Ignition sources
Classification of Ignition Sources for gas and vapour

 

 

Hot surfaces

Ignition temperature

   

          Sparks         

          Ignition         

          Energy         

↓

  

↓

Temperature Class

T1 ... T6

  

Gas Group

A ... C

 

Temperatur Class

 

 

Temperatur class

Maximum surface temperature

(at max. ambient temperature)

T1

450°C

T2

300°C

T3

200°C

T4

135°C

T5

100°C

T6

85°C

 

Energy Classification

 

 

Minimum Ignition Energy

European Groups

USA/Canada Groups

Gas e.g.
< 20 μ Joules

C

A

 Acetylene, Carbon disulphide
< 20 μ Joules

B

 Hydrogen
< 60 μ Joules

B

C

 Ethylether, Ethylene
< 180 μ Joules

A

D

 Acetone, Butane, Ethanol, Gasoline, Hexane, Methanol, Methane, Naphtha, Propane

 

Standards valid for

 

 

Electrical Apparatus for Explosive Gas Atmospheres

EN (old)

EN (new)
General requirements EN 50014 EN 60079-0
Flameproof enclosures "d" EN 50018 EN 60079-1
Pressurized enclosures "p" EN 50016 EN 60079-2
Powderfilling "q" EN 50017 EN 60079-5
Oil immersion "o" EN 50015 EN 60079-6
Increased safety "e" EN 50019 EN 60079-7
Intrinsic safety "i" EN 50020 EN 60079-11
Type of protection "n" EN 50021 EN 60079-15
Encapsulation "m" EN 50028 EN 60079-18
Intrinsically safe systems EN 60079-25
Electrical equipment for Zone 0 EN 50284 EN 60079-26
Intrinsically safe field bus systems EN 60079-27
Optical radiation "op" EN 60079-28

 

 

Standards valid for electrical apparatus for Explosive dust atmosphere

 

 

Standard EN (IEC)

Protection name

Protection method
61241-0 General requirements for Dust equipment
61241-1 / 60079-31

tD

 Protected by enclosures
61241-2

pD

 Protected by pressurization
61241-11

iD

 Protected by intrinsic safety
61241-18

mD

 Protected by encapsulation

 

 

Standards valid for mechanical equipment

 

 

Protection type

EN 13463-

Marking letter
Construction

EN 13463-5

c
Inherent safety

EN 13463-4

g
Flow restriction

EN 13463-2

fr
Pressurization

EN 13463-7

p
Flameproof

EN 13463-3

d
Controlled ignition

EN 13463-6

b
Protected by oil

EN 13463-8

k

 

 

Combustion motors

 

 

EN 1834-1 Gas, group II
EN 1834-2 Gas, group I
EN 1834-3 Dust, group III