What is an ATEX zone? Which product to choose?

Published on : 2023-10-04 - Categories : Events

Wondering what ATEX zones are? Wondering which products you can buy that comply with these standards?

Don't move, you've come to the right place.

ATEX zones, definitions :

Not all explosion-proof equipment can be built to the maximum requirements, and therefore cannot be installed in any environment where there is a risk of explosion.

European standards distinguish three main groups of equipment:

Group I: electrical equipment intended for installation in mines liable to contain firedamp.

Group II: electrical equipment for all other areas with potential gas explosion hazards.

Group III: electrical equipment for locations with explosive dust atmospheres, other than firedamp mines.

Group II and III equipment are subdivided into gas and dust explosion groups respectively.

Gases, vapors and dusts are classified into explosion groups.

These groups are defined according to the ignition and explosion capacity of an explosive mixture. Dusts are classified in explosion groups according to their size and electrical conductivity. All electrical equipment must indicate for which group (A, B or C) it has been designed. It goes without saying that equipment marked IIC or IIIC meets the most stringent requirements, and is therefore also suitable for gases and dusts in groups A and B.

GROUP FOR ATEX EQUIPMENT

You will also find a temperature classification for Group II equipment:

The ignition temperature varies according to the nature and characteristics of the gases present. The temperature of the outer surface of explosion-proof equipment cannot be such that it becomes a source of self-ignition for the surrounding environment. For this reason, Group II electrical equipment is subdivided into the following temperature classes, based on maximum surface temperature:

Group II ATEX electrical equipment is subdivided into the following temperature classes.

Once these elements have been identified, you can move on to defining ATEX zones:

Zone classification

Each space or environment where there is a risk of gas explosion is divided into zones (0, 1 or 2), according to the risk posed by any explosive mixture in that space.

Now that you know what ATEX zones are, you can decipher the level of protection for your equipment.

Equipment protection levels

Group I: mines

EPL Ma: Devices designed for installation in coal mines, which have a very high level of protection and which, in the event of exceptional malfunction of the device, will continue to operate in an explosive environment.
EPL Mb: Equipment designed for installation in a coal mine, which has a very high level of protection and will be disconnected from the power supply in the event of an explosion.

Group II: gases

EPL Ga: Devices intended for installation in an explosive gas environment, which offer a high level of protection and which, in the event of exceptional malfunction of the device, guarantee this level of safety.
EPL Gb: Devices intended for installation in explosive gas environments, which offer a high level of protection and which, in the event of frequent malfunctions or faulty operation of the device, guarantee this level of safety.
EPL Gc: Devices intended for installation in an explosive gas environment, which offer a normal level of protection and which, in normal operation, guarantee this level of safety.

Group III: dust

EPL Da: Devices intended for installation in an environment containing explosive dust, offering a very high level of protection and guaranteeing this level of safety in the event of exceptional device malfunction.
EPL Db: Equipment designed for installation in environments containing explosive dust, offering a high level of protection and guaranteeing this level of safety in the event of malfunctions.
EPL Dc: Devices intended for installation in an environment containing explosive dust, which offer a normal level of protection and which, in normal operation, guarantee this level of safety.

Relationships between EPLs and ATEX zones