ATEX & IECEx Equipment

The ATEX Directive and IECEx system

When electronic or electrical equipment of any type is intended for use in a hazardous area within Europe, the equipment must be ATEX certified as required by the EU directive 2014/34/EU (Previously 94/9/EC.) This directive is more commonly known as the ATEX directive (from the French: ATmospheres EXplosives).

Outside of the European Union the IECEx certification system is now becoming commonplace and is accepted alongside national certification systems. In North America products must be listed by a body like UL, FM or CSA as suitable for use in hazardous atmospheres. Please note that while the ATEX and IECEX certification system are similar, the North American approach is different, see area classification below.

Classification of an area:

Hazardous areas exist where a potentially explosive mix of air and flammable gasses or air and dust or air, dust and gases may occur. It is the duty of the facility owner to identify and define the hazardous areas.

Hazardous areas are divided into Zones (European and IECEx method) or Divisions (North American method) according to the likelihood of a potentially explosive atmosphere being present.

 

European & IECEX classification

Definition of zone or division

North American Classification

Zone 0 (gases)

Zone 20 (dusts)

An area in which an explosive mixture is continuously present or present for long periods

Class I Division 1 (gases)

Class II Division 1 (dusts)

Zone 1 (gases)

Zone 21 (dusts)

An area in which an explosive mixture is likely to occur in normal operation

Class I Division 1 (gases)

Class II Division 1 (dusts)

Zone 2 (gases)

Zone 22 (dusts)

An area in which an explosive mixture is not likely to occur in normal operation and if it occurs it will exist

Class I Division 2 (gases)

Class II Division 2 (dusts)

 

Classification of equipment:

The ATEX directive classifies equipment into groups and categories which are defined by the marking on the equipment as detail below. The classification and marking of the equipment allows the user to determine whether or not it is suitable for the area it is to be installed in.

 

Product marking:

The ATEX directive requires the product to be marked with the CE mark, the "EX" mark and the equipment coding as per table below.

 

Heading

Mark

Use

Explosion proof 

 

in accordance with the ATEX directive  

Equipment Group

I

II

For use in underground mines

For use in all other places

Category

1

 

 

 

 

2

 

 

 

 

 

3

Equipment that is intended for use in areas where an explosive atmosphere is present continuously, for long periods or frequently

 

Equipment that is intended for use in areas where an explosive atmosphere is likely to occur in normal operation and must ensure a high level of protection.

 

Equipment that is intended for use in areas where an explosive atmosphere is unlikely to occur in normal operation and must ensure a normal level of protection.

Gas/Dust

G

 

 

D

 

Equipment certified for use in flammable gases

 

Equipment certified for use where dust is present in the atmosphere

Type of Protection*

 

ia

 

e

Flameproof

 

Intrinsically safe

 

Increased safety

Gas Group

I

II

Mines

Surface above ground industries

Gas Sub Group

A

 

B

 

C

 

Less easily ignited gases e.g. propane

 

Easily ignited gases e.g ethylene

 

Most easily ignited e.g. acetylene or hydrogen

Temperature Classification Hazardous area apparatus is classified according to the maximum surface temperature produced under fault conditions at an ambient temperature of 40°C, or as otherwise specified. The standard classifications are as shown

T1

T2

T3

T4

T5

T6

450ºC

300ºC

200ºC

135ºC

100ºC

85ºC

 

* There are 8 methods of protection, for simplicity we have listed the 3 most commonly used