Rockwell Automation Low-Voltage Switchgear and Controlgear - Manual (Page 70)

Classification of equipment acc. to IEC/EN Categories of zones exposed to the risk of ignition
Equipment group
(application area)
Combusti-
ble
sub-
stances
Equipment
category
Zones
IEC/EN
Temporary behaviour of combustible
substances in zones exposed to the
risk of explosion
M1
I
Mines
Methane,
Dusts
M2 oder M1
Underground parts of
mines and suface
installations of mines
1G Zone 0
Permanently, long-term or frequently
present
2G
or 1G
Zone 1 Occasionally present
Gases,
vapours
3G
or 2G/1G
Zone 2
Low probability of presence or rare
occurence or short-term
1D Zone 20
Permanently, long-term or frequently
present
2D or 1D Zone 21 Occasionally present
II
Other areas with
combustible
atmospheres
Dusts
3D
or 2/1D
Zone 22
Low probability of presence or rare
occurence or short-term
Explanation of equipment categories:
M1 Continued service in case of presence of combustible atmosphere must be guaranteed
M2 It must be possible to switch-off the equipment in case of presence of combustible atmosphere
1G/D very high safety = Equipment safety must be maintained even in case of rare malfunctions,
e.g. at occurrence of two independent failures.
2G/D high safety = Equipment safety must be maintained in case of frequently expected malfunctions,
e.g. in case of failure of one component.
3G/D safe under normal service conditions = Equipment safety guaranteed under normal service conditions
Tab. 2.4-2
Classification of electrical equipment according to the equipment-group (for example II) and equipment-
category (for example 3 G for Zone 2) and classification by zones
Standard
Ignition protection Principle of protection Zone
EN / IEC
General requirements
EN 50014
IEC 60079-0
Installation
EN 60079-14
IEC 60079-14
Flameproof enclosures d
Avoid the transfer of an
explosion to the outside
1 / 2
EN 50018
IEC 60079-1
Increased safety e
Avoid sparks and ignition
temperatures
1 / 2
EN 50019
IEC 60079-7
Intrinsic safety i
Limitation of the energy of
sparks and of temperatures 0 / 1 /
2
EN 50020/39
IEC 60079-11
Pressurized enclosures p
Keep Ex-atmosphere away
from source of ignition
1 / 2
EN 50016
IEC 60079-2
Encapsulation m
Keep Ex-atmosphere away
from source of ignition
1 / 2
EN 50028
IEC 60079-18
Oil immersion o
Keep Ex-atmosphere away
from source of ignition
1 / 2
EN 50015
IEC 60079-6
Powder filling q
Avoid the transfer of an
explosion to the outside
1 / 2
EN 50017
IEC 60079-5
Type of protection „n“ n
Various principles of protection
for zone 2
2
EN 50021
IEC 60079-15
Protection by enclosure IP
Keep Ex-atmosphere away
from source of ignition 20 / 21 /
22
EN 50281-1-1
IEC 61241-1
Tab. 2.4-3
Ignition protection types and corresponding EN and IEC standards
The identification of ignition protection types of electrical equipment usable e.g. for Increased
Safety “e”, Explosion Group IIC and Temperature Class T6 is different according to EN and IEC
as follows (see also Section
2.4.7.5 ):
LVSAM-WP001A-EN-P - April 2009 2-42