Lektors: Elvinas Šabasevičius (Slovākija)

1. www.scame.com
Basic concepts for explosion protection
1

2. www.scame.com
Basic concepts for explosion protection
2
Potentially explosive atmospheres
LEL : Lower Explosive Level
(Low Mixture)
UEL : Upper Explosive Level
(Rich Mixture)

3. www.scame.com
Basic concepts for explosion protection
3
Gas/Vapour
Apparatu
s group
Temperatu
re class
Dusts
Typical Ignition
Temperature (°C)
Cloud Layer
Acetic Acid IIA T1 Aluminium 590 >450
Acetone IIA T1 Coal dust (lignite) 380 225
Acetylene IIC T2 Flour 490 340
Ammonia IIA T1 Grain dust 510 300
Butane IIA T2 Methyl cellulose 420 320
Cyclohexane IIA T3 Phenolic resin 530 >450
Ethanol (ethyl alcohol) IIA T2 Polythene 420 (melts)
Ethylene IIB T2 PVC 700 >450
Hydrogen IIC T1 Soot 810 570
Kerosene IIA T3 Starch 460 435
Methane (natural gas) (non-
mining)
IIA T1 Sugar 490 460
Methanol (methyl alcohol) IIA T2
Methyl ethyl ketone
(MEK)
IIB T2
Propane IIA T1
Propan-1-ol (n-propyl
alcohol)
IIB T2
Propan-2-ol (iso-propyl
alcohol)
IIA T2
Tetrahydrofuran (THF) IIB T3
Toluene IIA T1
Xylene IIA T1
Apparatus groups & temperature classes
MICR: Minimum Ignition Current Ratio
IIA : Min. 180uJ
IIB : Min. 60uJ
IIC : Min. 20uJ
Human body’s capacity is around 300pF
Static sparks generated can reach up to
330uJ with a voltage of 1500 V…..

4. www.scame.com
Basic concepts for explosion protection
4
Temperature classes
Maximum surface temperature
T. Codes
CENELEC IEC
450°C T1
300°C T2
200°C T3
135°C T4
100°C T5
85°C T6
N.B. For Group I applications apparatus has rigid 150°C and 450°C limits rather than “T”
classes.

5. www.scame.com
Basic concepts for explosion protection
5
ATEX
ATEX 94/9/EC
(ATEX 100a)
SA Products directive
Covers manufacturers health and safety
requirements
ATEX 100a
Product directive
SA Products requirements
ATEX 199/92/EC
(ATEX 137)
SA Workers directive
Covers and users minimum requirements for
health and safety protection of workers
ATEX 137
Workers directive
SA Risks analysis
Product test
Quality audit
Certificates documentation instructions
Zones identification
Assessment
Explosion protection document

6. www.scame.com
Basic concepts for explosion protection
6
Gives the minimum requirements in the field of safety and health protection of workers
potentially at risk from explosive atmospheres.
Define obbligation of the employer
Defines Zones and criteria for selection of equipment and protective systems
DIRECTIVE 1999/92/EC OF THE EUROPEAN PARLIAMENT
AND OF THE COUNCIL
dated 16 December 1999
on minimum requirements to improve the safety and health protection of workers potentially at
risk of explosive atmospheres (15th individual Directive within the meaning of Article 16(1) of
Directive 89/391/EEC)

7. www.scame.com
Basic concepts for explosion protection
7
Applies to equipment and protective systems intended for use in potentially explosive
atmospheres .
Covers all risk of explosion (not only those from electrical origin)
Covers both application for mines and for other application
Applies to equipment, components, safety devices, controlling devices and regulating
devices .
DIRECTIVE 94/9/EC OH THE EUROPEAN PARLIAMENT
AND THE COUNCIL
dated 23 March 1994
on the approximation of the laws of the Member States concerning equipment and protective
systems intended for use in potentially explosive atmospheres

8. www.scame.com
Basic concepts for explosion protection
8
Group and equipment category
Group I
Mines and surface
installations of such mines
Group II
Other places
Category M1
very high level of protection
Category M2
high level of protection
Category 1
very high level of protection
Category 2
high level of protection
Category 3
normal level of protection

9. www.scame.com
Basic concepts for explosion protection
9
Group II - Zones
GAS DUST
Frequency and
duration of the
occurrence of an
explosive
atmosphere
0 20
present
continuously or for
long periods or
frequently.
1 21 occasionally
2 22 not likely to occur

10. www.scame.com
Basic concepts for explosion protection
April 8°, 200910

11. www.scame.com
Basic concepts for explosion protection
11
Group II – Categories - Zones
Category GAS DUST
Frequency and
duration of the
occurrence of
an explosive
atmosphere
Level of
protection
1 0 20
present
continuously
or for long
periods or
frequently.
- very high
- 2 means of prot.
- 2 faults
2 1 21 occasionally
- high
- 1 mean of prot.
- 1 fault
3 2 22
not likely to
occur
- normal
- guaranteed in
normal operation

12. www.scame.com
Basic concepts for explosion protection
12
Standards
GAS DUST
EN 60079 Series EN 61241 Series
Both series of Standards consists of a “General requirements” part and of
different specific parts to cover:
- different types of protection
- installation and classification of areas
- maintenance

13. www.scame.com
Basic concepts for explosion protection
April 8°, 200913
12 persons involved:
11 deads (7 workers, 3 external, 1 fisherman), 1 blessed
Possible reasons:
Formation of combustible gas and autoignition
Air/dust mix
Frictions or mechanical parts touching into air cooling system
Esplosion of a silos of corn:
Blaye – France, 1997
40.000 t of corn out of 130.000 t …
Explosive dusts … example of danger………..

14. www.scame.com
Basic concepts for explosion protection
14
“ZENITH P” as “Component”
Material of the enclosure : Resin SMC LS3806 R28C NERO
Material of the gasket: Silicone rubber gasket without joint (Mesgo –
MG8446N30) – (delivered in the cover)
Via Costa Erta 15 Parre BG ITALY
Cod. 644.xxxx Year xxxx
S/N xxxxxxxxx
SIRA08ATEX3041U
0051
Ex e II Ta -60° to +75°C
Ex ia IIC Ta -60° to +75°C
Ex tD A21 IP66 II 2 GD
Label placed internally on the base
Material of the label: Fasson
Transfer PET Matt Chrome
TOP/AL170 BG42 White.
As option:
Label plate in S.S. AISI316
Laser marking

15. www.scame.com
Basic concepts for explosion protection
15
“ZENITH P “as “Equipment “
Via Costa Erta 15 Parre BG ITALY
Cod. 644.xxxx-yyy Year xxxx
S/N xxxxxxxxx V xxxx V
SIRA08ATEX3042 I xxxx A
P max xxxx W
0051
Ex e II Tx Ta -xx° to +xx°C
Ex tD A21 IP66 Tyy°C II 2 GD
DO NOT OPEN WHEN ENERGIZED
IN PRESENCE OF EXPLOSIVE ATMOSPHERE
Material of the enclosure : Resin SMC LS3806 R28C NERO
Material of the gasket: Silicone rubber gasket without joint (Mesgo –
MG8446N30) – (delivered in the cover)
Label placed outside on the cover
and internally on the base
Material of the label: Fasson
Transfer PET Matt Chrome
TOP/AL170 BG42 White.
As option:
Label plate in S.S. AISI316
Laser marking

16. www.scame.com
Basic concepts for explosion protection
16
ta 15 Parre BG ITALY Via Costa Erta 15 Parre BG ITALY
Cod. 644.xxxx-yyy Year xxxx
S/N xxxxxxxxx V xxxx V
SIRA08ATEX3042 I xxxx A
P max xxxx W
0051
Ex e II Tx Ta -xx° to +xx°C
Ex tD A21 IP66 Tyy°C II 2 GD
DO NOT OPEN WHEN ENERGIZED
IN PRESENCE OF EXPLOSIVE ATMOSPHERE
T4, T5 o T6
-50°C o –60°C
to
+40°C, +60°C o
+75°C
80°C, 95°C o
130°C
Tx e Tyy depends on Ta:
Ta=40°C we can have T6 and T80°C
Ta=60°C we can have T6 or T5 and T95°C
Ta=75°C we can have T4 and T130°C
Year= year of
production
V= Rated voltage (V)
I= Rated current
P max= maximum
dissipable power
depending on Ta and
T class (see following
tables)
ZENITH P as “Equipment “

17. www.scame.com
Increased Safety Ex e Enclosures & Junction Boxes
ZENITH P
ATEX - Ex
SCAME Offer

18. www.scame.com
Increased Safety Ex e Enclosures & Junction Boxes
ZENITH P

19. www.scame.com
Increased Safety Ex e Enclosures & Junction Boxes
ZENITH P

20. www.scame.com
Increased Safety Ex e Enclosures & Junction Boxes
ZENITH P

21. www.scame.com
Basic concepts for explosion protection
April 8°, 200921

22. www.scame.com
Basic concepts for explosion protection
April 8°, 200922

23. www.scame.com
Basic concepts for explosion protection
23
EXAMPLES OF APPLICATION

24. www.scame.com
Basic concepts for explosion protection
24
EXAMPLES OF APPLICATION

25. www.scame.com
Basic concepts for explosion protection
25
EXAMPLES OF APPLICATION

26. www.scame.com
Basic concepts for explosion protection
26
EXAMPLES OF APPLICATION

27. www.scame.com
Basic concepts for explosion protection
27
EXAMPLES OF APPLICATION

28. www.scame.com
Basic concepts for explosion protection
28
EXAMPLES OF APPLICATION

29. www.scame.com
Basic concepts for explosion protection
29
EXAMPLES OF APPLICATION

30. www.scame.com
Basic concepts for explosion protection
30
EXAMPLES OF APPLICATION

31. www.scame.com
Basic concepts for explosion protection
31
EXAMPLES OF APPLICATION

32. www.scame.com
Basic concepts for explosion protection
32
Elvinas Šabasevičius
elvinas@scame.sk