AREA CLASSIFICATION
Group II Electrical Apparatus
for gas atmospheres ‘G’
Flammable atmosphere
present continously
>1000hrs/annum
Flammable atmosphere
present intermittently
>10<1000hrs/annum
Flammable atmosphere
present abnormally
<10hrs/annum
Code
Standard
IEC/CENELEC/EUROPE
Gas
Dust
Zone 0
Zone 20
Zone 1
Zone 21
Zone 2
Zone 22
IEC 60079-10:2002
IEC 61241-3:1997
North America
NEC Article 500
(Class I)*
A
IIC
HYDROGEN
B
IIB
ETHYLENE
20
C
IIA
PROPANE
20
60
D
180
Protection by gas exclusion - analysers
Powder filled
q
50017
-5
Protection by gas exclusion - weighing machines
Flameproof
d
50018
-1
Prevention of propagation of internal explosion - dc motors
Increased safety
e
50019
-7
Prevention by design - induction motors
Intrinsic safety
ia
50020
-11
Low energy. Safe with two faults - Level measurement
INGRESS PROTECTION
(IP) CODES (IEC/EN 60529)
Intrinsic safety
ib
50020
-11
Low energy. Safe with one fault - displays
50039
-25
Considers combinations of intrinsically safe apparatus
-27
Technical specification. Will move to ‘Standard’ status.
Zone 2 ‘nL’ addition will be proposed (see below FNICO)
FIRST NUMERICAL
SECOND NUMERICAL
Encapsulated
m
50028
-18
Protection by gas exclusion
Protection against solid bodies
Protection against liquid
Type of protection ‘n’
n
50021
-15
Prevention by design
C
O
IIA T1 AMMONIA 630
O
600
O
IIC T1 HYDROGEN 560
IIA T1 METHANE 537
O
NO PROTECTION
0
0
NO PROTECTION
OBJECTS GREATER THAN 5Omm
1
1
VERTICALLY DRIPPING WATER
OBJECTS GREATER THAN 12mm
2
2
ANGLED DRIPPING WATER -75O TO 90O
OBJECTS GREATER THAN 2.5mm
3
3
SPRAYED WATER
OBJECTS GREATER THAN 1.0mm
4
4
SPLASHED WATER
DUST PROTECTED
5
5
WATER JETS
DUST TIGHT
6
T1
450O
NEMA, UL
& CSA type
rating
O
IIA T2 BUTANE 372
IIC T2 ACETYLENE 305
300
T2
300O
200
T3
200O
T4
135O
O
O
IIA T3 KEROSENE 210
O
O
IIB T4 DIETHYL ETHER 160
O
IIC T6 CARBON DISULPHIDE 95
O
100
O
T6
85O
T5
Electrical Installations
-14
-14
New IEC version published 2002
Inspection and maintenance
-17
-17
New IEC version published 2002
8
INDEFINITE IMMERSION
Repair and overhaul
-19
-19
0.2
0.35
T4 CLASSIFICATION
<20mm2
Surface temperature <275OC
>20mm2<10mm2
Surface temperature <200OC
>20mm2
Power dissipation <1.3 W*
0.5
0.7
1
2
5
10
20
O
www.mtl-inst.com
enquiry@mtl-inst.com
*Reduced to 1.2 W with 60 C ambient or 1.0 W with 80 C ambient
The MTL Instruments Group plc
Power Court, Luton, Bedfordshire,
England LU1 3LU
T. +44 (0) 1582 723633
F. +44 (0) 1582 422283
CENELEC
EN
Code
Abbreviated
protection
description
IEC
61241
IEC
MARKING SUB DIVISIONS OF TYPE n
R
R
Restricted breathing
enclosures
L
L
Energy limited apparatus
P
Z
Simplified pressurised
enclosure
C
C
Otherwise protected
sparking apparatus
A
A
Non-sparking apparatus
REMARKS
Enclosure protected - construction and testing
Enclosure protected - selection, installation and maintenance
Electrical apparatus for dusts
-
50281-2-1
-2-1 : 1994
Method for determining minimum ignition temperatures for dust
Electrical apparatus for dusts
-
50281-3
-3 : 1997
Classification of areas where combustible dusts present
Electrical apparatus for dusts
‘pD’
-4 : 2001
Type of protection ‘pD’ - pressurised
-
Basic concepts &
methodology
for all industries
except mining
Basic concepts
& methodology
for mining
Passive components
JB
Well defined sources of stored
energy considered in safety analysis
-1-2 : 1999
Sources of generated energy not
more than *1.5V, 100mA & 25mW
NOT
piezoelectric crystal
protected components
voltage or current enhancement
5Vin
Note: IEC are currently working on a programme to introduce a parallel series of standards for combustible dusts reflecting the IEC 60079 - gas atmosphere standards.
3R
IP24
Outdoor, from rain, sleet & ice damage
4
IP66
Indoor & outdoor, from windblown
dust, rain, splashing & hose directed
water & ice damage
61241-0
Indoor & outdoor, from corrosion,
windblown dust, rain, splashing &
hose directed water & ice damage
61241-1
Protection by enclosure
tD
61241-2
Type of protection ‘pD’ - pressuriastion
pD
61241-10
Area classification
-
61241-11
Intrinsically safe apparatus
iD
61241-14
Selection and installation for electrical
apparatus for dusts
-
61241-17
Inspection and maintenance requirements
-
61241-18
Apparatus protected by encapsulation
61241-20-1
Test methods for dust other parts will also
be generated
They have agreed to re-number the parts as shown below. It is anticipated that a number of these will be published by the end of 2003
Indoor & outdoor, from hose directed
water, water entry during sub-mersion
& ice damage
Indoor, from dust, spraying water, oil
& non-corrosive liquids
3
-1-1 : 1999
Outdoor, from rain, sleet windblown
dust & ice damage
IP54
22
50281-1-2
IP55
13
2
Part 2 -
50281-1-1
3
Indoor, from dust, falling dirt &
dripping non-corrosive liquids
21
EN 1127-2
-
Indoor, limited, falling dirt &water
IP54
1
Explosion prevention
& protection
-
IP22
12
20
Part 1 -
Electrical apparatus for dusts
2
IP67
CENELEC
MARKING
EN 1127-1
Electrical apparatus for dusts
Indoor, from contact with contents
6
Associated apparatus*
*Located in non-hazardous area and may be connected to hazardous area
** Hazardous-area apparatus
Explosion prevention
& protection
REMARKS
IK10
IP20
IP66
Explosion protected
Simple Apparatus
Permitted Zone
ATEX category
1
4X
at 40OC ambient
O
-20
Group II Electrical Apparatus
for combustible dusts ‘D’
Approximate
IEC/IP
classification
100O
SMALL COMPONENT RELAXATION
SURFACE AREA
New IEC version published 2002
EFFECTS OF IMMERSION
O
IIA T3 CYCLOHEXANE 259
-10
HEAVY SEAS
US ENCLOSURE RATINGS
400
O
-10
6
NEMA 7 TO 10 HAZARDOUS AREA ENCLOSURES
O
REMARKS
Classification of hazardous areas
Degrees of protection provided by enclosures for electrical equipment against mechanical impacts
500
IIB T2 ETHYLENE 425
0.14
IEC
60079
7
IK00 IK01 IK02 IK03 IK04 IK05 IK06 IK07 IK08 IK09
*
Protection concept (IS)
CEN
CENELEC
EN 60079
T 4
Explosion Protection - Europe
- Selection, installation, inspection, maintenance
Data for flammable gases
IK code
O
IIA T1 PROPANE 470
Codes of Practice
for gas atmospheres
Mechanical Impacts (IK) Code EN50102
O
O
Fieldbus Intrinsically safe
concept FISCO
II C
Certified to the CENELEC standard
Protection by gas exclusion - transformers
Impact energy (Joules)
O
700
Basic electrical requirements
Intrinsically safe systems
]
Temperature
classification**
Permits combined methods of protection
-2
Equipment is dust-tight and
protected against water jets.
IGNITION TEMPERATURE/
TEMPERATE CLASS (T CLASS)
-0
-6
EXAMPLE IP65
*North America hazard categories: Class I (Gasses & Vapours); Class II (Dusts); Class III (Fibres)
50014
EW
IIC
ACETYLENE
50284
General requirements
50016
Listed in NEC® Article 505-5
Listed in NEC® Article 500-3(c)
i a
Apparatus group
(gas group)
50015
Zone 2
Division 2
E x
3
p
Zone 1
Minimum
ignition energy
(microjoules)
2
2
Category 1G
N
IEC 60079-0
CENELEC
EN50014
1
1
o
Division 1
Typical gas hazard
0
Pressurised
Zone 0
GAS GROUPING
IEC
60079
[E
REMARKS
Oil immersion
NORTH AMERICA
NEC 505 Gas
NEC 500 Gas & Dust
CENELEC
EN
TITLE
IEC PROPOSED
STANDARD
NUMBER
General requirements for electrical apparatus
for use in presence of combustible dusts
Australia
France
Italy
Netherlands
USA
T. +61 (0)8 9455 2994
F. +61 (0)8 9455 2805
T. +33 (0)4 78 64 98 32
F. +33 (0)4 78 35 79 41
T. +39 (0)2 61802011
F. +39 (0)2 61294560
T. +31 (0)48 1450250
F. +31 (0)48 1450260
T. +1 800 835 7075
F. +1 603 926 1899
Canada
Germany
Japan
Singapore
T. +1 905 840 7850
F. +1 905 840 7852
T. +49 (0)2131 718930
F. +49 (0)2131 7189333
T. +81 (0)3 5420 1281
F. +81 (0)3 5420 2405
T. +65 6 487 7887
F. +65 6 487 7997
China
India
Middle East
UK
T. +86 010 8562 5718
F. +86 010 8562 5725
T. +91 (0)44 24501660
F. +91 (0)44 24501436
T. +971 2 63 22399
F. +971 2 63 22566
T. +44 (0)1582 407298
F. +44 (0)1582 407222
PROPOSED
STATUS
CODE
-
WORK IN PROGRESS
Guideline figures
Certification Code
Permitted Zone
ATEX category
}
IEC
STANDARD
NUMBER
Fieldbus in hazardous areas
The Fieldbus Intrinsically safe Concept
(FISCO) IEC60079-27 Technical
Enclosure protected, temperature limitation - construction
and testing
Specification will move to ‘Standard’
61241-4
Type of protection ‘pD’
status in the near future. The benefits
61241-3
Area classification
from FISCO will be extended to include
-
similar levels of flexibility in Zone 2 and
Selection, installation and maintenance of apparatus meeting
IEC61241-1-1 above
Division 2. Further details are contained
-
and AN9027 FNICO (Fieldbus Non-
61241-1-2
mD
-
TITLE
61241-1-1
-
}
*Note: North America still uses 1.2V and 20 microjoules
61241-2-1
Methods for determining minimum ignition temperatures
of dust
For technical advice
or further information call:
+44 (0) 1582 723633
in MTL Application Notes AN9026 FISCO
Incendive Concept)
International (IEC) standards
www.iec.ch
European (CENELEC) standards
www.cenelec.org
National Electrical Codes (NEC®)
www.nfpa.org/catalog/home/index.asp
20Vout