5
3. INTRINSIC SAFETY CERTIFICATION
3.1 ATEX certificate
The BA488CF-P has been issued with EC-Type
Examination Certificate by Notified Body Intertek
Testing Services (ITS) confirming compliance with
the European ATEX Directive 94/9/EC for Group II,
Category 1, gas atmospheres, EEx ia IIC T4. The
instrument 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 manual
describes installations which conform with
EN 60079: Part 14 Electrical Installation in
Hazardous Areas. When designing systems for
installation outside the UK, the local Code of
Practice should be consulted. Some of the
standards specified may have subsequently been
deharmonised, please see BEKA Declaration of
Conformity for current conformity.
3.2 Zones, gas groups and T rating
The BA488CF-P has been issued with EC Type
Examination certificate ITS04ATEX22779
confirming that it complies with the requirements
for Group II Category 1 G Ex ia IIC T4 (Tamb –40
to 60°C) specified in the ATEX Directive. When
connected to a suitable system the BA488CF-P
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
450°C
T2
300°C
T3
200°C
T4
135°C
At an ambient temperature between –40 and
+60°C.
Note
: the guaranteed operating temperature range
of the Fieldbus Display is –20 to +60°C
This allows the BA488CF-P to be installed in all
Zones and to be used with most common industrial
gases.
WARNING installation in Zone 0
When installed in a Zone 0 potentially
explosive atmosphere requiring apparatus
of Category 1G, the fieldbus display shall be
installed such that even in the event of rare
incidents, an ignition source due to impact
or friction between the aluminium enclosure
at the rear of the instrument mounting panel
and iron/steel is excluded.
3.3 Fieldbus connection
The BA488CF-P PROFIBUS display is powered
and communicates via the fieldbus, which is
connected to terminals 1 and 2. These terminals
comply with the Fieldbus Intrinsically Safe Concept
(FISCO) defined in EN 60079 Part 27, which
simplifies intrinsic safety system design.
The BA488CF-P may also be connected to non
FISCO compliant fieldbus segments by using the
entity concept to assess safety.
Terminals 1 and 2 of the BA488CF-P Fieldbus
Display are not polarised and have the following
safety parameters:
Ui
=
17.5V dc
Ii
=
380mA dc
Pi
=
5.32W
For non FISCO compliant segments, the safety
parameters of the power supply or isolator
powering the fieldbus segment must be equal to or
less than these figures.
The maximum equivalent capacitance and
inductance at terminals 1 & 2 of the BA488CF-P
Fieldbus Display are:
Ci
= 1nF
Li
= 8µH
To determine cable parameters for non FISCO
compliant segments, the sum of Ci and Li of all the
field devices should be subtracted from the
maximum cable parameters permitted by the
device powering the fieldbus segment.
3.4
External switches
For applications requiring operator inputs to be
made by large industrial push buttons, terminals
S1 to S7 facilitate external switches to be
connected to the Fieldbus Display. When external
switches are connected, the BA488CF-P may be
configured so that the front panel push buttons
continue to function or are disabled.
Terminals S1 to S7 have the following combined
output safety parameters: