Westermo RFI-xx - Manual (Page 6)

6 6641-22305
General
This unit is intended for use in zone 2 and zone 22 hazardous location only.
Marking
ii 3 GD
ex nA iiC T4 Gc
ex tc iiiC Dc
sPeCiAL CONDiTiON
WArNiNG – DO NOT sePArATe WHeN eNerGiZeD
ATEX Information
indicate that this unit complies with relevant european standards that are
harmonized with the 94/9/eC Directive (ATeX).
II
equipment group ii.
This unit can be installed in all places with an explosive gas or dust atmos-
phere 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.
GD
indicates protection concerning explosive atmospheres caused by gases,
vapours or mists (G) and dust mixtures (D).
Ex indicates that this unit is in conformity with relevant european ex standard(s).
nA
Type of protection used.
This unit is a non-sparking device "nA" which is constructed to minimize the
risk of occurrence of arcs or sparks capable of creating an ignition hazard dur-
ing 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
occurrences. ePL Gc are analogous to the ATeX Categories
(Category 3 G = ePL Gc).
tc Dust protection provided by external enclosure.
IIIC Dust group, conductive dust.