensed images fotolia.com f © Andrei Merkulov, title page centre istockphoto.com f © Natnan Srisuwan, p. 6 image in centre f © kjohansen, p. 6 image at bottom Miscellaneous f © STAHL publication ESSENTIAL EXPLOSION PROTECTION p. 17 f https://www.iec.ch/dyn/www/f?p=103:63, p. 33 f https://www.iecex.com/information/about-iecex/, p. 33 – 36 Information relating to the practical guide to explosion protection f Misprints, errors and technical changes are reserved. f All the texts, photos and graphic designs used in this Practical Guidance are protected by copyright. f We reserve the right to make modifications in line with our policies of continuous improvement. 39 l i a c s y h P l a g e L l i a c n h c e T l i s e p c n i r p l i s e p c n i r p l i s e p c n i r p n o i t c e s l a c i t c a r P n o i t a c i l p p A l s e p m a x e t s i l k c e h C t c u d o r P i w e v r e v o n o i t a t n e m u c o D s e c r u o S