BEKA BA344D, Руководство пользователя

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6
3.4 Remote reset terminals
The BA344D total display may be reset to zero
by connecting the reset terminals 7 and 8
together. These two terminals have the
following input and output safety parameters:
Uo = 3.7V dc
Io = 3.7mA dc
Po = 3.5mW
Ui = 28V dc
Ii = 100mA dc
Pi = 0.7W
The maximum equivalent capacitance and
inductance between them is:
Ci = 30nF
Li = 10
µ
H
The total display may be reset to zero from
within the hazardous area by any mechanically
operated switch connected directly to terminals
7 and 8. The switch and associated wiring
must be capable of withstanding a 500V rms
insulation test to earth for one minute and have
IP20 protection.
To reset the total 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 as shown in
Fig 3. The system certificates list suitable
devices and define the maximum cable
parameters.
Notes:
The BA344D may be programmed so that the
total display is reset to zero when the
Up and
Down push-buttons are operated
simultaneously. See 6.13
Each time the total display is reset to zero, the
grand total is transferred to permanent
memory.
3.5 Zones, gas groups and T rating
The BA344D has been issued with an EC Type
Examination certificate confirming that it
complies with the requirements for Group II
Category 1 G EEx ia IIC T5 (Tamb –40 to
50
o
C) specified in the ATEX Directive. When
connected to a suitable system the BA344D
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
+50
o
C.
Note : the guaranteed operating temperature
range is –20 to +50
o
C
This allows the BA344D to be installed in all
Zones and to be used with most common
industrial gases.
3.6 Certification Label Information
The certification label is fitted in a recess on
the top outer surface of the enclosure. It
shows the ATEX certification information plus
BEKA associates name and location. Non
European certification information may also be
included. The serial number and date of
manufacture are recorded on a separate label
inside the terminal compartment.