Instruction sheet for BA369
Intrinsically safe battery powered clock
1.
INTRODUCTION
The BA369 is an intrinsically safe, battery powered digital clock which can
display local time in a hazardous area. It is a self contained panel
mounting instrument with a selectable twelve or twenty four hour display.
All controls are located on the front panel and may be protected by a
security code to prevent unauthorised adjustment.
If required the display may be synchronised to a master clock via a simple
external contact closure.
The BA369 clock is ATEX certified Group II Category 1G, EEx ia IIC T5
allowing installation in all Zones and use with most hazardous gases.
2.
INTRINSIC SAFETY CERTIFICATION
2.1
ATEX certificate
The BA369 clock has been issued with EC-Type Examination Certificate
number ITS02ATEX2017 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 T5. 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.
i.e. Austria, Belgium, Denmark, Finland, France, Germany, Greece,
Ireland, Italy, Luxembourg, Norway, The Netherlands, Portugal, Spain,
Sweden and the United Kingdom. ATEX certificates are also accepted in
Iceland, Liechtenstein, Switzerland and the Czech Republic.
This instruction sheet describes installations which conform with BS
EN60079:Part 14 Electrical Installation in Hazardous Areas. When
designing systems for installation outside the UK, the local Code of
Practice should be consulted.
2.2
Zones, Gas Groups and T rating
The BA369 clock has been certified EEx ia IIC T5 and 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, it 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
Although certified intrinsically safe at ambient temperatures between –40
and +50ºC the guaranteed operating temperature range of the clock is
–20 to +50ºC.
WARNING installation in Zone 0
When installed in a Zone 0 potentially explosive atmosphere
requiring apparatus of Category 1G, the clock 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
.
2.3
Internal battery
The BA369 is powered by a replaceable intrinsically safe battery which will
operate the clock for at least two years. A replacement intrinsically safe
battery may be installed while the clock is mounted within the hazardous
area. See section 6.1 for detailed instructions.
2.4
Synchronising terminals
Connecting terminals 1 and 2 together will stop the clock. When the
terminals are disconnected the clock will re-start from a new time selected
in the programme menu. This may be the nearest minute or the nearest
hour to the original display, or a preset time may be entered during
programming. This function allows a BA369 clock to to be synchronised
with a master clock.
In addition to the EC-Type Examination Certificate, ITS have issued two
System Certificates illustrating how the synchronising terminals of up to
ten BA369 clocks may be interconnected within the hazardous area.
These certificates are only for guidance and are not part of the BA369
ATEX certification.
Fig 1 shows how up to ten BA369 clocks may be synchronised by a
mechanically operated hazardous area switch. Any switch may be used
providing it has IP20 protection and will withstand a 500V rms insulation
test for one minute.
Fig 1 Synchronising display from hazardous area
If the synchronising switch is located in the safe area, the contact closure
must be transferred to the hazardous area via a certified intrinsically safe
Zener barrier or galvanic isolator. Any single channel Zener barrier
certified EEx ia by a European Notified Body may be used providing its
safety output parameters do not exceed:
Uo
=
10V dc
Io
=
200mA dc
Po
=
0.7W
To synchronise up to ten clocks the ‘on’ resistance of the switch plus the
end-to-end resistance of the Zener barrier must be less than 500
and the
‘off’ resistance must be greater than 30k
. See Fig. 2 and System
Certificate Ex02E2018.
Fig 2 Synchronising display from safe area via Zener barrier
As shown in Fig 3 a galvanic isolator or intrinsically safe relay may also be
used to transfer the synchronising switch contact closure into the
hazardous area. System Certificate Ex02E2019 lists some suitable
devices, but others may be used.
The BA369C clock is CE marked to show compliance with the
European Explosive Atmospheres Directive 94/9/EC and the
European EMC Directive 2004/108/EC
BEKA associates Ltd, Old Charlton Road, Hitchin, Herts. UK SG5 2DA. Tel: +44 (0) 1462 438301 www.beka.co.uk
