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A3.2 IECEx dust certification
In addition to IECEx certification permitting
installation in explosive gas atmospheres, the
BA474D is available with optional IECEx certification
permitting use in the presence of combustible dusts.
The IECEx Certificate of Conformity specifies the
following certification codes and marking:
Intrinsic safety dust
Ex ia IIIC T80
o
C Da IP66
certification.
Associated apparatus [Ex ia Da] IIIC 20
o
C
dust certification.
Ta -20
o
C to +60
o
C
If IECEx dust certification is required it must be
requested when the BA474D Indicating Temperature
Transmitter is purchased.
WARNING
Before installing a BA474D Indicating
Temperature Transmitter in the presence of
a combustible dust, ensure that the
certification information label, which is
located on the top of the instrument,
specifies dust certification - see below.
When connected to a certified IECEx system the
BA474D may be installed in:
Zone 20 explosive atmosphere in the
form of a cloud of
combustible dust in air is
continuously present, or for
long periods or frequently.
Zone 21 explosive atmosphere in the
form of a cloud of
combustible dust in air is
likely to occur occasionally
in normal operation.
Zone 22 explosive atmosphere in the
form of a cloud of
combustible dust in air is not
likely to occur in normal
operation, but if it does
occur, will only persist for a
short period.
Be used with dusts having a Minimum Ignition
Temperature of:
Dust cloud
120
o
C
Dust layer on BA474D
155
o
C
up to 5mm thick
Dust layer on BA474D
Refer to
over 5mm thick.
EN 61241-14
At an ambient temperature between -20 and +60
o
C
A3.4 Installation & maintenance
The IECEx dust certification relies on the BA474D
Indicating Temperature Transmitter enclosure being
dust-tight. Therefore the terminal cover should only
be removed when dust can not enter the instrument
enclosure. Before replacing the terminal cover ensure
that the sealing gaskets are undamaged and are free
from foreign bodies.
