Westermo DDW-142-EX - Manual (Page 8)

8 6642-22521
General
This unit is intended for use in Zone 2 hazardous location only.
Marking
II 3G
Ex nA IIC T4 Gc
SPECIAL CONDITION
ATEX Information
Indicate that this unit complies with relevant European standards that are
harmonised with the 94/9/EC Directive (ATEX).
II
Equipment group II.
This unit can be installed in all places with an explosive gas atmosphere other
than mines susceptible to firedamp.
3
Equipment category 3.
A category is the classification according to the required level of protection.
This unit ensures the requisite level of protection during normal operation and
is intended for use in areas in which explosive atmosphere caused by gases,
vapours, mists, or dust mixtures are unlikely to occure or, if they do occure, are
likely to do so only infrequently and for a short periode only.
G
Indicates protection concerning explosive atmospheres caused by gases,
vapours or mists (G).
Ex Indicates that this unit is in conformity with relevant European Ex standard(s).
nA
The type of protection used.
This unit is a non-sparking device "nA" which is constructed to minimize the risk
of occurence of arcs or sparks capable of creating an ignition hazard during
conditions of normal operation.
IIC Gas group, a typical gas i hydrogen.
T4
Temperature class T4 (T4 = 135 °C).
This unit is classified in accordance with its maximum surface temperature
(external and internal).
Gc
Equipment protection level Gc (EPL Gc).
Equipment for explosive gas atmospheres, having a "enhanced" level of
protection, which is not a source of ignition in normal operation and which may
have some additional protection to ensure that it remains inactive as an ignition
source in the case of regular expected occurences.
EPL Gc are analogous to the ATEX Categories (Category 3 G = EPL Gc).
SPECIAL
CONDITION
This unit has a special condition for safe use.
The special condition for safe use contains safety related information that is
necesarry for the correct installation and safe use.