BEKA BA368C, Руководство пользователя

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Voltage pulses may be connected to one or both
inputs. They must be from a certified intrinsically
safe source within the hazardous area, or
connected via a Zener barrier or galvanic isolator
from any safe area pulse source. The output
parameters of the barrier or isolator must be less
than the BA368C input parameters.
To comply with certification requirements, all
transducers and associated field wiring connected
to the BA368C input terminals must be able to
withstand an ac test voltage of 500V rms to earth
or frame of the apparatus for one minute. The
maximum equivalent capacitance and inductance
between the pulse input terminals 3 & 4 and 5 & 6
is:
Ci = 20nF
Li = 20
µ
H
When installing systems not covered by the
BA368C system certificates, these figures must be
subtracted from the maximum cable parameters
for the certified device connected to the BA368C
input.
1.4.4 Remote reset terminals
When programmed as a counter, timer or clock the
BA368C display can be reset or synchronised by
connecting terminals 7 and 8 together for more
than one second. These terminals have the
following input and output safety parameters:
Ui = 28V dc
Ii = 100mA dc
Pi = 0.7W
Uo = 3.8V dc
Io = 1.7mA dc
Po = 2.0mW
The display may be reset from within the
hazardous area by any mechanically operated
switch connected directly to terminals 7 & 8.
To reset the display from the safe area a Zener
barrier or intrinsically safe relay is required to
transfer the contact closure into the hazardous
area. Almost any intrinsically safe relay with
certification permitting the contacts to be
connected to equipment in the hazardous area
may be used. A positive diode return Zener barrier
may also be used. The system certificates list
suitable devices and define the maximum cable
parameters.
1.4.5 Zones, gas groups and T rating
The BA368C has been certified compliant with the
requirements for Group II, Category 1 G, EEx ia
IIC T5 (Tamb –40 to 60
o
C) equipment specified by
the ATEX Directive. When connected to a suitable
system the BA368C 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
T5 100°C
At an ambient temperature between –40 and
+60
o
C.
Note : the guaranteed operating temperature
range is –20 to +60
o
C
1.4.6 Certification label Information
The certification label is fitted in a recess on the
top of the enclosure.
WARNING installation in Zone 0
When installed in a Zone 0 potentially
explosive atmosphere requiring apparatus
of Category 1G, the instrument 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.