Andrew Wireless Innovations Group BCEL-FAST819 User Manual
MN021-01
Page 27 of 28
25. Appendix G - Classifying hazardous areas
Hazardous Area
A hazardous area is defined as: "An area in which a flammable substance in the form of gas or
vapour or dust, when mixed with air, is present in such proportions that it can explode when in
contact with an ignition source.
Area Classification
Hazardous areas are classified with respect to the potential danger or an explosion, and the
areas are divided into zones:
CONDITIONS
CE Code
EC
Continuously Hazardous
Division 1
Zone 0 - An area in which an explosive gas/air mixture is
continuously present or is present for long periods.
continuously present or is present for long periods.
Periodically Hazardous
Division 1
Zone 1 - An area in which an explosive gas/air mixture is
likely to occur under normal operating conditions.
likely to occur under normal operating conditions.
Occasionally Hazardous
Division 2
Zone 2 - An area in which an explosive gas/air mixture is
unlikely to occur, but if it occurs, it will be of short duration.
unlikely to occur, but if it occurs, it will be of short duration.
Gases & vapour classification
Gases are grouped together basing on the amount of energy required to ignite the most
explosive mixture of the gases with air. Equipment is classified into groups according to the
gases and vapours for which it is suitable and must be selected with a grouping, which covers
the gases and vapours which, will be present where it is to be installed:
Group
Representative Gas
Ignition Energy
I
IIA
IIB
IIC
IIB
IIC
Methane
Propane
Ethylene
Hydrogen
320 Microjoules
300 Microjoules
160 Microjoules
300 Microjoules
160 Microjoules
40 Microjoules
GAS
CE CODE
IEC
Acetylene
Class I, Group A Group IIC
Hydrogen, Butadiene, Ethylene Oxide, Propylene Oxide, or Acrolein
Class I, Group B Group IIC
Ethylene, Cyclopropane, Ethyl Ether, or Ethylene
Class I, Group C Group IIB
Propane, Acetone, Alcohol, Ammonia, Benzine, Benzol, Butane,
Gasoline, Hexane, Laquer Solvent vapours, Naptha, Natural Gas
Gasoline, Hexane, Laquer Solvent vapours, Naptha, Natural Gas
Class I, Group D Group IIA
Coal Mines
Gaseous Mines Group 1
Combustible Dusts
Class II
Ignitable Fibres or Flying
Class III
To ensure the suitability of electrical equipment for use in hazardous areas, the equipment is
certified and uses various techniques known as Methods of Protection. As not all Methods of
Protection are suitable for all hazardous areas, care must be taken to select equipment, which
is suitable for use in the Zone in which it is installed.
certified and uses various techniques known as Methods of Protection. As not all Methods of
Protection are suitable for all hazardous areas, care must be taken to select equipment, which
is suitable for use in the Zone in which it is installed.
Zone 0
Zone 1
Zone 2
Ex ia - Intrinsic safety
Ex s - Special protection if
specifically certified for Zone 0
Method suitable for Zone 0
Ex ib - Intrinsic Safety
Ex d - Flameproof enclosure
Ex e - Increased safety
Ex m - Encapsulation
Ex s - Special protection
Method suitable for Zone 0 or l
Ex N - Type of protection N
Ex o - Oil immersion*
Ex q - Powder filling*
Ex p - Pressurised or purging
* may be suitable for Zone 1