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General information
According to 94/9/EC, a device that is to be used in an environment at risk of explosion may only be
brought into the market if it satisfies the standards specified in the norm.
Compared with the previous directives, it must be noted that the specification refers not only to electrical
but also to mechanical equipment (e.g. cylinders).
Devices are divided into categories and groups to accurately define the conditions of use. This definition
is marked on the device and may appear as follows:
Device group
There are 2 groups of devices.
Devices of Group I, Category M are for use in underground mines and their above ground equipment, which are
at risk from firedamp and/or inflammable dusts. (This is not given further coverage in this document).
All other areas at risk of explosion are combined in Device Group II.
Identifier
EEx defines that this is an electrical device.
Ignition protection class
This defines which measures are used to ensure explosion protection.
The following ignition protection classes are used by AIRTEC:
m = Encapsulation, ia = Intrinsic safety, c = Safe by design
Other ignition protection classes are defined in EN 50014: 1997. The abbreviations are currently under review
discussion.
It should be noted that devices in ignition protection class ia may only be supplied from circuits that are certified
to be intrinsically safe.
Explosion group
Device group II is sub-divided into Explosion Groups A, B or C.
This classification is dependent on the typical material properties of the gases and vapors that occur.
The hazard level of materials increases from Explosion Group IIA to IIC. The requirements for the devices increase
accordingly. If a device is approved for IIC, it can be used for all other explosion groups. Alternatively, the
chemical formula or the name of the material can be stated here
Temperature class
It must be ensured that the ignition temperature of an inflammable material is not reached during operation. For
this purpose, the maximum surface temperature of a device must be less than the minimum ignition temperature.
For this reason, the maximum surface temperature of equipment for use with inflammable gases, vapors or mists
is specified in temperature classes. For dusty environments, the maximum surface temperature is specified in °C.
Temperature class Maximum permissible surface temperature of the equipment (°C)
T1 450
T2 300
T3 200
T4 135
T5 100
T6 85
ATEX
Category 1
For devices, which guarantee a very high level of safety.
Intended for the case where an atmosphere at risk of explosion is to be expected frequently or continuously.
Devices in this category can also be used in Category 2 and 3.
Inflammable gases, vapors or mists
Zone 0 equivalent to Category 1G
Area in which an atmosphere at risk of explosion as
a mixture of air and inflammable gases, vapors or
mists is continuously or frequently present or present
for long periods.
Inflammable dusts
Zone 20 equivalent to Category 1D
Area in which an atmosphere at risk of explosion in
the form of a cloud of inflammable dust contained in
the air is continuously or frequently present or present
for long periods.
Category 2
For devices, which guarantee a high level of safety.
Intended for the case where an atmosphere at risk of explosion is to be expected.
Devices in this category can also be used in Category 3.
Inflammable gases, vapors or mists
Zone 1 equivalent to Category 2G
Area in which an atmosphere at risk of explosion as
a mixture of air and inflammable gases, vapors or
mists can form occasionally during normal operation
Inflammable dusts
Zone 21 equivalent to Category 2D
Area in which an atmosphere at risk of explosion in
the form of a cloud of inflammable dust contained in
the air can form occasionally during normal operation
Category 3
For devices, which guarantee a normal level of safety.
Intended for the case where an atmosphere at risk of explosion is to be expected rather infrequently and, if so,
for only short periods.
Inflammable gases, vapors or mists
Zone 2 equivalent to Category 3G
Area in which an atmosphere at risk of explosion as
a mixture of air and inflammable gases, vapors or
mists does not normally occur at all or only for short
periods during normal operation
Inflammable dusts
Zone 22 equivalent to Category 3D
Area in which an atmosphere at risk of explosion in
the form of a cloud of inflammable dust contained in
the air does not normally occur at all or only for
short periods during normal operation
The following AIRTEC products are available in explosion-proof design for Device Group II in
accordance with 94/9/EC.
The following list is intended to provide an overview. Attention must be paid to the Operating
Instructions and Declaration of Conformity before commissioning. These can be provided on request.