Europe
In Europe, hazardous areas are classified by Zones, Protection Types, Groups and Temperature Classes.
Industrial plants are zoned according to the likelihood of a potentially explosive atmosphere being present
Zone 0 (gases)
Zone 20 (dusts) |
Flammable material present continuously or for long periods (typically 1000 hours or more per year) |
Zone 1 (gases)
Zone 21 (dusts) |
Flammable material present in normal operation (typically between 10 and 1000 hours per year) |
Zone 2 (gases)
Zone 22 (dusts) |
Flammable material present in abnormal conditions only (typically less than 10 hours per year) |
Protection Methods & Standards for Group II Electrical Apparatus for gas atmospheres
| Protection Method |
Code
Ex |
EUROPEAN |
IEC 60079 |
Permitted Zone |
Typical Applications/comments |
C
a
t
e
g
o
r
y |
EN |
Zone 0 |
Zone 1 |
Zone 2 |
| General Equipments |
|
|
50014 |
-0 |
|
|
|
Basic electrical & mechanical requirements |
| Oil Immersion |
o |
2 |
50014 |
-6 |
|
Yes |
Yes |
Transformers, starting resistors |
| Pressurized |
p |
2 |
50016 |
-2 |
|
Yes |
Yes |
Switchgear and control cabinets, analyzers,
large motors |
| Powder filled |
q |
2 |
50017 |
-5 |
|
Yes |
Yes |
Transformers, capacitors, heating conductor terminals |
| Flameproof |
d |
2 |
50018 |
-1 |
|
Yes |
Yes |
Switchgear and controlgear, indicating equipment, transformers, light fittings, motors, heating equipment |
| Increased safety |
e |
2 |
60079 |
-7 |
|
Yes |
Yes |
Terminal & connection boxes |
| Intrinsic safety
ia |
ia |
1 |
50020 |
-11 |
Yes |
Yes |
Yes |
Safe with 2 faults. Level measurement |
| Intrinsic safety ib |
ib |
2 |
50020 |
-11 |
|
Yes |
Yes |
Safe with 1 fault. Instrumentation and communication technology, sensors, actuators |
| Encapsulated |
m |
2 |
50028 |
-18 |
|
Yes |
Yes |
Solenoid valves. low power switchgear, power supplies |
| Type of protection 'n' |
n |
3 |
60079 |
-15 |
|
|
Yes |
Type of protection includes several
methods of ignition protection |
Explosion Groups
| Typical gas hazard |
IEC 60079-0
EUROPEAN EN50014 |
| Acetylene, Hydrogen |
IIC |
| Ethylene |
IIB |
| Propane |
IIA |
Apparatus temperature classification (T class)
| Maximum surface temperature |
IEC/EUROPEAN Temperature class |
| 450°C |
T1 |
| 300°C |
T2 |
| 200°C |
T3 |
| 135°C |
T4 |
| 100°C |
T5 |
| 85°C |
T6 |
|
| |
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