Europe / IEC
In Europe and IEC countries, 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 |
ATEX
CAT |
EN / IEC |
Permitted
Zone |
Typical
Applications/Comments |
| Zone
0 |
Zone
1 |
Zone
2 |
| General Requirements |
|
|
60079-0 |
|
|
|
Basic electrical & mechanical requirements |
| Oil Immersion
|
o |
2 |
60079-6 |
|
Yes |
Yes |
Transformers, starting resistors |
| Pressurized |
p |
2 |
60079-2 |
|
Yes |
Yes |
Switchgear and control cabinets, analyzers,
large motors |
| Powder filled
|
q |
2 |
60079-5 |
|
Yes |
Yes |
Transformers, capacitors, heating conductor
terminals |
| Flameproof |
d |
2 |
60079-1 |
|
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 |
60079-11 |
Yes |
Yes |
Yes |
Safe with 2 faults. Level measurement
|
| Intrinsic safety
ib |
ib |
2 |
60079-11 |
|
Yes |
Yes |
Safe with 1 fault. Instrumentation and
communication technology, sensors, actuators |
| Encapsulated |
m |
2 |
60079-18 |
|
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 EN 60079-0 |
| 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 |
|
| |
l l l l l l l l l © Expo Technologies 2004 |
