ATEX technical file

Guideline for preparation product technical file for ATEX certification

I-O-20 , VER 00

This guide is based on the following references:

ATEX directive, annex III or module B, part C of paragraph 3
IECEx OD 17: Guide for explosion-proof manufacturers and laboratories to prepare drawings and technical documents for explosion-proof equipment.

Required documents for ATEX technical file

a unique number shall be assigned to technical file.
list of content of technical file
Company introduction
Company registration documents
Certificates of Quality Management, such as ISO 9001, if any
General description for product type
clear identification and description of subset models of product type, if any
clear pictures of product
part list which have formed the equipment or component
data sheets, drawings/circuit diagram (if epplicable) and other needed information for parts and material which have formed the equipment or component
descriptions and explanations necessary for the understanding of above drawings and schemes and the operation of the product.
Results of design calculations made and examination carried out.
user manual of the Ex product
maintenance instructions of the Ex product
list of fully or partially applied harmonized standards and descriptions of solutions used to meet the essential requirements of ATEX Directive where those standards are not applied .
Report of routine tests which may be performed by the manufacturer.
ATEX Certificates of components, if any
EU Declaration of Conformity
Product Risk Analysis Reports according to ATEX 2014/34/EU - Annex II.

Basic Points

The technical file must show the concept of explosion-proof equipment safety, including what type of protection is used for each part of the equipment structure, and what border lines are included and in which parts of the equipment structure.

The requirements stated in this manual do not replace the requirements of the EN 60079 series of standards related to explosion-proof equipment, but clarify and supplement them.
If there are any conflicts between the EU harmonized standards and this guide, the wording in the standard takes precedence.
The drawings and other technical documentation that form the specification of the product used to demonstrate explosion protection conformity are a definitive specification of the product that has been certified.

It is recommended that manufacturers prepare drawings specifically for the purpose of ATEX certification and do not necessarily provide every detail necessary to manufacture the product. When the manufacturer includes typical drawings in the technical file or parts of it, those drawings must specify what information is typical in them.

However, in such cases, to prepare and control the manufacturing drawings, the manufacturer of explosion-proof equipment must have an effective system to control that all the requirements stated in the technical drawings of the explosion-proof file are covered in the manufacturing drawings.

If there is a need to modify the drawings of the explosion-proof equipment after the issuance of the ATEX certificate, the details related to the modification or corrections made on the drawings could be provided only by referring to the initial certificate issued and the relevant notified body.

Changes to the technical file drawings and documents are implemented only after the certification body has issued a revision to the certificate to incorporate the new drawings and documents.

according to definition provided by EN ISO/IEC 80079-34:2020,

schedule drawing: drawing or document listed in the certificate or test report, therefore the drawings exist in ATEX technical file are named schedule drawings.

related drawing: drawing or document not listed in the certificate but linked to the schedule drawing, and used for example, for detailed manufacture or purchase of component parts.
In 7.5.3 of EN ISO/IEC 80079-34:2020, concerning control of manufacturing documents, both the drawings and documentation referred to in this guideline, are referred to as "Schedule Drawings".
It is not sufficient to include statements in drawings and other technical documents that constitute product specifications and merely repeat clauses of relevant explosion-proof standards.e.g. ‘All fasteners require the use of a tool’ – the drawing should clearly show or make reference to a specific fastener.
The language of all drawings and technical documents that make up the technical file must be English or Italian only.
The technical file should be set in the form of non-paper version in the form of conventional format files.

Note: Some manufacturers request to include the seal of the ATEX certification body or other types of approvals on the technical file, which is contrary to the requirements of the certification standard (ISO/IEC 17065) and the ATEX Directive , and it is not possible to fulfill it, because the technical documents are the intellectual assets of the manufacturer and should only be under the control of the manufacturer's own document system, and not the ATEX certification body.

Where a generalized statement is used in the drawings or other technical documents, it should be clear where it is used.For example, a general note stating “All gasket material to be 3 mm thick neoprene rubber” is only valid if the drawing clearly shows the position of every gasket critical to conformity.

In cases where the conformity of a type of material which is indicated in technical file and also used in the construction of explosion-proof equipment is determined only by its performance, the manufacturer must be able to demonstrate during the QAN audit carried out by ATEX certification body that How this requirement is met in the construction of explosion-proof equipment.

For example, material specified “epoxy glass resin with a CTI of greater than 175” would require proof of compliance with the CTI limit for each purchased batch. This can be achieved, for example, by an epoxy manufacturer’s declaration or by a third party.

General requirements for ATEX technical file preparation

Among all essential health and safety requirements (EHSR's) indicated in annex II of ATEX directive, the risk assessment table shall be set only for those risk which have been indicated by the relevant clause of the relevant harmonized standard in annex ZZ of the relevant harmonized standard.

in fact, annex ZZ of each ATEX harmonized standard, includes relation between requirements of the standard and EHSR's of annex II of ATEX directive.

All drawings should be identified by: drawing number, revision number, date of revision, title and name of the design authority in whose drawing record system the drawing is recorded (with relationship to the manufacturer if different).
All measurements given on drawings should be expressed in SI units.
All dimensions relevant to compliance with the standards should be toleranced unless not required by a specific standard.
A drawing/document should show details of marking, including all details required forcompliance with the standards and all specific warning information required by the standards. The layout need not be identical to the layout intended on the final product but should be clear enough to ensure that the final marking is correct. The label material and method of marking and fixing should be provided.
Materials of parts relevant to the type of protection should be unambiguously identified. Where possible, this should be by reference to a material grade given in an IEC or EN standard. Where no relevant IEC or EN standard is available, reference may be made to other nationally, regionally or industry recognised standards. Where no standard is available, or where the standard does not control all relevant requirements, the material manufacturer’s data sheet should be submitted.
For earthing and bonding connections, the connecting method, the construction, parts,dimensions and material specifications including corrosion protection, should be identified.

Note: Bonding is used to reduce the risk of electric shock to anyone who may touch two separate metal parts if there is a fault somewhere in the source of the electrical installation.

For rotating machines, the drawing or document should identify all possible points where clearance of rotating parts is relevant, together with information to determine how the minimum clearances required by the standards are achieved on assembly.
Where applicable, details of mounting and guarding should be provided.
Where ingress protection is relevant, materials of gaskets (and ‘O’ rings) and the method of ensuring or controlling position, adhesion, and compression of the gaskets in service should be clear. Dimensions of gaskets and related features should be specified.
Correctly scaled and dimensioned general arrangement and enclosure drawings including layout should be supplied.

Note: General arrangement drawings show how the components fit together to form the whole equipment. Depending on the complexity of the structure of the explosion-proof equipment, the overall layout plans may include several different plans.

A circuit diagram (single line) including details of external connections should be provided.
Ratings of all protection devices should be specified.

Rating: The maximum amount of current and the maximum amount of voltage that any special electrical equipment can withstand, when it works at its maximum capacity.

Technical description of the equipment and its specification should be provided.
Identification of bearings including conditions of use should be supplied. Bearing data sheets should be provided detailing the working temperatures for the bearings.
The paint or coating applied to the equipment and the maximum thickness should be specified. If the material properties are relevant for static electricity, the paint or coating should be identified and a material data sheet indicating electrical conductivity and breakdown voltage should be provided.
Components which have ATEX component certificates should be identified in the parts list with their ATEX certificate number, or referenced from additional separate documents.
A description of all intended routine tests should be included in the drawings or documentation.

Note: Some details (such as pass criteria) may not be known at the time of submission for certification.

The documentation should specify the environmental conditions for which the equipment is suitable. For example IP rating where applicable.
A document must be provided that defines the parts of the user instructions of the explosion-proof equipment that guarantee safe operation related to explosion protection, including the specific conditions of safe use and the requirements of EN IEC 60079-0:2018, especially clause 1.30.

Note: This document can be the user instructions themselves provided there is sufficient identification of the safety related instructions to enable verification of any changes, for example by placing them in an Annex.

Note: A manufacturer of explosion-proof equipment may change its user instructions following the issuance of an ATEX certificate of conformity, provided that:
1- The changes do not reduce or change the safe performance requirements defined at the time of certification.
2- Changes can be tracked for verification during QAN audits related.
3- Do not change any part or point of the special conditions for use or the schedule of limitations in the user instructions.

Enclosures with opening delay time marking based on surface temperature of enclosed hot components should have schematics/circuit diagrams provided which include component reference designations to correlate with the parts list. The parts list should define the surface temperature of hot components.

Enclosures with opening delay time marking based on charges of enclosed capacitors should have schematics/circuit diagrams provided which include component reference designations to correlate with the parts list. The parts list should define the voltage and capacitances of such capacitors.
Where cells or batteries are included in the equipment, the following should be specified:
- manufacturer's name and part number
- mounting, connection and orientation details
- data sheet from the manufacturer of the cell
- identification of the published IEC or EN cell standards to which the cell complies (this is normally already identified on the cell data sheet)
- details of the construction where cells are combined into a pack
- details of any required marking on the enclosure or battery pack relating to user replacement.
Batteries supplied with existing ATEX certificates require the certificate number, but do not require details of the internals of the battery.
For radio, optical radiating including laser, and ultrasonic equipment, identification and details on threshold power and thermal initiation time and frequency.
Cable/conduit entry points are to be identified and their locations specified.

Special requirements for Exd enclosures

Length of flamepath and maximum flamepath gap for each constructional gap/joint with maximum constructional tolerance. Constructional length of flame path ‘L’ & ‘l’.
Length, size and minimum yield strength (±0.2%) or grade of fasteners. Fastener data and characteristics may be included in a table cross referenced to the applicable drawing(s).
Spacing of boltholes in covers.
Size and tolerance of clearance holes for fasteners. This may be included in a table cross referenced to the applicable drawing(s).

Clearance hole: A hole in a part that is large enough to allow the threads of a screw or bolt to pass through it, but not through the head of the screw or bolt. This hole allows a screw to pass through without the threads entering the material.

More details and information about clearance holes related to screws and bolts can be found in the ISO 273:1979 .

Depth of drilling and tapping. This may be included in a table cross referenced to the applicable drawing(s).
Minimum thickness of material (or metal) around holes. This may be included in a table cross referenced to the applicable drawing(s).
Maximum and minimum diameter of shafts and bores together with maximum “m” and minimum “k” radial clearances of rotating parts.
Location and other specifications of Threaded joints, including entries, including range of sizes and maximum number, pitch, class of fit, length of thread provided in enclosure (chamfers and undercuts taken into account).
Area in which cable entries, switch operators, windows, receptacles etc may be fitted to be shown. (volountarilly, the location of fittings may be specified)
Method of retaining a non-threaded fitting e.g. a fitting having a spigot joint.

Hole dimensions, location and spacing on face of enclosure where a certified component is to be fitted.

Bearing specifications to enable calculation of “m” and “k” for rotating machines.

Metal type and details (including locations) of earthing and bonding facilities.

Overall dimensions of the enclosure including minimum wall thickness.

Weld type and size.

Minimum thickness of window, material and method of mounting.

Normally, layout and heat dissipation of internal components showing location and approximate dimensions of each component, including clearances between components and the nearest sidewall. The purpose is to control:
- Location of sources of heat, for temperature classification purposes, for temperature withstand of plastic parts, window cement, other potting materials, cable entries, etc., and for confirming the local ambient for items such as IS safety barriers
- Dimensions relevant to pressure piling effects

Pressure piling: If a flammable mixture is compressed before ignition, the resulting explosion pressure will be significantly higher than when the same mixture is ignited at normal atmospheric pressure.

Where the certificate is to cover variations in content: sufficient detail of the range so that the design limits for each variant are absolutely clear and all versions must to be fully specified.

The accredited testing lab can then select the worst case arrangement(s) for test purposes.

Surface roughness of flamepaths.
For cemented joints: specification of cement, manufacturer’s data sheet, and the shortest distance through the cemented joint.

Washer type (if used) and washer thickness.

Specification and data sheet for setting compounds used in stopping boxes etcetra.
Full specification for sintered metal components forming part of an enclosure or combustible sensor: material, max bubble pore size, minimum density, dimensions etcetra. Construction drawings for combustible sensors materials (maximum bubble test pore size)
Comparative Tracking Index (CTI) for insulating material subject to electrical stress if the type of protection depends on it, e.g. through going bushings.

Electrical stress: without insulation protection, the voltage passes through the conductor and moves throughout the insulation and goes very erratically and effectively to the ground, which causes hot spots and ultimately cable failure.

Gross and net internal volumes if not evident from general dimensions.
Installation precautions for cells and batteries.
Length and diameters for press-fitted or interference fitted part.

Press-fitted or interference fitted part: It is a type of engineering fitting where the paired components are held tightly against each other by friction.

Identification of grease if applied to the joints and specification data sheet with details on ageing process, solvent evaporation, corrosion, flash point.

Aging process: Aging process is used after other heat treatment processes to adjust the properties of the alloy, which leads to increased strength and durability. The aging process occurs naturally over time, but the use of heat accelerates this process. The aging process is usually done in the oven.

Thickness of electroplating on flamepaths.
Details of safety devices for battery protection against excessive temperature, reverse polarity and exceeding the manufacturer charging specification.
Details and location of any internal thermal protective devices.
Density of breathing devices
Minimum thickness of breathing devices

Special requirements for Exe equipment

Minimum creepage and minimum clearance distances.

Comparative Tracking Index (CTI) including data sheet for the material to substantiate the repeatability of the characteristic.

Type and details of terminals used in junction boxes (e.g. type, material, rating).

Insulation on windings specified by manufacturer’s data sheet, all relevant processes – e.g. for impregnation.

Details of all insulating materials and their data sheets where not defined by reference to an EN standard.

Drawings for motors that identify the radial airgap and indicate how it is achieved during

For example, this information may be provided by confirming that the gap is set and measured during manufacture, or by providing information to show how a gap is defined but not measured, taking into account various tolerances and Eccentricy or deviations from the circuit which may help to make the equipment in operation are obtained.

manufacture. For example, this may be by confirming that the gap is set and measured during manufacture, or by providing information to clearly show how a defined, but non-measurable gap, is achieved by considering the various tolerances and eccentricities that may contribute to the actual build.

Warning label drawings including material and method of marking and fixing.

Specification of soft starters/frequency converters intended for use with motors.

Soft starter: A soft starter is a device that is used with AC electric motors to temporarily reduce the load and torque in the power transmission system and increase the electric current of the motor during start-up and reduces the mechanical stress of the motor and shaft as well as electrodynamic pressures. It is connected to the power cables and the power distribution network and increases the life of the system.

Details of temperature limiting devices: identification and rating, specification of supplying voltage, mounting, wiring, insulation and termination.

Details of associated external protection devices (e.g. certified overload protection device for a motor) if a dedicated device is required, otherwise appropriate detail to allow a generic protection device to be correctly selected.

Details of electrical components of luminaires including lamps, lampholders, ballasts, terminals, starting circuits, fuses and batteries.

For rotating Machines: details of rotor bars as to method of location and achieving tightness within the slots, and the method of fixing/connection to shorting rings.

Internal as well as external fan clearances and method of achieving them.

Data for gaskets including material, dimensions, placement and security.

Details of anti-condensation heaters: identification and rating, specification of supplying voltage, mounting, wiring, insulation and termination.

Anti-condensation heaters: designed to maintain the temperature of an electrical enclosure and used to eliminate the water vapor inside the enclosures, and also by keeping the internal temperature of the electrical enclosures higher than the freezing temperature, protection They provide protection against freezing.

The minimum conductor dimension of wires used for winding

Specification for rolling bearing minimum radial or axial clearance between stationary and rotating parts for non-rubbing seals, specification of clearances for sleeve bearings.

Potential air gap sparking risk assessment for cage rotor ignition risk factors.

Potential stator winding discharge risk assessment for motors.

Ex equipment with increased safety (Exi)

For intrinsically safe apparatus: full schematics/circuit diagrams including component reference designations to correlate with parts list supplied.

For associated apparatus: schematics/circuit diagrams, including all component reference designations to correlate with the listing of safety relevant components necessary for intrinsic safety, including sufficient detail to verify the measures used to ensure intrinsic safety of the associated apparatus.

Note: In some cases it may be possible to reduce the amount of detailed information for circuits which are encapsulated. Advice should be sought from the relevant Certification Body.

Full listing of parts on which intrinsic safety depends, including for each component either:
- one or more specific manufacturer(s) and part number or range of part numbers, or
- sufficient specification required to maintain intrinsic safety.

Information sufficient to demonstrate that the ratings of the components on which the intrinsic safety depends are in accordance with clause 7 of EN 60079-11 (e.g. technical data,spreadsheets, specifications, calculations and temperature modes of the components on which the intrinsic safety depends).

Note: Maximum flexibility in manufacturing is achieved by minimising the details provided. For example, instead of providing nominal values and tolerance for resistors, it may be possible to supply only a minimum resistance (which is applicable having taken tolerance into account). For components on which intrinsic safety depends, sufficient information to demonstrate compliance with clause 7 of EN 60079-11 is required. For other non- energy storage components, it may be possible to provide no more than the component type and package.

Clear identification on the schematic drawings, for example by a dotted line, of the boundary between IS and non-IS circuit(s) in an associated apparatus requiring segregation.

Specific marking on the circuit diagram or in the parts list of electrical components on which the intrinsic safety depends.

A note explaining any identification symbol used

for example, “These components are safety components and may not be altered from the defined specification without approval of the Certification Body”) on the circuit diagram or on a separate document used as work instructions in production.

Correctly scaled PCB layout drawings or electronic Gerber (or alternative) files including:
- PCB material and thickness;
- distance between layers (if applicable);
- conductor material and thickness;
- minimum Comparative Tracking Index (CTI) (if applicable);

Note: EN 60079-11 does not require the minimum Comparative Tracking Index (CTI) to be specified if the circuitry is rated for voltages of 10 V or less or if the circuitry (together with the PCB) is encapsulated in a casting compound or completely coated.

Casting: The process of pouring a liquid composition into the mold with the normal pressure of the environment.

Compound: Any heat-hardening or thermosetting material, thermoplastic, epoxy or elastomeric resin with or without fillers or additives, in solid state.

All safety distances in relation to the tracks on the wiring board.

All safety distances between components, terminals, or within safety components.

Minimum cross-sectional area, conductor type and insulation thickness of wires.

Minimum track width for temperature classification for IS apparatus and for tracks considered as infallible against open circuit failure.

Correctly scaled general mechanical arrangement drawings including details of any enclosure, and where relevant to intrinsic safety, the materials and surfaces used.

General arrangement drawings show how the components fit together to form the whole equipment. Depending on the complexity of the structure of the explosion-proof equipment, the overall layout plans may include several different plans.

An interconnection diagram for equipment that includes internal interconnections, including identification of the boundaries where more than one protection concept is used within the equipment.

Assembly manufacturing drawings for custom components including specification of materials where relevant to safety and separation distances when required for safety.

Details of application and properties of insulating varnishes (conformal coatings).

To specify the separation distances, if Tables 8 and 9 of the IEC 60079-11:2023 standard are used, specifying them on the drawings or technical documents in which they are used and the statement of the degree of environmental pollution and overvoltage category or Overvoltage category.

Details of any encapsulation materials used including generic name and type.

Statement of those entity parameters on which assessment is to be based. This usually includes one or more of Um, Ui, Ii, Pi etc. but may include limits to other parameters such as LO/R, LO, CO etc. which are determined during the course of the assessment, if they are a requirement of the product specification.

A statement of any special requirements for installation, live maintenance and use as supplied in the instructions.

Note: a control drawing is a recommended form of consolidating connection information and special requirements for installation and use.

Details of any special conditions which are assumed in determining the type of protection; for example that the voltage is to be supplied from a protective transformer or through a diode safety barrier.

Devices with protection for Encapsulation “Exm”

Details of the encapsulation compound(s)

Defitition of Compound: Any heat-hardening or thermosetting material, thermoplastic, epoxy or elastomeric resin with or without fillers or additives, in solid state.

Note: according to point No.6 of above general requirements for tchnical file preparation, Materials of parts relevant to the type of protection should be unambiguously identified. Where possible, this should be by reference to a material grade given in an IEC or EN standard. Where no relevant IEC or EN standard is available, reference may be made to other nationally, regionally or industry recognised standards. Where no standard is available, or where the standard does not control all relevant requirements, the material manufacturer’s data sheet should be submitted.

Description of the production process of filling the equipment with compound, preferably a quality system work instruction or manufacturer’s recommended instruction.

A drawing showing the minimum distance from components within the encapsulation to the nearest surface of the compound. Dimensions showing the compound thickness between all components containing free spaces.

Maximum electrical input parameters specification.

Circuit diagram and physical layout of circuit boards.

Detail and location of any included protective device, e.g. thermal fuse.

Specification of any required external protective device, e.g. fuse.

Protection by Pressurisation “Exp”

General arrangement of purged enclosure with dimensions including material and method of construction, and statement of gross free volume.

A schematic diagram showing the control circuit for purging and pressurisation, normal operation and shut down. Definition of settings and limits and a statement on safety integrity that is compatible with the level of protection being claimed. Use of EN 61508 series is a suitable option.

Diagrams showing the purge and pressurisation ducting or pipework, components, pressure gauges etcetra.

Details of purging gas.

Statement of maximum, minimum and normal operating pressure.

Details of intake and outlet ducting and manifold distribution system.

Indicate details of certified components/equipment.

Detail windows and all other devices fitted on the enclosure boundary e.g. pushbuttons, indicator lamps, etcetra.

Layout of internal components and their thermal dissipation.

Details of how venting of any large enclosure volume is achieved.

Statement of presence of any cells/batteries and precautions taken.

Equipment with Non-sparking protection “Exn”

General arrangement of enclosure giving principal dimensions.

Ingress protection of sealing methods and seal details.

Details of connection facilities, showing how the conductor is secured to comply with the standard.

Details of connection methods for jointing internal wiring by either describing the construction features necessary for maintaining conformity, or the manufacturer and part number of the connector.

All Clearances and Creepage distances, showing actual paths. For connection facilities, this should take into account all potential positions of the moving parts, e.g. with terminals fully open and fully tightened.

Fixing of rotor bars to rotor and the method of connection to shorting rings, for rotating machines.

Specification of any required external protective device, e.g. fuse.

Details of frequency converters and their parameters for the motor to operate within its temperature class. As a minimum, the type of converter, the minimum set up information such as minimum carrier frequency and the acceptable speed ranges.

Details/specification of fuses if applicable.

Facilities (if applicable) to ensure plug and socket cannot vibrate loose.

Specification of lampholder, starter and starter holder types for luminaires.

Details of any warning labels.

Enclosed break devices and non-incendive components with specification of free internal volume of components.

Thermal stability parameters of any poured seals or encapsulating materials.

Specification of any free volume for sealed or encapsulated devices.

Details of temperature limiting and/or regulating devices (e.g. type of device such as thermistor or thermostat. In the case of the thermostat, how the contacts are protected, e.g. by a sealed construction or by an enclosed-break construction, and in either case the limiting temperature): identification and rating, specification of supplying voltage, mounting, wiring,insulation and termination

Details of associated external protection devices (e.g. temperature control on heater).

Specification for rolling bearing minimum radial or axial clearance between stationary and rotating parts for non-rubbing seals. If relevant, specification of clearances for sleeve bearings

Potential air gap sparking risk assessment for cage rotor ignition risk factors.

Potential stator winding discharge risk assessment for motors.

Details of anti-condensation heaters: identification and rating, specification of supplying voltage, mounting, wiring, insulation and termination

Dust protection by enclosure “Ext”

General arrangement of enclosure / equipment.
Sealing method/arrangement/shaft seals/bellows.
Internal electrical equipment, general arrangement layout, power rating.

Layout and heat dissipation of internal components showing location and approximate dimensions of each component, including clearances between components and the nearest sidewall. The purpose is to control location of sources of heat, for temperature classification purposes, for temperature withstand of plastic parts, window cement, other potting materials, cable entries, etc., and for confirming the local ambient temperature.

Where the certificate is to cover variations in content, sufficient detail of the range so that the design limits for each variant are clear.

Construction details of sealing, depending on the EPL.
Hole spacing for fasteners.

Fastener specifications including type of fastener, material, thread size and pitch.

If required for joints: sizes, type, thread engagement, flange, spigot.
Details of warning labels.
Drawing that show all holes into enclosure, threaded entries, thread length.
Details of materials of enclosure, window material, thickness, sealing.

Equipment protected by Oil-immersion “Exo”

A general arrangement drawing showing enclosure details, including:

Bolt/screw hole spacing.
Enclosure material specification.

Pressure relief device and its release pressure for sealed devices.
Breathing device and drying agent details if enclosure is not sealed. A maintenance specification for the drying agent.

Means by which external and internal fasteners are secured from accidental loosening as well as details for securing devices such as liquid level indicators.

Fill and drain plugs.

Liquid level indicating devices with markings to show the minimum and maximum levels for

the protective liquid for the temperature range for which the liquid will be subject to in service. Details of the level to which electrical equipment is filled.

Evidence demonstrating that transparent parts will retain their mechanical strength and optical properties when in contact with the protective liquid.

The dipstick and its sealing and guide hole details for non-sealed apparatus.

Details of warning label for replacement of dipstick after use.

Name, description, flashpoint etc. of protective liquid.

Specification of protective liquid including name, description, flashpoint, etcetra.

Method of sealing and securing devices for draining the liquid.

Oil expansion facility for non-sealed enclosures.

Details of means of interrupting the supply in the event that an internal fault produces evolution of gas.

Details of electrical terminations and explosion protection technique applied.

Equipment protected by Powder filling “q”

General arrangement showing enclosure details, methods of securing the enclosure (e.g.cementing/riveting/welding cementing of screws/lead-seal safety-wiring of screws), material specification and thickness.

The specification of the particle material, the size range of the particles, as well as the filling process and the measures taken to ensure proper filling.

Statement of free volume of any electrical devices or components that have a cavity not filled with powder (e.g. relays).

Total capacitance with tolerance(s) of all capacitors and working voltage of each capacitor.

Cable entry and/or bushing sealing.

Sealing to achieve degree of protection.

Maximum width of gap.

PCB trackwork and component layouts (scaled), PCB coatings, component list with component values and tolerances, minimum distance through filling compound between electrically conductive materials and (i) insulated components and (ii) inner surface of enclosure.

Fuse current rating In.

Thermal protection device.

Protection for Non- electrical equipment "Exh" according to ISO 80079-36 and ISO 80079-37

Because of the variety of methods of reducing ignition risks for non-electrical equipment, it will only be possible to determine the details required on documents after completion of the Ignition Hazard Assessment (IHA).

The required details are specified in Annexes A14, A15, A16 and A17 of ISO/IEC 80079-34:2018 or EN ISO/IEC 80079-34:2020 and are as follows:

Non-metallic parts

material characteristics;
finish;
surface resistance;
surface area of non-conductive parts;
limitation of thickness;
measures for charge bonding (earthed frames).

Casing and external parts

material of the casing and content of light metals;
protection of removable parts against unintentional or inadvertent removal;
materials used for cementing including a visual inspection after curing

Earthing and equipotential bonding of conductive parts

earthing terminal;
effective connection of conductive parts;
bonding cables

Light transmitting parts

material;
integrity
guards and protective covers

Ingress protection (IP)

weld continuity;
fitting of gaskets and seals;
continuity of moulded grooves and tongues;
cement curing.

ATEX guides

ATEX technical file

ATEX guides

Guideline for preparation product technical file for ATEX certification

I-O-20 , VER 00

This guide is based on the following references:

ATEX directive, annex III or module B, part C of paragraph 3

IECEx OD 17: Guide for explosion-proof manufacturers and laboratories to prepare drawings and technical documents for explosion-proof equipment.

Required documents for ATEX technical file

a unique number shall be assigned to technical file.

list of content of technical file

Company introduction

Company registration documents

Certificates of Quality Management, such as ISO 9001, if any

General description for product type

clear identification and description of subset models of product type, if any

clear pictures of product

part list which have formed the equipment or component

data sheets, drawings/circuit diagram (if epplicable) and other needed information for parts and material which have formed the equipment or component

descriptions and explanations necessary for the understanding of above drawings and schemes and the operation of the product.

Results of design calculations made and examination carried out.

user manual of the Ex product

maintenance instructions of the Ex product

list of fully or partially applied harmonized standards and descriptions of solutions used to meet the essential requirements of ATEX Directive where those standards are not applied .

Report of routine tests which may be performed by the manufacturer.

ATEX Certificates of components, if any

EU Declaration of Conformity

Product Risk Analysis Reports according to ATEX 2014/34/EU - Annex II.

Basic Points

The technical file must show the concept of explosion-proof equipment safety, including what type of protection is used for each part of the equipment structure, and what border lines are included and in which parts of the equipment structure.

The requirements stated in this manual do not replace the requirements of the EN 60079 series of standards related to explosion-proof equipment, but clarify and supplement them.

If there are any conflicts between the EU harmonized standards and this guide, the wording in the standard takes precedence.

The drawings and other technical documentation that form the specification of the product used to demonstrate explosion protection conformity are a definitive specification of the product that has been certified.

However, in such cases, to prepare and control the manufacturing drawings, the manufacturer of explosion-proof equipment must have an effective system to control that all the requirements stated in the technical drawings of the explosion-proof file are covered in the manufacturing drawings.

If there is a need to modify the drawings of the explosion-proof equipment after the issuance of the ATEX certificate, the details related to the modification or corrections made on the drawings could be provided only by referring to the initial certificate issued and the relevant notified body.

Changes to the technical file drawings and documents are implemented only after the certification body has issued a revision to the certificate to incorporate the new drawings and documents.

according to definition provided by EN ISO/IEC 80079-34:2020,

schedule drawing: drawing or document listed in the certificate or test report, therefore the drawings exist in ATEX technical file are named schedule drawings.

related drawing: drawing or document not listed in the certificate but linked to the schedule drawing, and used for example, for detailed manufacture or purchase of component parts.

In 7.5.3 of EN ISO/IEC 80079-34:2020, concerning control of manufacturing documents, both the drawings and documentation referred to in this guideline, are referred to as "Schedule Drawings".

The language of all drawings and technical documents that make up the technical file must be English or Italian only.

The technical file should be set in the form of non-paper version in the form of conventional format files.

For example, material specified “epoxy glass resin with a CTI of greater than 175” would require proof of compliance with the CTI limit for each purchased batch. This can be achieved, for example, by an epoxy manufacturer’s declaration or by a third party.

General requirements for ATEX technical file preparation

Among all essential health and safety requirements (EHSR's) indicated in annex II of ATEX directive, the risk assessment table shall be set only for those risk which have been indicated by the relevant clause of the relevant harmonized standard in annex ZZ of the relevant harmonized standard.

in fact, annex ZZ of each ATEX harmonized standard, includes relation between requirements of the standard and EHSR's of annex II of ATEX directive.

All drawings should be identified by: drawing number, revision number, date of revision, title and name of the design authority in whose drawing record system the drawing is recorded (with relationship to the manufacturer if different).

All measurements given on drawings should be expressed in SI units.

All dimensions relevant to compliance with the standards should be toleranced unless not required by a specific standard.

For earthing and bonding connections, the connecting method, the construction, parts,dimensions and material specifications including corrosion protection, should be identified.

Note: Bonding is used to reduce the risk of electric shock to anyone who may touch two separate metal parts if there is a fault somewhere in the source of the electrical installation.

For rotating machines, the drawing or document should identify all possible points where clearance of rotating parts is relevant, together with information to determine how the minimum clearances required by the standards are achieved on assembly.

Where applicable, details of mounting and guarding should be provided.

Where ingress protection is relevant, materials of gaskets (and ‘O’ rings) and the method of ensuring or controlling position, adhesion, and compression of the gaskets in service should be clear. Dimensions of gaskets and related features should be specified.

Correctly scaled and dimensioned general arrangement and enclosure drawings including layout should be supplied.

Note: General arrangement drawings show how the components fit together to form the whole equipment. Depending on the complexity of the structure of the explosion-proof equipment, the overall layout plans may include several different plans.

A circuit diagram (single line) including details of external connections should be provided.

Ratings of all protection devices should be specified.

Rating: The maximum amount of current and the maximum amount of voltage that any special electrical equipment can withstand, when it works at its maximum capacity.

Technical description of the equipment and its specification should be provided.

Identification of bearings including conditions of use should be supplied. Bearing data sheets should be provided detailing the working temperatures for the bearings.

Components which have ATEX component certificates should be identified in the parts list with their ATEX certificate number, or referenced from additional separate documents.

A description of all intended routine tests should be included in the drawings or documentation.

Note: Some details (such as pass criteria) may not be known at the time of submission for certification.

The documentation should specify the environmental conditions for which the equipment is suitable. For example IP rating where applicable.

A document must be provided that defines the parts of the user instructions of the explosion-proof equipment that guarantee safe operation related to explosion protection, including the specific conditions of safe use and the requirements of EN IEC 60079-0:2018, especially clause 1.30.

Note: This document can be the user instructions themselves provided there is sufficient identification of the safety related instructions to enable verification of any changes, for example by placing them in an Annex.

Enclosures with opening delay time marking based on charges of enclosed capacitors should have schematics/circuit diagrams provided which include component reference designations to correlate with the parts list. The parts list should define the voltage and capacitances of such capacitors.

Where cells or batteries are included in the equipment, the following should be specified:

manufacturer's name and part number

mounting, connection and orientation details

data sheet from the manufacturer of the cell

identification of the published IEC or EN cell standards to which the cell complies (this is normally already identified on the cell data sheet)

details of the construction where cells are combined into a pack

details of any required marking on the enclosure or battery pack relating to user replacement.

Batteries supplied with existing ATEX certificates require the certificate number, but do not require details of the internals of the battery.

For radio, optical radiating including laser, and ultrasonic equipment, identification and details on threshold power and thermal initiation time and frequency.

Cable/conduit entry points are to be identified and their locations specified.

Special requirements for Exd enclosures

Length of flamepath and maximum flamepath gap for each constructional gap/joint with maximum constructional tolerance. Constructional length of flame path ‘L’ & ‘l’.