BEKA BA314E, Manual

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APPENDIX 1
ATEX Dust Certification
A1.0 ATEX dust certification
In addition to ATEX certification permitting installation
in explosive gas atmospheres which is described in
the main section of this instruction manual, the
BA314G Tachometer also has ATEX dust certification.
A1.1 Zones, and Maximum Surface
Temperature.
The BA314G has been certified
Group II Category 1D Ex ia IIIC T80°C Da
Ta = -40º to 60ºC. When connected to a suitable
system it 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 dust in subdivisions:
IIIA combustible flyings
IIIB non-conductive dust
IIIC conductive dust
Having a Minimum Ignition Temperature of:
Dust cloud 120°C
Dust layer on Rate 155°C
Totaliser up to 5mm thick
Dust layer on Rate Refer to
Totaliser over 5mm thick. EN 60079-14
At an ambient temperature between -40 and +60°C
A1.2 Installation and maintenance
The installation requirement described in this manual
for use in a gas potentially explosive atmospheres
also apply when the Tachometer is installed in a dust
potentially explosive atmosphere.
The instrument assembly should only be removed
from the enclosure back-box when dust can not
enter the instrument enclosure. Before replacing the
instrument assembly the sealing gasket should be
inspected to ensure that it is undamaged and free
from foreign bodies.
It is good practice to prevent dust accumulating on
the Tachometer enclosure. If this can not be
avoided, care should be taken to ensure that the
layer thickness does not exceed 5mm for dusts
having a minimum ignition temperature of 155°C.
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