5
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 BA364D input parameters.
To comply with certification requirements, all
transducers and associated field wiring
connected to the BA364D 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
H
When installing systems not covered by the
BA364D system certificates, these figures must
be subtracted from the maximum cable
parameters for the certified device connected to
the BA364D input.
1.4.4 Remote reset terminals
When programmed as a counter, timer or clock
the BA364D 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 BA364D 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 BA364D 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
+60
o
C.
Note
: the guaranteed operating temperature
range is –20 to +60
o
C
This allows the BA364D to be installed in all
Zones and to be used with most common
industrial gases.
1.4.6 Certification label Information
The certification label is fitted in a recess on the
top of the enclosure. It shows the ATEX
certification information, BEKA associates name
and web site address. Non European certification
information may also be included. The
instrument serial number and date of
manufacture are recorded on a separate label
inside the terminal compartment