ATEX Certification Definitions
Typical
IEC EPL
General requirements
Typical
Zone(s)
EN/IEC Standard
0,1,2
60079-0
Is equipment
Ex i concept?
Gb
Ga
Ga
1,2
0,1,2
0,1,2
60079-28
60079-28
60079-28
Protected Optical Radiation
Optical System with Interlock
Intrinsically Safe Optical Radiation
Increased safety
Type ‘n’ (non sparking)
e
nA
Gb
Gc
1,2
2
60079-7
60079-15
No arcs, sparks or hot surfaces.
Enclosure IP54 or better
Flameproof / Explosion-Proof
Type ‘n’ (enclosed break)
d
nC
Gb
Gc
1,2
2
60079-1
60079-15
Contain the explosion, quench the
flame
Quartz/sand filled
q
Gb
1,2
60079-5
Quench the flame
Intrinsic safety
Intrinsic safety
Intrinsic safety
ia
ib
ic
Ga
Gb
Gc
0,1,2
1,2
2
60079-11
60079-11
60079-11
Limit the energy of sparks and
surface temperatures
Pressurised
Pressurised
Pressurised
px
py
pz
Gb
Gb
Gc
1,2
1,2
2
60079-2
60079-2
60079-2
Keep the flammable gas out
Type ‘n’ (sealing & hermetic sealing)
Type ‘n’ (restricted breathing)
nC
nR
Gc
Gc
2
2
60079-15
Keep the flammable gas out
Encapsulation
Encapsulation
Encapsulation
ma
mb
mc
Ga
Gb
Gc
0,1,2
1,2
2
60079-18
60079-18
60079-18
Oil immersion
o
Gb
1,2
Gas
EU Explosive
Atmosphere Symbol
ATEX Coding
Enclosure
Intrinsic safety
Encapsulation
Pressurised
Typical
IEC EPL
ta
tb
tc
ia
ib
ic
ma
mb
mc
Da
Db
Dc
pD
Db
Dc
Typical
Zone(s)
20,21,22
20,21,22
20,21,22
60079-6
21,22,22
Basic concept of protection
60079-31
Standard protection for dusts, rugged
tight enclosure
60079-11
Similar to t, but with some
relaxations if circuit inside is
intrinsically safe
61241-4
Dust
0
20
1
21
2
22
ATEX Certificate No.
----
Equipment Category
Equipment Group
M1
I
1
Very high protection
2
High protection
3
Normal protection
II 2 GD
Surface
No
Is area zoned?
Gas/Dust Groups
Protection Concepts
EN/IEC Standard
General
-
-
0,1,2
20,21,22
13463-1
Low potential energy
Flow restricted enclosure
Flameproof / Explosion-proof
enclosure
fr
d
-
2,22
1,2,21,22
13463-2
13463-3
Relies on tight seals, closely matched
joints and tough enclosures to restrict
the breathing of the enclosure
Constructional safety
c
-
0,1,2
20,21,22
13463-5
Ignition hazards eliminated by good
engineering methods
Control of ignition sources
b
-
0,1,2
20,21,22
13463-6
Control equipment fitted to detect
malfunctions
Pressurisation
p
-
1,2
21,22
60079-2
61241-4
Enclosure is purged and pressurised
to prevent ignition sources from
arising
0,1,2
20,21,22
13463-8
Enclosure uses liquid to prevent contact
with explosive atmosphere
Yes
Yes
Use non-certified
cable glands
Refer to Ex d
cable selector
chart
Ex e concept
Use a barrier
gland
DO NOT OPEN WHEN AN
EXPLOSIVE GAS
ATMOSPHERE IS PRESENT
Yes
Gas Coding
Dust Coding
Mining Coding
Ingress Protection
Gas
Zones
Dust Groups
Zone
Ga
0
Gb
1
Gc
2
Da
20
2nd Numerical
Protection against Liquid
Db
21
Dc
22
Ingress Protection
1st Numerical
Protection against Solid Bodies
0
No protection
0
No protection
Ma
Energised*
1
Objects > 50mm
1
Vertically dripping water
Mb
De-energised*
2
Objects > 12mm
2
Drops of liquid (75° to 90°)
3
Objects > 2.5mm
3
Sprayed water
G = Gas D = Dust M = Mining
*In presence of explosive atmosphere
4
Objects > 1mm
4
Splashed water
5
Dust protected
5
Water jets
6
Heavy seas
Temperature Class
Gas Group
Gas Example
Dust Group
Dust Example
I
Methane (mining only)
IIIA
Combustible flyings
IIA
Propane
IIIB
Non-conductive dust
7
Effects of immersion
IIB
Ethylene
IIIC
Conductive dust
8
Indefinite immersion
IIC
Hydrogen
6Dust-tight
T Class
Maximum Surface
Temperature
T1
450°C
T2
300°C
T3
200°C
T4
135°C
T5
100°C
T6
85°C
Note: For Group I (CENELEC/IEC) applications, electrical
apparatus has fixed temperature imits i.e., 150°C and 450°C
www.extronics.com
Wireless
Vision
Engineering
Tracking
Does this
enclosure
contain an
internal source
of ignition?
1 Dalton Way, Midpoint 18, Middlewich, Cheshire CW10 0HU. United Kingdom
Tel +44 (0)845 277 5000 Fax +44 (0)845 277 4000 Email info@extronics.com
Use certified
cable glands
No
*refer to note 3
No
Is the area of
installation of
Zone 1?
No
Use a suitable
flameproof cable
gland with a
sealing ring.
(Gland with
elastomeric
seals)
No
Definitions
Dust
IEC 60079-10
0
IEC 60079-10
1
21
A place in which an explosive atmosphere is likely to occur in normal
operation occasionally (10≤ x <1000)
2
22
A place in which an explosive atmosphere is not likely to occur in
normal operation, but if it does only occurs for short periods (10>x)
20
Basic concept of protection
Level
*refer to note 2
Brass
Zoning Definitions
IP66
Ambient Range -20°C
to 40°C unless stated
on label
Ex n* or N
concept
Plastic
Is the
volume of
enclosure
greater than
2 dm3?
Yes
Ex e concept
Gland type
Yes
DO NOT OPEN WHILE
ENERGISED
Zone 2
No
Use non-certified
cable glands
Does the
hazardous
gas require IIC
apparatus?
Yes
1 Dalton Way, Midpoint 18, Middlewich, Cheshire CW10 0HU. United Kingdom
Tel +44 (0)845 277 5000 Fax +44 (0)845 277 4000 Email info@extronics.com Web www.extronics.com
Notified Body
Identification No
Yes
Date: 10/02/2015
Serial No.: EXT12345XXX
Ex d IIC T6 Gb
Ex tD IIIC T100°C Db
I M2 Ex d I Mb
-20°C ≤ Ta ≤ + 60°C
Zone 1?
No
Note 1: Non certified cable glands
may be used provided that they
maintain the minimum IP rating
on the certified equipment of IP54
for outdoors and IP20 for indoor
equipment.
Note 2: Non certified cable glands
may be used provided they meet
the requirements of EN60079-0
and EN60079-7 or EN60079-15.
Note 3: Internal sources of ignition
include sparks or equipment
temperatures occurring in normal
operation which can cause ignition.
An enclosure containing terminals
only or an indirect entry enclosure
is considered not to constitute an
internal source of ignition.
Equipment Protection
Level
Equipment Protection Level
Typical
Zone(s)
Gas Groups
Serial No. and Year of
Manufacture
Temperature Class
Is equipment
Ex d concept?
No
*refer to note 1
Protection by pressurisation of
enclosure
Typical
IEC EPL
-
Mining
*In presence of explosive atmosphere
Baseefa 12 ATEX 1234 x
IECEx BAS 12 1234 X
0518
Protection by encapsulation of
incendive parts
Symbol
k
II
De-energised*
Protection Concepts - Non-electrical
Liquid immersion
Energised
M2
iPRODUCT100
Keep the flammable gas out
EN/IEC Standard
60079-18
Product Identification
Keep flammable gas out
Protection Concepts - Dust (electrical)
Symbol
Yes
Basic concept of protection
Op pr
Op sh
Op is
Optical Radiation
START
ATEX Coding
Protection Concepts - Electrical
Symbol
Gland Selection
A place in which an explosive atmosphere is continually present
Ex Environment
Example of hazardous area zones Petrol Station Forecourt
Zone 0
Zone 1
Zone 2
Fuel Storage Tank
Fuel Storage Tank
Radio Frequency Sources
The threshold power of radio frequency (9kHz to 60GHz) for continuous transmissions and for pulsed
transmissions whose pulse durations exceed the thermal initiation time shall not exceed the values shown in
Table 4. Programmable or software control intended for setting by the user shall not be permitted.
For pulsed radar and other transmissions where the pulses are short compared with the thermal initiation
time, the threshold energy values Zth shall not exceed those given in Table 5.
Table 4 from EN 60079-0:2012
Radio Frequency Power Thresholds
Table 5 from EN 60079-0:2012
Radio-frequency Energy Thresholds
Threshold Power
(W)
Thermal Initiation Time
(averaging period)
(µS)
Group I
6.0
200
Group I
1500
Group IIA
6.0
100
Group IIA
950
Group IIB
3.5
80
Group IIB
250
Group IIC
2.0
20
Group IIC
50
Group III
6.0
200
Group III
1500
Equipment for
Equipment for
Threshold Energy Zth
(µJ)