Ex Survey According To Directive 94/9/Ec (Atex) - Siemens MAG 1100 Operating Instructions Manual

SITRANS F M
3.7 Ex survey according
to Directive 94/9/EC
(ATEX)
3. Project guidance
Instrument groups
Applies to instruments used in underground mining
operations, as well as their above ground
I
operations, which can be endangered by mine gas
and/or flammable dusts.
Applies to instruments used in the remaining areas
II which can be endangered by a potentially explosive
atmosphere.
Instrument category
Definition
Instruments of this category are for use in areas
where ignitable atmospheres, caused by a
1G 1D
mixture of air and gasses, vapours or mists, or
(0) (20)
by dust/air mixtures, can exist all of the time or
for long periods of time or else frequently.
Instruments of this category are for use in areas
where ignitable atmospheres caused, by a
2G
2D
(1) mixture of air and gasses, vapours or mists, or
(21)
by dust/air mixtures, can exist some of the time.
Instruments of this category are for use in areas
where ignitable atmospheres, caused by a
mixture of air and gasses, vapours or mists, or
3G
3D
(2) by dust/air mixtures, are not likely to exist.
(22)
However, if they do occur then in all probability,
only seldom or for short periods of time.
(The figures in brackets refer to IEC)
Built according to European norm = E
Explosion protected electrial equipment = Ex
Ex protection labelling in square brackets refers to "Associated electrical equipment"
Type of protection
o Oil encapsulated
p Pressurized apparatus
q Powder filling
d Flameproof enclosure
e Increased safety
Explosion groups
Gases and vapours
(examples)
• Ammonia
• Acetone, aircraft fuel, benzine,
crude oil, diesel oil, ethane, ethanoic
acid, ether, gasolines, heating oil,
hexane, methane, propane
• Ethylene, isoprene, town gas
• Acetylene, carbon disulphide,
hydrogen
Ignition temperature
Maximum surface temperature
450°C
300°C
200°C
135°C
100°C
85°C
as an example
i Intrinsic safety (ia, ib)
n Non-incentive equipment
m Encapsulation
s Special protection
Minimum EN/
ignition IEC
energy [mJ]
- IIA
0.18 IIA
0.06 IIB
0.02 IIC
EN / IEC
842°F T1
572°F T2
392°F T3
275°F T4
212°F T5
185°F T6
: II 2G E Ex ia IIB T3-T6
31