4
4. INTRINSIC SAFETY CERTIFICATION
The BA474D Indicating Temperature Transmitter is
intrinsically safe allowing installation in Zone 0, 1 or 2
when protected by a safe area Zener barrier or
galvanic isolator.
The transmitter is also certified as associated
apparatus, which when mounted in a safe area,
allows the input terminals to be directly connected to
a sensor in Zone 0, 1 or 2 without the need for Zener
barriers or galvanic isolators.
4.1 ATEX certificate
Notified Body Intertek Testing and Certification Ltd
have issued the BA474D with an EC-Type
Examination Certificate number ITS09ATEX26155.
This states that the transmitter is intrinsically safe and
complies with requirements for Group II, Category
1GD Ex ia IIC T5 equipment, and that it also
complies with the requirements for intrinsically safe
associated apparatus. The transmitter bears the
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 main section of this instruction manual describes
ATEX installations in explosive gas atmospheres
conforming with EN 60079-14 Electrical Installations
in Hazardous Areas. When designing systems for
installation outside the UK the local Code of Practice
should be consulted.
For use in the presence of combustible dust, please
refer to Appendix 1, which describes ATEX
installations complying with EN 61241-14. Dust
certification is an option that must be specified when
the transmitter is ordered.
4.2 Zones, gas groups and T rating
The BA474D has been certified as Group II Category
1G Ex ia IIC T5 apparatus. When connected to a
suitable certified system the BA474D 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.
Be used with gases in groups:
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 an ambient temperature between –40 and +70ºC.
This allows the BA474D to be installed in all Zones
and to be used with most common industrial gases.
4.3 Associated apparatus
The ATEX certificate also states that the BA474D
Indicating Transmitter complies with the requirements
for associated apparatus as it has a galvanically
isolated intrinsically safe sensor input. When
installed in a safe area this allows the transmitter
sensor input, terminals 1, 2, 3 & 4, to be connected
directly, without the need for Zener barriers or
galvanic isolators, to a sensor 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.
With a gas in groups:
Group A propane
Group B ethylene
Group C hydrogen
