BEKA BA337E, Manual

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3. INTRINSIC SAFETY CERTIFICATION
The BA337E and the BA338E rate totalisers have
ATEX and IECEx gas certification. This section of the
instruction manual describes ATEX gas certification.
IECEx and other approvals are each described in
separate appendixes to this manual.
3.1 ATEX gas certification
Notified Body Intertek Testing and Certification Ltd
have issued the BA337E and the BA338E with an
EC-Type
Examination Certificate number
ITS16ATEX28408X. This confirms compliance with
harmonised European standards and it has been
used to confirm compliance with the European ATEX
Directive for Group II, Category 1G equipment. The
Rate Totalisers carry the European Community mark
and subject to local codes of practice may be installed
in any of the European Economic Area (EEA) member
countries. ATEX certificates are also acceptable for
installations in Switzerland.
This section of the instruction manual describes ATEX
installations in explosive gas atmospheres complying
with EN60079-14
Electrical Installation Design,
Selection and Erection.
When designing systems for
installation outside the UK the local Code of Practice
should be consulted.
3.2 Zones, gas groups and T rating
The BA337E and BA338E Rate Totalisers have been
certified Ex ia IIC T5 Ga -40ºC
≤ Ta ≤ +70ºC. When
connected to a suitable system they may be installed
in:
Zone 0 explosive gas air mixture
continuously present.
Zone 1 explosive gas air mixture likely
to occur in normal operation.
Zone 2 explosive gas air mixture not
likely to occur, and if it does
will only exist for a short time.
In gases that may be used with equipment having a
temperature classification of:
Group A propane
Group B ethylene
Group C hydrogen
Having a temperature classification of:
T1 450ºC
T2 300ºC
T3 200ºC
T4 135ºC
T5 100ºC
At ambient temperatures between -40 and +70ºC.
Note:
The specified operating temperature of the
BA337E and BA338E is -40 to +70°C. At
temperatures below -20°C the instruments will
continue to function, but the display digits will
change more slowly and contrast will be reduced.
This allows the Rate Totalisers to be installed in all
gas Zones and to be used with most common
industrial gases except carbon disulphide and ethyl
nitrite which have an ignition temperature of 95ºC.
3.3 Special conditions for safe use
The ATEX certificate has an ‘X’ suffix indicating that
special conditions apply to prevent an electrostatic
charge developing on the outside of the instrument
enclosure.
WARNING
To avoid an electrostatic charge being
generated instrument enclosure should
only be cleaned with a damp cloth.
3.4 Power supply
When installed in a hazardous area the BA337E and
the BA338E should be powered from a certified
Zener barrier, galvanic isolator or associated
apparatus with an intrinsically safe voltage output.
The safety parameters of terminals 1 and 2 are:
Ui = 28V dc
Ii = 200mA dc
Pi = 0.84W
Uo = 0
Io = 0
Any certified Zener barrier, galvanic isolator or
associated apparatus with output safety parameters
equal to or less than these input limits may be used.
The maximum equivalent capacitance and
inductance between terminals 1 and 2 is:
Ci = 2nF
Li = 4µH
To determine the maximum permissible cable
parameters the above figures, which are small and
may be ignored in some applications, should be
subtracted from the maximum permitted cable
parameters specified for the Zener barrier, galvanic
isolator or associated apparatus powering the
BA337E or BA338E Rate Totaliser.
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