Unit Categories; Temperature Classes - WAGO 750 Series Manual

Hydrogen being commonly encountered in chemical plants, frequently the
explosion group IIC is requested for maximum safety.

9.3.3 Unit categories

Moreover, the areas of use (zones) and the conditions of use (explosion
groups) are subdivided into categories for the electrical operating means:
Unit
categories
M1
M2
1G
2G
3G
1D
2D
3D

9.3.4 Temperature classes

The maximum surface temperature for electrical components of explosion
protection group I is 150 °C (danger due to coal dust deposits) or 450 °C (if
there is no danger of coal dust deposit).
In line with the maximum surface temperature for all ignition protection types,
the electrical components are subdivided into temperature classes, as far as
electrical components of explosion protection group II are concerned. Here the
temperatures refer to a surrounding temperature of 40 °C for operation and
testing of the electrical components. The lowest ignition temperature of the
existing explosive atmosphere must be higher than the maximum surface
temperature.
Temperature classes
T1
T2
T3
T4
T5
T6
WAGO-I/O-SYSTEM 750
ETHERNET TCP/IP
Classification meeting CENELEC and IEC
Explosion Area of use
group
I Fire-damp protection
I Fire-damp protection
II Zone 0 Explosive environment by gas, fumes or mist
II Zone 1 Explosive environment by gas, fumes or mist
II Zone 2 Explosive environment by gas, fumes or mist
II Zone 20 Explosive environment by dust
II Zone 21 Explosive environment by dust
II Zone 22 Explosive environment by dust
Maximum surface
temperature
450 °C
300 °C
200 °C
135 °C
100 °C
85°C
Use in Hazardous Environments
Ignition temperature
of the combustible materials
> 450 °C
> 300 °C to 450 °C
> 200 °C to 300 °C
> 135 °C to 200 °C
>100 °C to 135 °C
> 85 °C to 100 °C
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