BEKA BA354D User manual

Issue: 5
16th September 2008
BA354D
Intrinsically safe
4/20mA loop-powered
field mounting
rate totaliser
issue 5

2
1. Description
2. Operation
2.1 Controls
2.2 Displays
3. Intrinsic Safety Certification
3.1 ATEX certificate
3.2 4/20mA input
3.3 Reset terminals
3.4 Zones, gas groups & T rating
3.5 Certification label information
4. System Design for Hazardous Areas
ATEX certification
4.1 Flow transmitter loops
4.2 Remote indication
4.3 Resetting the total display to zero
5. Installation
5.1 Location
5.2 Installation procedure
5.3 EMC
6. Programming and Calibration
6.1 Calibration structure
6.2 Accessing programme functions
6.3 Summary of programmable
functions.
6.4 Root extractor
6.5 Resolution
6.6 Position of the decimal points
6.7 Calibration of rate display using an
external current source.
6.8 Calibration of rate display using
internal references.
6.9 Conditioning sub-menu
6.9.1 AC rejection
6.9.2 Calibration of internal
references.
6.10 Resetting grand total
6.11 Timebase
6.12 Function of the Ppush-button
6.13 Total scale factor
6.14 Percentage clip-off
6.15 Local reset of total display
6.16 Security code
6.17 Over and under-range
7. Calibration Examples
7.1 Using an external current source
7.2 Using the internal references
8. Maintenance
8.1 Fault finding during commissioning
8.2 Fault finding after commissioning
8.3 Servicing
8.4 Routine maintenance
8.5 Guarantee
8.6 Customer comments
9. Accessories
9.1 Units of measurement and
instrument identification.
9.2 Alarms
9.2.1 Solid state output
9.2.2 Intrinsic safety
9.2.3 Programming and
adjustment
9.2.4 Alarm enable
9.2.5 Type of alarm
9.2.6 Setpoint adjustment
9.2.7 Alarm function
9.2.8 Alarm output status
9.2.9 Hysteresis
9.2.10 Alarm delay
9.2.11 Alarm silence time
9.2.12 Access setpoint
9.2.13 Adjusting alarm setpoints
from display mode.
9.3 Display backlight
9.4 External push-buttons
9.5 Pipe mounting kits
9.6 Stem mounting kit
10. Index
Appendix 1
ATEX dust certification
CONTENTS
The BA354D is CE marked to show compliance with the
European Explosive Atmospheres Directive 94/9/EC
and the European EMC Directive 2004/108/EC

3
1. DESCRIPTION
The BA354D is an intrinsically safe 4/20mA loop-
powered rate totaliser primarily intended for use
with flowmeters. The instrument simultaneously
displays the rate of flow and the total flow in
engineering units on two separate displays. The
BA354D only introduces a 1.1V drop which allows
it to be installed into almost any 4/20mA flow loop.
No additional power supply or battery is required.
The BA354D has been certified intrinsically safe by
European Notified Body Intertek Testing Sevices
(ITS) to the ATEX Directive 94/9/EC for use in
explosive gas and combustible dust atmospheres.
The EC-Type Examination Certificate specifies that
under fault conditions the voltage, current and
power at input terminals 1 and 3 will not exceed
those specified for simple apparatus in Clause 5.4
of EN50020:1994.
ATEX dust certification is an option – See
Appendix 1.
Housed in a robust IP66 glass reinforced polyester
(GRP) enclosure with an armoured glass window,
the BA354D is surface mounting, or may be pipe
mounted using one of the accessory kits. A stem
mounting kit is also available allowing direct
mounting onto a flowmeter conduit entry.
2. OPERATION
Fig 1 shows a simplified block diagram of a
BA354D. The 4/20mA input current flows through
resistor R1 and forward biased diode D1. The
voltage developed across D1, which is relatively
constant, is multiplied by a switch mode power
supply and used to power the instrument. The
voltage developed across R1, which is proportional
to the 4/20mA input current, provides the input
signal for the analogue to digital converter.
Each time a 4/20mA current is applied to the
instrument, initialisation is performed. After a short
delay the following display sequence occurs:
All segments of the display are activated for
about 3 seconds.
Decimal points on large display are
sequentially activated for about 3
seconds.
Rate display and totaliser start to
function using calibration information
stored in the instrument's permanent
memory.
If the 4/20mA current is disconnected during
operation the latest total and grand total are stored
in permanent memory.
Fig 1 Simplified block diagram of BA354D
2.1 Controls
The BA354D is controlled and calibrated via four
push-button switches which are located behind the
instrument control cover, or as an option on the
outside of the instrument cover. In the operating
mode i.e. when the instrument is displaying rate
and total flow the switch functions are:
Summary of Switch Functions
PDisplays input current in mA or as a
percentage of span.
Down Shows rate display calibration at 4mA
input
Up Shows rate display calibration at
20mA input
E+Down Grand total –
displays least significant 8 digits
E+Up Grand total –
displays most significant 8 digits.
Down Resets total display
+Up programmable function
Note: When optional alarms are fitted the push-
buttons may be programmed to have alternative
functions – see section 9.2

4
Full Description of Switch Functions
PWhile this button is pushed the rate
display will show the input current in
mA, or as a percentage of the
instrument span depending upon how
the instrument has been programmed.
When the button is released the normal
display in engineering units will return.
The function of this push-button may be
modified when alarms are fitted to the
instrument.
Down While this button is pushed the
instrument will show the calibrated rate
display with 4mA input - usually zero for
flow applications. When the button is
released the flow rate will again be
displayed.
Up While this button is pushed the
instrument will show the calibrated rate
display with 20mA input. When the
button is released the flow rate will
again be displayed.
E+ Down While these buttons are pushed the
total display will show the least
significant eight digits of the grand total,
and the grand total annunciator will be
activated.
E+Up While these two buttons are pushed the
total display will show the most
significant eight digits of the grand total
and the grand total annunciator will be
activated.
Down Resets the total display to zero
+Up when these two push-buttons are
operated simultaneously.
Selectable function from programme
menu.
See section 6.15
2.2 Displays
The BA354D has two digital displays and
associated annunciators, plus a flow indicator as
shown on page 1.
Rate Shows the flow rate on the smaller
Display five digit display.
Total Shows the total flow on the larger
display eight digit display. Is set to zero when
reset is operated.
Flow This disc in the lower left hand
indicator corner of the display 'rotates' when the
input current exceeds 4mA.
INTRINSIC SAFETY CERTIFICATION
3.1 ATEX certificate
The BA354D has been issued with an EC-Type
Examination Certificate by Notified Body ITS
Intertek Testing and Certification confirming
compliance with the European ATEX Directive
94/9/EC for Group II, Category 1, gas and dust
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. ATEX certificates are also acceptable
for installations in Switzerland.
This manual describes installations in explosive
gas atmospheres which conform with BS
EN60079:Part14:2003 Electrical Installation in
Hazardous Areas. When designing systems for
installation outside the UK, the local Code of
Practice should be consulted.
For the use in the presence of combustible dust,
please refer to Appendix 1 which describes
installations complying with BS EN 50281-1-
2:1999. Please note that dust certification is an
option which must be specified when the
instrument is ordered.
3.2 4/20mA input
In Europe, sources of energy which do not
generate more than 1.5V; 100mA and 25mW are,
for intrinsic safety purposes, considered to be
simple apparatus (Clause 5.4 of EN50 020:1994).
Although the BA354D indicator does not itself
comply with the requirements for simple apparatus,
the EC-Type Examination Certificate specifies that
under fault conditions the voltage, current and
power at the 4/20mA input terminals 1 and 3 will
not exceed those specified for simple apparatus in
Clause 5.4 of EN50020:1994. This allows the
BA354D 4/20mA input terminals to be connected
into any intrinsically safe circuit protected by a
Zener barrier or galvanic isolator without the need
for additional certification, providing the output
parameters of the circuit do not exceed:
Uo 30V dc
Io 200mA dc
Po 0.85W
The BA354D EC-Type Examination Certificate
specifies that the maximum equivalent capacitance
and inductance between the two 4/20mA input
terminals 1 and 3 is:
Ci 20nF
Li 10µH

5
To determine the maximum permissible cable
parameters these figures must be subtracted from
the maximum cable capacitance and inductance
permitted by the system certificate of the loop into
which the BA354D is connected.
3.3 Reset terminals
The BA354D total display may be reset to zero by
connecting the reset terminals RS1 and RS2
together. These two terminals have the following
output and input safety parameters:
Uo 5V dc
Io 1.3mA dc
Po 1.6mW
Ui 28V dc
Ii 98mA dc
Pi 0.65W
The maximum equivalent capacitance and
inductance between them is:
Ci 1.2nF
Li 0µH
The total display may be reset to zero from within
the hazardous area by any mechanically operated
switch connected directly to terminals RS1 and
RS2. Alternatively, the BA354D may be
programmed so that the total display is reset to
zero when the Up and Down push-buttons are
operated simultaneously.
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. The BA354D system certificates define
suitable interface devices together with the
maximum permissible cable parameters. Almost
any intrinsically safe relay with certification
permitting the contacts to be connected to
equipment in the hazardous area may be used.
Alternatively, one of the positive diode return Zener
barriers listed in the system certificate may be
used - see Fig 3A.
3.4 Zones, gas groups and T rating
The BA354D 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 60oC) specified in the
ATEX Directive. When connected to a suitable
system the BA354D 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°C.
Note: the guaranteed operating temperature range
is –20 to +60°C
This allows the BA354D to be installed in all Zones
and to be used with most common industrial
gases.
3.5 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
instrument serial number and date of manufacture
are recorded on a separate label inside the
terminal compartment.

6
4. SYSTEM DESIGN FOR HAZARDOUS AREA
4.1 Flow transmitter loops
A BA354D rate totaliser may be connected in
series with almost any intrinsically safe 4/20mA
flow loop and calibrated to display the rate of flow
and total flow. There are two basic design
requirements:
1. The intrinsic safety output parameters of the
4/20mA loop, which are defined by the Zener
barrier or galvanic isolator, must be less
than:
Uo 30V dc
Io 200mA dc
Po 0.85W
2. The loop must be able to tolerate the
additional 1.1V required to operate the
indicator.
Fig 2 illustrates an application in which a BA354D
indicator is connected in series with a 2-wire flow
transmitter protected by a Zener barrier.
Fig 2 BA354D in a flow loop
4.2 Remote indication
A BA354D may be driven via an intrinsically safe
interface from a 4/20mA safe area signal to
provide a remote indication of rate and total flow
within a hazardous area. The type of interface is
not critical, either a Zener barrier or a galvanic
isolator may be used, providing that Uo, Io and Po
are not exceeded.
If one side of the 4/20mA current loop may be
earthed, a single channel Zener barrier provides
the lowest cost protection. If the 4/20mA signal is
not isolated, then two Zener barriers, a two
channel Zener barrier or a galvanic isolator must
be used.
When the hazard is a IIC gas, and two single
channel Zener barriers or a two channel Zener
barrier are used, only one barrier or channel may
be a 28V 300ohm device. A 10V 50Ωor diode
return barrier may be used for the second channel
to form a safe combination.
Again it is necessary to ensure that the voltage
capability of the 4/20mA signal is sufficient to drive
the indicator plus the voltage drop introduced by
the intrinsically safe interface. Figs 3A, 3B and 3C
show the alternative circuits which may be used.
Fig 3A Simplest circuit with one side of
20mA current loop connected to
earth.
Also shows optional resetting from
safe area.

7
Fig 3B Two Zener barrier channels are
required if the 4/20mA current loop
can't be earthed at the barrier
busbar.
Also shows optional resetting from
hazardous area
Fig 3C Galvanic isolator can be used with any
4/20mA current loop.
4.3 Resetting the total display to zero
The BA354D may be programmed to reset the
total display to zero when the Up and Down
buttons are pushed simultaneously for 2 seconds,
or an external switch located in the safe or the
hazardous area may be used. Fig 3A illustrates
how the total display may be reset from the safe
area via a single channel diode return Zener
barrier. A certified intrinsically safe relay or
certified opto-isolator may also be used.
Fig 3B shows how the total display may be reset to
zero by an external switch in the hazardous area.
The switch must be mechanically operated and
able to withstand a 500V dc insulation test, but no
Zener barrier or galvanic isolator is required.

8
5. INSTALLATION
5.1 Location
The BA354D rate totaliser is housed in a robust
IP66 glass reinforced polyester (GRP) enclosure
incorporating an armoured glass window and
stainless steel fittings. It is suitable for exterior
mounting in most industrial environments,
including off-shore and waste water treatment.
Please consult BEKA associates if high vibration is
anticipated.
The BA354D enclosure is surface mounting.
Accessory kits described in sections 9.5 & 9.6 of
this manual enable the instrument to be mounted
onto a vertical or horizontal pipe, or directly onto a
flowmeter conduit entry.
The field terminals and the two mounting holes are
located in a separate compartment with a sealed
cover allowing the instrument to be installed
without exposing the display assembly.
Terminals 2 and 4 are internally joined and may be
used for linking the return 4/20mA wire - see Fig 2.
Similarly terminals 5 and 6 are internally joined and
may be used for linking the cable screens. The
BA354D earth terminal is connected to the internal
EMC filters. For maximum radio frequency
interference rejection this terminal should be
connected to a local earth, or to a cable screen
which is earthed in the safe area. To prevent
circulating currents, cable screens should only be
earthed at one point in the safe area.
The BA354D enclosure is supplied with a bonding
plate to ensure electrical continuity between the
three conduit / cable entries.
5.2 Installation Procedure
Fig 4 illustrates the instrument installation
procedure.
a. Remove the instrument terminal cover by
unscrewing the two captive 'A' screws.
b. Mount the instrument on a flat surface and
secure with two M6 screws through the 'B'
holes. Alternatively use one of the mounting
kits described in section 9.5
c. Remove the temporary dust seals from the
three cable entries and install the required
glands, conduit fittings or blanking plugs.
Note: the temporary dust seals do not
provide IP66 protection.
d. Connect the field wiring to the terminals as
shown in Fig 5.
e. Replace the instrument terminal cover and
evenly tighten the two 'A' screws.
Fig 4 BA354D installation procedure
5.3 EMC
The BA354D complies with the requirements of
the European EMC Directive 2004/108/EEC. For
specified immunity all wiring should be in
screened twisted pairs, with the screens earthed
in the safe area.
Additional immunity may be obtained by
connecting the BA354D earth terminal to a local
earth, or to a cable screen which is earthed in the
safe area. If this terminal is not connected,
personal and intrinsic safety will not be degraded.

9
Fig 5 Dimensions and terminal connections

10
6. PROGRAMMING & CALIBRATION
The BA354D is programmed and calibrated via
four push-buttons which are located behind the
instrument control cover. If frequent access to
the push-buttons is required, the rate totaliser can
be supplied with duplicate membrane push-buttons
mounted on the outside of the control cover.
All the programming functions are contained in an
easy to use menu which is shown diagramatically
in Figs 7A and 7B. Each function is summarised
in section 6.3 which includes references to more
detailed information. Although this simple menu
driven system enables most adjustments to be
made without repeated reference to this manual, it
is recommended that at least the summary of the
programmable functions in section 6.3 is read
before attempting programming or recalibration.
When the instrument is fitted with alarms, the basic
menu is expanded to include the alarm functions
that are described in section 9.2 of this manual.
Note: While the instrument is being programmed
or calibrated totalisation is suspended, any flow
occurring during this time will not be recorded.
6.1 Calibration structure
Fig 6 shows the BA354D calibration structure. The
4/20mA input current, which in flow applications
represents flow rate, is displayed on the five digit
rate display. Using the instrument 'CAL' or 'SEt'
functions this display may be calibrated to show
the flow rate in engineering units. Both the zero
(display at 4mA) and the span (display at 20mA)
are adjustable, although for flow application the
display at 4mA is usually zero. The position of
the decimal point in the rate display is defined by
the d.p. function. To simplify calibration the
BA354D uses floating point arithmetic, moving the
rate display decimal point position will therefore
affect totalisation.
Fig 6 Calibration structure
The BA354D total display is calculated from the
rate display using two serial factors: the timebase
't-bASE' and the total scaling factor 'SCALE-t'.
The timebase divides the rate display according to
whether the rate display represents flow per
second, per minute or per hour. The total scaling
factor 'SCALE-t' is a wide range programmable
dividing factor allowing the rate and total displays
to be in different units.