BEKA BA374NG User manual

Issue: 3
5th March 2018
BA374NG
Ex nA and Ex tc
Two input
Timer or Clock
Issue 3

2
1. DESCRIPTION
2. CERTIFICATION
2.1 ATEX Ex nA certification
2.2 Zones, gas groups and T rating
2.3 Safety parameters
2.4 Special conditions for safe use
2.5 Power supply
2.6 Input terminals
2.7 Remote reset terminals
2.8 Status output
2.9 Optional control outputs
2.10 Certification label information
3. SYSTEM DESIGN FOR HAZARDOUS AREAS
3.1 Power supply
3.2 Sensor input
3.2.1 Input switching thresholds
3.2.2 Switch contact input
3.2.3 Open collector input
3.2.4 2-wire proximity detector input
3.2.5 Magnetic pick-off input
3.2.6 Voltage pulse input
3.2.7 Remote reset
3.2.8 Status output
3.2.9 Control outputs - optional
4. INSTALLATION
4.1 Location
4.2 Installation procedure
4.3 EMC
4.4 Units of measurements and tag marking
on scale card.
5. ACCESSORIES
5.1 Display backlight
5.2 Control outputs
5.3 Scale card
5.4 Legend plate
5.5 BA393G pipe mountingkit
5.6 BA394G panel mounting kit
6. OPERATION AS A TIMER
6.1 Initialisation
6.2 Controls when configured as a Timer
6.3 Displays when configured as a Timer
6.4 Timer structure
6.5 Configuration as a Timer
6.5.1 Accessing configuration functions
6.5.2 Summary of Timer configuration
functions
6.5.3 Instrument function: FunCtion
6.5.4 Input A: inPut-A
6.5.5 Input type: inP .TYPE
6.5.6 Debounce: debounce
6.5.7 Input b: inPut-b
6.4.8 Lower display: di5P-2
6.5.9 Starting & stopping the Timer:
5tAr5toP
6.5.10 Units of display: unit5
6.5.11 Set time: 5Et t
6.5.12 Repeat timing cycle: CYCLE5
6.5.13 Cycle function enable: EnbL
6.5.14 Cycle count: cycl cnt
6.5.15 Restart delay: r5t dela
6.5.16 Adjusting the set time 5Et t from
the display mode: AC5Et t
6.5.17 Direction of count: uP or dn
6.5.18 Power fail: p-fail
6.5.19 Local reset: LoC rEt
6.5.20 Local total reset: rE5Et .enbl
6.5.21 Local grand total reset: Glr Gtot
6.5.22 External reset: e-r5et
6.5.23 Status output: 5tat
6.5.24 Status output enable: EnbL
6.5.25 Status output on at: 5tat on
6.5.26 Status output off at: 5tat oFF
6.5.27 Status on delay time: 5tatdELA
6.5.28 Control output 1: oP1
6.5.29 Control output enable: EnbL
6.5.30 Control output on at: oP1 on
6.5.31 Control output off at: oP1 oFF
6.5.32 Output on delay time: oP1 dELA
6.5.33 Control output 2: oP2
6.5.34 Reset grand total from within the
configuration menu: Clr Gtot
6.5.35 Security code: CodE
6.5.36 Reset configuration to factory
defaults r5Et dEF
CONTENTS
The BA374NG is CE marked to show compliance with the European Explosive Atmospheres Directive
2014/34/EU and the European EMC Directive 2014/30/EU

3
7. TIMER APPLICATION EXAMPLES
7.1 Measuring the time that a contact is closed
7.2 Controlling a solenoid valve
7.3 Cycling a solenoid valve
8 MAINTENANCE when configured as a Timer
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. OPERATION AS A CLOCK
9.1 Initialisation and loss of power
9.2 Controls when configured as a clock
9.3 Displays when configured as a clock
9.4 Configuration as a clock
9.4.1 Accessing configuration functions
9.4.2 Summary of Clock configuration
functions
9.4.3 Instrument function: FunCtion
9.4.4 Display format: di5PLAY
9.4.5 Set clock display time: 5et
9.4.6 Enter synchronising time: 5YnC t
9.4.7 Status output: 5tat
9.4.8 Enable status output: enbl
9.4.9 Status output onand off times:
5tat:on 1; 5tat:off 1
5tat:on 2; 5tat:off 2
9.4.10 Control output 1: oP1
9.4.11 Enable Control output 1: EnbL
9.4.12 Control output 1 onand off times:
oP 1 :on 1; oP 1 :off 1
oP 1 :on 2; oP 1 :off 2
9.4.13 Control output 2: oP2
9.4.14 Enable control output 2: EnbL
9.4.15 Control output 2 onand off times:
oP2 :on 1; oP2 :off 1
oP2 :on 2; oP2 :off 2
9.4.16 Access on & off times from display
mode: AC5P
9.4.17 Security code: CodE
9.4.18 Reset configuration to factory
defaults r5Et dEF
10. CLOCK CONFIGRATION EXAMPLE
10.1 Configuration procedure
11. MAINTENANCE when configured as a clock
11.1 Fault finding during commissioning
11.2 Fault finding after commissioning
11.3 Servicing
11.4 Routine maintenance
11.5 Guarantee
11.6 Customer comments
Appendix 1
ATEX dust certification
Appendix 2
IECEx certification
Appendix 3
ETL and cETL certification

4
1. DESCRIPTION
The BA374NG is an Ex nA and Ex tc certified, field
mounting instrument with two inputs that can be
configured on-site as a Timer or as a Clock.
As a Timer the BA374NG can measure and display
the elapsed time between external events, or control
external events via the status output or the optional
control outputs.
When configured as a Clock, the BA374NG can
display time in a variety of formats and the optional
control outputs may be configured to turn on and off
at pre-set times.
This instruction manual is divided into three
sections.
Common features
2. Certification
3. System design for hazardous areas
4. Installations
5. Accessories
Timer
6. Operation as a timer
7. Timer application example
8. Maintenance
Clock
9. Operation as a clock
10. Clock configuration example
11. Maintenance
The BA374NG has been ATEX certified Ex nA and
Ex tc by Notified Body Intertek Testing and
Certification Ltd and complies with the European
ATEX Directive 2014/34/EU.
The main sections of this manual describe ATEX
Ex nA gas certification. See Appendix 1 for details
of the BA374NG ATEX Ex tc dust certification.
For international applications the BA374NG also has
IECEx certification which is described in
Appendix 2.
For applications in the USA and Canada the
BA374NG has ETL and cETL certification which is
described in Appendix 3.
This instruction manual supplements the
abbreviated instruction sheet supplied with each
instrument.

5
2. CERTIFICATION
The BA374NG has ATEX and IECEx Ex nA gas and
Ex tc dust certification. The main sections of this
instruction manual describes ATEX gas certification.
ATEX dust certification is described in Appendix 1
and IECEx gas and dust certification in Appendix 2.
For applications in the USA and Canada the
BA374NG also has ETL and cETL which are
described Appendix 3.
The certification of the BA374NG is unaffected by
whether it is configured as a Timer or as a Clock.
2.1 ATEX Ex nA certification
Notified Body Intertek Testing and Certification Ltd
have issued the BA374NG with a Type Examination
Certificate number ITS16ATEX48409X. This has
been used to confirm compliance with the European
ATEX Directive for Group II, Category 3G
equipment. The instrument carries the Community
Mark and, subject to local codes of practice, may be
installed in any of the European Economic Area
(EEA) member countries and in the EEA EFTA
states, Iceland, Liechtenstein and Norway. ATEX
certificates are also acceptable in Switzerland and
Turkey. The European Commission's Blue Guide
lists the member states, overseas countries and
territories that have adopted harmonisation
legislation.
This section of the instruction manual describes
ATEX Ex nA installations in explosive gas
atmospheres conforming with EN 60079-14
Electrical installations design, selection and erection.
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 Timer or Clock has been certified as Group II
Category 3G Ex ic nA IIC T5 Gc, Ta = -40 to +60°C
apparatus. This is non-sparking apparatus
complying with EN 60079-15 Equipment protection
by type of protection 'n' that minimises the risk of
arcs or sparks capable of creating an ignition hazard
occurring during conditions of normal operation.
The Timer or Clock's front panel push button
contacts are non incendive and have been certified
intrinsically safe Ex ic as shown on the Type
Examination Certificate. This allows the Timer or
Clock to be adjusted and configured live when
installed in Zone 2.
When connected to a suitable system the BA374NG
Timer or Clock may be installed in:
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
In gases that may safely be used with equipment
having a temperature classification of:
T1 450oC
T2 300oC
T3 200oC
T4 135oC
T5 100oC
At ambient temperatures between -40 and +60oC.
This allows use with all commonly used industrial
gases except carbon disulphide CS2.
2.3 Safety parameters
The certificate specifies input safety parameters in
normal operation i.e. without faults for all the
instrument terminals. Where only a voltage or only
a current is specified, the unspecified parameter will
be defined by components within the BA374NG.
2.4 Special conditions for safe use
The Ex nA certificate has an ‘X’ suffix indicating that
the certificate defines special conditions for safe
use. These state that the BA374NG Timer or Clock
should be:
a. Supplied from a limited energy circuit with
output parameters in normal operation equal
to, or less than the instrument’s input
parameters. The certificate states that It is
not necessary to power the instrument from
an intrinsically safe interface, such as a
certified shunt diode safety barrier or a
galvanic isolator to comply with this
requirement.
b. Fitted with cable entry glands or conduit
fittings which maintain the impact and ingress
protection of the enclosure. Certified Ex e or
Ex n components satisfy these requirements.
The BA374NG is supplied fitted with one
certified M20 stopping plug and one
temporary hole plug which should be replaced
with the required gland or conduit fitting.

6
2.5 Power supply
The input safety parameters for the power supply
terminals 1 and 2 are:
Ui = 30V dc
Ii = 100mA
This allows the BA374NG to be powered from any
dc supply which in normal operation has an output
of less 30V and 100mA. See section 4.1 for power
supply recommendations.
2.6 Input terminals
When configured as a Timer the BA374NG is
controlled via input A and input b which may be
individually configured for use with different type of
sensors. Each input is a separate Ex nA circuit,
although the negative side of each input is internally
connected to the negative side of the power supply
and reset terminal RS2. See Fig 10. The two inputs
should not be connected in parallel.
Some types of sensor that may be connected to the
BA374NG inputs, such as a switch contact, open
collector or a 2-wire proximity detector, require
energising to determine their state. For sensors
requiring energising fitting an external link between
terminals 3 and 4 of the BA374NG for input A and
between terminals 7 and 8 for input b, connects an
internal 7V, 6mA supply to the respective input.
Energising is not required when a BA374NG input is
connected to a voltage pulse source.
Fitting an energising link changes the safety
parameters of each BA374NG input as shown in the
following table which also shows the types of sensor
requiring energising (link fitting).
Safety parameters
Input Output
Type of input Link *Ui Uo Io
Switch contact Yes 15V 10.5V 9.2mA
Proximity detector Yes 15V 10.5V 9.2mA
Open collector Yes 15V 10.5V 9.2mA
Magnetic pick-off No 30V 1.1V 0.5mA
Voltage input (low) No 30V 1.1V 0.5mA
Voltage input (high) No 30V 1.1V 0.5mA
*For input A link terminals 3 and 4
*For input b link terminals 7 and 8
2.7 Remote reset terminals
The BA374NG total display my be reset by
connecting the external reset terminals RS1 and
RS2 together for more than one second. The two
reset terminals have the following safety parameters
in normal operation:
Ui = 30V
Uo = 3.8V
Io = 1mA
2.8 Status output
The BA374NG Timer or Clock has an opto-isolated
open collector output which can be configured to
indicate the status of the instrument, or to perform
simple control functions.
The status output is a separate Ex nA circuit with the
following input safety parameters:
Ui = 30V dc
Ii = 100mA
This allows the status output to be connected to any
dc circuit providing that in normal operation the
maximum supply voltage is not greater than 30V dc
and the current is not greater than 100mA.
2.9 Certification label information
The Timer or Clock certification information label is
fitted in a recess on the top outer surface of the
instrument enclosure. It shows the ATEX and IECEx
certification information plus BEKA associates name,
location, year of manufacture and the instrument
serial number.
BA374NG Certification information label

7
3. SYSTEM DESIGN FOR HAZARDOUS
AREAS.
When correctly installed in Zone 2 the BA374NG
Timer or Clock may be connected to almost any
apparatus in the safe area and to Ex n, Ex e, Ex p
and Ex d protected apparatus located in Zone 2.
Because the BA374NG is not certified intrinsically
safe it should not be connected to an intrinsically
safe system.
BEKA Application Guide AG310, Guide for
Installation of [extra low voltage d.c.] Ex nA
instrumentation, which can be downloaded from
www.beka.co.uk, contains explanations and
recommendations for the installation of Ex nA
equipment.
In addition to being able to be connected to other
equipment in the safe area and in Zone 2, the
BA374NG may also be connected to suitably
protected and certified equipment located in Zone 1.
This is illustrated in Fig 6 and explained in
Application Guide AG310.
There are four design requirements:
1. The BA374NG should be powered from a
circuit that has output safety parameters in
normal operation equal to, or less than, the
input safety parameters for terminals 1 and 2
specified by the BA374NG ATEX Type
Examination Certificate.
2. BA374NG input and reset terminals should
only be connected to circuits having safety
parameters in normal operation compliant with
the BA374NG safety parameters which are
specified by the ATEX Type Examination
Certificate.
3. Hazardous area apparatus to which the
BA374NG is connected should be protected by
a technique suitable for the Zone in which the
equipment is located, such as Ex n or Ex e if
located in Zone 2. Equipment protected by
intrinsic safety should not be connected to a
BA374NG.
4. Wiring should comply with Clause 9 of
EN 60079-14.
When designing a system it is important to
remember that terminals 2, 6, 10 and RS2 are
interconnected within the BA374NG. See Fig 10.
3.1 Power supply
The BA374NG Timer or Clock requires a minimum
of 10V between terminal 1 & 2 and consumes:
10mA without optional backlight
plus 6mA when terminals 3 & 4 are linked
plus 6mA when terminals 7 & 8 are linked
plus 16mA with optional backlight
A 24V dc regulated, current limited supply located in
a safe area is suitable.
The power supply should meet the requirements for
personnel safety so that ‘live maintenance’ can
safely be performed. The implicit requirement for
galvanic isolation from the mains supply ensures
that the possible difficulties from circulating earth
currents caused by mains faults is minimised. In
European terms if the power supply is CE marked it
is almost certainly acceptable.
To comply with the requirements of EN 60079:14
Electrical installations design, selection and erection,
each of the wires entering the hazardous area
should be individually fused and contain a means of
isolation. These two requirements may be satisfied
by using DIN rail mounted terminals incorporating
easily removable fuses which can be extracted to
achieve isolation as shown in Fig 1.
If an input current safety parameter Ii is specified, a
suitably rated fuse will ensure that it is not
continuously exceeded in normal operation.
Clear identification of, and easy access to the
means of isolation is essential for their effective use.
It is also necessary to ensure that the maintenance
procedure makes sure that unauthorised re-closure
of the switches does not occur.
It is not considered necessary to have a means of
isolation or electrical protection for the screen.
Fig 1 DIN rail mounting terminals incorporating a
fuse.
For some applications Ex nA instrumentation
energised by a current limited power supply or
instrument that can be switched off, is considered
adequate and to comply with the requirements of the
standard.

8
3.2 Sensor inputs
When configured as a Timer both inputs may be
connected to a wide variety of Zone 2 sensors as
shown in Fig 2, or to safe area sensors as shown in
Fig 3. The two BA374NG inputs are not used when
the instrument is configured as a Clock.
When designing a system it is important to
remember that Terminals 2, 6, 10 and RS2 of the
BA374NG Timer or Clock are internally connected
together.
Fig 2 BA374NG connected to Zone 2 sensors
3.2.1 Input switching thresholds
For reliable operation the BA374NG Timer or Clock
sensor input must fall below the lower threshold and
rise above the upper thresholds shown in the
following table.
Input transducer
Switching thresholds
Lower Upper
Open collector 2k10k
Voltage pulse low 1.0V 3.0V
Voltage pulse high 3.0V 10.0V
Magnetic pick-off 0mV 40mV peak
Proximity detector 1.2mA 2.1mA
Switch 1001000
Switch contact, proximity detector and open collector
sensors require energising which is achieved by
linking Timer or Clock terminals 3 and 4 for input A
and terminals 7 and 8 for input b.
Fig 3 BA374NG connected to safe area sensors
3.2.2 Switch contact input
Any mechanically or magnetically activated switch
contact located in Zone 2 or in the safe area may be
directly connected to pulse input terminals 5 and 6
and to terminals 7 and 8. Both Timer or Clock pulse
inputs are non incendive, allowing connection to
unprotected switch contacts located in Zone 2. The
switch sensor and associated wiring should be able
to withstand a 500V rms insulation test to earth.
Most magnetically activated reed relays comply with
these requirements. The BA374NG contains a
configurable debounce circuit to prevent contact
bounce being counted. See section 6.5.6.
3.2.3 Open collector input
Sensors with an open collector output located in
Zone 2 or in the safe area may be directly connected
to input terminals 5 and 6 or to 7 and 8 providing the
Sensor and associated wiring can withstand a 500V
rms insulation test to earth.
The BA374NG contains a configurable debounce
circuit to prevent false triggering. See section 6.5.6.

9
3.2.4 2-wire proximity detector input
Most Zone 2 certified NAMUR 2-wire proximity
detectors may be directly connected to a BA374NG
input terminals 5 and 6 or to 7 and 8 providing the
minimum operating voltage of the proximitor is
greater than 7.5V. The proximity detector and the
associated wiring should be able to withstand a
500V rms insulation test to earth.
The BA374NG contains a configurable debounce
circuit to prevent false triggering. See section 6.5.6.
3.2.5 Magnetic pick-off input
Sensors incorporating a magnetic pick-off will
usually have a low level ac voltage output which a
BA374NG Timer or Clock can sense when
configured for a CoiL input. The Timer or Clocks
input terminals may be connected to any Zone 2
certified magnetic pick-off sensor, providing the
output in normal operation is equal to or less than
30V the Timer or Clock's Ui. The sensor and
associated wiring should be able to withstand a
500V rms insulation test to earth.
The BA374NG contains a configurable debounce
circuit to prevent false triggering. See section 6.5.6.
3.2.6 Voltage pulse input
Two voltage pulse input ranges are selectable in the
BA374NG Timer or Clocks configuration menu,
VoLt5 L and VoLt5 H. The Timer or Clocks input
terminals may be connected to any Zone 2 certified
voltage pulse output sensor, providing the output in
normal operation is equal to or less than 30V the
Timer or Clock's Ui. The sensor and associated
wiring should be able to withstand a 500V rms
insulation test to earth.
The BA374NG contains a configurable debounce
circuit to prevent false triggering. See section 6.5.6.
3.2.7 Remote reset
Connecting the external reset terminals RS1 and
RS2 together will reset the BA374NG when
configured as a Timer and synchronise the displayed
time to a preset time when configured as a Clock.
Remote resetting may be accomplished by any
mechanically operated switch located in the same
Zone 2 hazardous area as the instrument providing
the switch and the associated wiring can withstand a
500V rms insulation test to earth.
Fig 2 illustrates how a BA374NG may be reset from
both the safe and the hazardous area.
Note: When used as a Timer the BA374NG may
also be reset from the display mode by operating the
&and *push buttons simultaneously for more
than three seconds. See 6.5.20
3.2.8 Status output
The BA374NG Timer or Clock has an opto-isolated
Ex nA certified open collector output which can be
configured to indicate the status of the instrument, or
to perform simple control functions. The output has
the following electrical parameters:
V max = 30V dc
Imax = 10mA
Ron = 60+ 3V
Roff = 1M
The status output may be connected to any dc
circuit providing that in normal operation the
maximum supply voltage is not greater than 30V dc
and the maximum current is not greater than 10mA.
Providing the BA374NG Timer or Clock is correctly
installed in Zone 2, the status output may be directly
connected to any suitably protected equipment
located in Zone 2 or to equipment located in a safe
area.
Fig 4 shows a BA334NE Timer or Clock installed in
Zone 2 with the status output connected to a safe
area load. The status output flows through R1
resulting in a voltage output of about 20V in the safe
area when the status output is activated..

10
Fig 4 Transferring status output to safe area.
3.2.9 Control outputs (optional)
Each of the two factory fitted optional control outputs
is a galvanically isolated single pole solid state
switch as shown in Fig 5. The outputs are polarised
and current will only flow in one direction. Terminals
A1 and A3 should be connected to the positive side
of the supply.
Ron = less than 5+ 0.7V
Roff = greater than 1M
Note: Because of the series protection diode some
test meters may not detect a closed alarm output.
Fig 5 Equivalent circuit of each control output
Each control output is a separate galvanically
isolated Ex nA circuit with the following input
parameters:
Ui = 30V dc
Ii = 200mA
This allows each control output to switch any dc
circuit providing that in normal operation the
maximum supply voltage is not greater than 30V dc
and the switched current is not greater than 200mA.
Providing that the BA374NG Timer or Clock is
correctly installed in Zone 2 the two control outputs
may be used to switch suitably protected equipment
located in a Zone 1 or 2 hazardous area, or
equipment located in a safe area.
Fig 5 shows a typical application in which a Zone 2
mounted BA374NG configured as a Timer is
measuring the time that a Zone 2 contact is closed.
Control output 1 is switching an Ex e sounder in
Zone 1 and control output 2 is switching a safe area
sounder.
Fig 6 Typical control output application
(Shown without recommended screened cables)

11
4. INSTALLATION
4.1 Location
The BA374NG Timer or Clock is housed in robust
IP66 glass reinforced polyester (GRP) enclosure
incorporating an armoured glass window and
stainless steel fittings making it suitable for exterior
mounting in most industrial on-shore and off-shore
installations. The Timer or Clock should be
positioned where the display is not in continuous
direct sunlight.
Field wiring terminals are located on the rear of the
Timer or Clock assembly as shown in Fig 8.
To ensure electrical continuity between the two
conduit or cable entries, the enclosure back-box is
fitted with a bonding plate which includes an M4
earth stud. The bonding plate may be mounted on
the inside or outside of the enclosure. If the carbon
loaded GRP enclosure is not bolted to an earthed
post or structure, this earth stud should be
connected to a local earth or the plant potential
equalising conductor.
An insulated M4 stud is provided in the bottom right
hand corner of the back-box for interconnecting
cable screens.
The BA374NG Timer or Clock may be pipe mounted
using a BA393G pipe mounting kit..
4.2 Installation Procedure
Fig 7 illustrates the instrument installation
procedure.
A. Remove the Timer or Clock assembly by
unscrewing the four captive 'A' screws.
B. Mount the enclosure back-box on a flat surface
and secure with screws or bolts through the
four 'B' holes. Alternatively use the pipe
mounting kit which is available as an
accessory.
C. Remove the temporary hole plug and install an
appropriate IP and temperature rated M20 x
1.5mm certified cable gland or conduit fitting.
If two entries are required, the supplied IP66
stopping plug should be replaced with an
appropriate IP and temperature rated M20 x
1.5mm certified cable gland or conduit fitting.
D. Connect the field wiring to the terminals as
shown in Fig 8. Replace the instrument
assembly on the back-box and evenly tighten
the four 'A' screws.
Fig 7 BA374NG installation procedure
Fig 8 Dimensions and terminal connections

12
4.3 EMC
The BA374NG complies with the requirements of the
European EMC Directive 2014/30/EU. For specified
immunity all wiring should be in screened twisted
pairs, with the screens earthed at one point in the
safe area.
4.4 Units of measurement and tag marking
on scale card.
The Timer or Clock's units of measurement and tag
information are shown on a scale card which slides
into the instrument.
New Timer or Clocks are supplied with a printed
scale card showing the requested units of
measurement and tag information. If this
information is not supplied when the instrument is
ordered, a blank scale card will be fitted which can
easily be marked on-site with a dry transfer or a
permanent marker. Custom printed scale cards are
available from BEKA associates as an accessory.
To remove the scale card from a Timer or Clock
carefully pull the transparent tab at the rear of the
instrument assembly away from the assembly as
shown in Fig 9a.
Fig 9a Removing scale card
To replace the scale card carefully insert it into the
slot on the right hand side of the input terminals as
shown in Fig 9b. Force should be applied evenly to
both sides of the scale card to prevent it twisting.
The card should be inserted until about 2mm of the
transparent tab remains protruding.
Fig 9b Inserting scale card into the
instrument assembly.

13
5. ACCESSORIES
5.1 Display backlight
The BA374NG Timer or Clock can be supplied with
a factory fitted backlight that produces green
illumination enhancing display contrast and enabling
it to be read at night or in poor lighting conditions.
The backlight is internally powered from the
instrument power supply so no additional wiring is
required, but the supply current increases as shown
below.
BA374NG
configured as Timer
current
consumption
BA374NG Timer or Clock 10mA
Additional for backlight 16mA
Addition with terminals 3 & 4 linked 6mA
Addition with terminals 7 & 8 linked 6mA
---------------
To t al c u rr e n t 3 8 m A m a x
BA374NG
configured as Clock
current
consumption
BA374NG Timer or Clock 10mA
Additional for backlight 16mA
---------------
To t al c u rr e n t 2 6 m A m a x
5.2 Control outputs
Although the dual isolated control outputs are factory
fitted options, they are described in the main body of
this instruction manual as they will be used for the
majority of applications. If control outputs are
required they should be specified when the
instrument is ordered.
5.3 Units of measurement & instrument
identification.
New BA374NG Timer or Clocks are supplied with a
printed scale card showing the units of
measurement and tag information specified when
the instrument was ordered. If this information was
not supplied a blank scale card will be fitted which
can easily be marked with a dry transfer or a
permanent marker on-site.
Custom printed scale cards are available as
accessories and may be easily fitted as shown in
section 4.4 of this manual.
5.4 Legend plate
The BA374NG can also be supplied with a blank or
custom laser engraved stainless steel legend plate -
see Fig 8. The plate, which after installation is
visible from the front of the instrument, is supplied
loose with two fixing screws for securing it to the
rear of the instrument's back-box. This plate can
typically accommodate:
1 row of 5 alphanumeric characters 10mm high
or 1 row of 6 alphanumeric characters 7mm high
or 2 rows of 10 alphanumeric characters 5mm high
5.5 BA393G pipe mounting kit
316 stainless steel pipe mounting kit, attaches a
BA374NG to any vertical or horizontal pipe with an
outside diameter between 40 and 73mm.
5.6 BA394G panel mounting kit
The BA374NG may be panel mounted using a
BA394G stainless steel panel mounting kit. This
secures the BA374NG into a panel aperture and
maintains the ingress protection of the instrument,
but it does not provides an IP66 seal between the
front and rear of the panel in which the BA374NG
Timer or clock is mounted.

14
6. OPERATION AS A TIMER
When configured as a Timer the BA374NG can
measure and display the elapsed time between
external events. The Timer can be started and
stopped by remote sensors, or from the front panel
push buttons.
The addition of optional factory fitted isolated control
outputs allows the Timer to control external events
such as opening a valve for a predetermined time.
Again the Timer can be started and stopped by
remote sensors, or from the front panel push
buttons. Timed events can be repeated using the
CYCLE function which enables the BA374NG Timer to
repeat the timing period up to 99 times, or
continuously, with a configurable delay between
timed periods of up to 100 hours.
The BA374NG may be configured to time-up from
zero to the set time 5Et t, or to time-down from the
set time to zero. Times may be entered and
displayed in hours, minutes or in seconds, or in a
combination of units. Elapsed or remaining time is
continuously displayed and a separate display may
be activated to show the target set time 5Et t.
Throughout the timing cycle the instrument can be
paused and restarted without changing the cycle
time. Resetting is accomplished via the front panel
push buttons or a remote contact.
A grand total time is maintained by the instrument
which can be viewed by operating the front panel
push buttons and reset from the display mode or
from within the configuration menu.
Fig 10 shows a simplified block diagram of the
BA374NG when configured as a Timer. The two
separate inputs A and b can be individually
configured to accept inputs from a wide variety of
sensors. When the sensor requires energising to
detect its state, such as a switch contact, open
collector or a two wire proximity detector, a link
connected between external terminals of the
BA374NG supplies power to the sensor input
terminals.
The optically isolated status control output is a
current sink intended for monitoring the Timer's
status, but may also be used for simple control
applications.
The instrument can be supplied with the following
factory fitted accessories:
Internally powered Backlight
Dual isolated Control Outputs
The optional, factory fitted, dual isolated solid state
control outputs may be independently configured to
be activated in any of the timer's state allowing the
BA374NG Timer to perform a wide variety of tasks.
6.1 Initialisation
Each time power is applied to a BA374NG
initialisation is performed. After a short delay the
following display sequence occurs:
All segments of the display are activated
BA374NG is ready to start functioning using
the configuration information stored in the
instrument's permanent memory.
Fig 10 BA374NG block diagram with Timer
configuration.

15
6.2 Controls when configured as a Timer
The BA374NG is controlled and configured via four
front panel push buttons. In the display mode i.e.
when the instrument is timing the push button
functions are:
Push Button Functions
&When local control is enabled starts
the Timer. See 6.5.9
*When local control is enables stops
the Timer. See 6.5.9
) +* Shows the grand total (run time) in
hours and tenths of an hour
irrespective of Timer configuration.
If buttons are held for longer than
ten seconds the grand total may be
reset to zero if the grand total reset
sub-function Glr gtot is enabled in
the LoC r5Et configuration function.
See 6.5.21
The grand total can be reset to zero
from the display mode by pressing
the ) and * buttons
simultaneously for ten seconds until
CLr.no is displayed. Changing the
display to CLr.YE5 .using the &or
*button and then pressing )
will reset the grand total to zero.
& +* Resets the Timer to zero or to the
set time 5Et t depending on
whether the Timer is configured to
time-up or time-down when the two
buttons are operated
simultaneously for more than two
seconds. This is a configurable
function. See 6.5.20
( +* When enabled in the configuration
menu, operating these two buttons
simultaneously provides direct
access from the display mode to the
set time 5Et t and, if the repeat
timing cycle is enabled, to the
restart delay r5t dela See 6.5.16
( +& Shows in succession, firmware
version number, instrument function
elap5e and any output accessories
that are fitted:
- A Dual control outputs
- P Status output
(Always fitted)
( +) Accesses the configuration menu
6.3 Displays when configured as a Timer
The BA374NG has two digital displays and
associated annunciators as shown on front cover of
this manual.
Elapsed time The upper display shows the
elapsed time since the Timer
was started when timing-up from
zero and the remaining time
when timing-down from the set
time. Display may be formatted
as hh:mm:ss; hh:mm; mm:ss or
ss.
Lower display The display options available on
the lower display depend on
whether the Timer repeat cycle
function CYCLE5, which can
repeat the timing period up to 99
times with a configurable delay
between periods, is enabled.
CYCLE5 disabled
The lower display shows the set
time 5ET t or the lower display
may be disabled if not required.
See 6.5.8
CYCLE5 enabled
The lower display shows the
total number of repeat cycles
requested together with the
number of the current cycle.
Each operation may be briefly
named at it's start or periodically
throughout the cycle.
Alternatively the lower display
may be disabled if not required.
See 6.5.8
Reset Activated while elapsed time is
annunciator being reset to zero or to the set
time 5ET t.
Status output RTX shown while status output
annunciator is activated.
Grand total Activated when the grand total
annunciator time is being shown on the
upper display.
Control output Shows status of each optional
annunciators control outputs.
1 and 2.

16
6.4 Timer structure
Fig 11 illustrates the Timer structure and function. It
applies when the instrument is measuring the time
between events or is controlling external events.
The circles in Fig 11 represent the five Timer states,
Reset, Running, Restart-delay, Paused and
Complete. The lines between the circles represent
the event required to move the Timer between
states. e.g. to initiate timing the Timer is moved
from the Reset state to the Running state by a start
event. This could be an input signal at input A or
operation of the &button. Similarly, to pause the
Timer while it is timing, the Timer must be moved
from the Running state to the Pause state by a stop
event which could be an input on input b or
operation of the *button.
Reset
In this state the Timer is readied for operation.
The Timer is stopped and loaded with zero for
timing-up or 5Et t for timing-down.
Running
Entered by a start event from the Reset or
Paused states. The Timer times-up to 5et t
or times-down to zero depending upon it's
configuration.
Pause
Entered by a stop event from Running or
Restart-delay. Timer is stopped, a start event
returns the timer to it's previous state.
Restart-delay
Entered automatically from Running. At the
end of the delay time automatically returns to
Running.
Complete
Entered automatically from Running when
there are no more timing cycles to perform.
When the CYCLE5 function is enabled the timing
cycle can be specified to repeat up to 99 times, or
can be configured to repeat continuously.
6.5 Configuration as a Timer
The BA374NG is configured via the four front panel
push buttons. All the configuration functions are
contained in an easy to use intuitive menu that is
shown diagrammatically in Fig 12.
Each menu function is summarised in section 6.5.2
of this manual and each summary includes a
reference to more detailed information.
All new BA374NG instruments are supplied
configured as requested at the time of ordering. If
configuration is not requested, the BA374NG will be
supplied with default Timer configuration as shown
below, but the instrument can easily be re-
configured on-site.
Function Display Default
Access code CodE 0000
Function FunCtion ELAP5E
Input A inPut-A oP .CoL
Input b inPut-b oP .CoL
Debounce (each input) dEbounCE dEFAuLt
Display 2 di5P-2 5td
Start stop 5tAr5toP LoCAL
Units unit5 12 :00 :00
Set time 5Et t 00 :00 :00
Enable repeat cycle CYCLE5 oFF
Access set time from AC5Et t oFF
display mode.
Direction of count uP or dn dn
Recovery from power p-fail idle
supply failure.
Local total reset t-rE5Et on
Local grand total reset Gt-rE5Et oFF
External reset E-r5et 5td
Enable status output enbl off
Enable control output 1*EnbL oFF
Enable control output 2*EnbL oFF
*Optional output

17
6.5.1 Accessing configuration functions
Throughout this manual front panel push buttons are
shown as &, *, (and ). Legends displayed
by the instrument are shown in a seven segment
font just as they appear on the instrument e.g.
inPut-A and Clr Gtot.
Access to the configuration menu is obtained by
operating the (and )push buttons
simultaneously. If the instrument is not protected by
an access security code the first parameter
FunCtion will be displayed.
If a security code other than the default code 0000
has already been entered, the instrument will display
CodE. Press (to clear this prompt and enter the
security code for the instrument using the &or *
push button to adjust the flashing digit and the
(push button to transfer control to the next digit. If
the correct code has been entered pressing )will
cause the first parameter FunCtion to be displayed.
If an incorrect code is entered, or a push button is
not operated within ten seconds, the instrument will
automatically return to the display mode.
All configuration functions and prompts are shown
on the upper eight digit display. Once within the
main configuration menu the required parameter can
be selected by scrolling through the menu using the
&or *push buttons. The Timer configuration
menu is shown diagrammatically in Fig 12.
When returning to the display mode following
reconfiguration, the Timer will display dAtA followed
by 5AVE while the new information is stored in
permanent memory.
When configuring the Timer or clock if a push button
is not operated for a minute, the instrument will
automatically return to the display mode without
saving any configuration changes. Therefore it is
advisable to save configuration changes frequently
to avoid losing any configuration changes.

18
6.5.2 Summary of Timer configuration
functions
This section summarises all the Timer configuration
functions. When read in conjunction with Fig 16 it
provides a quick aid for configuring the Timer. If
more detail is required, each section of this
summary contains a reference to a full description of
the function.
Display Summary of function
FunCtion Instrument function
Defines the function of the instrument.
May be set to:
ELAP5E Timer configuration
CloC Clock configuration
All the entries in this Timer summary
assume that the BA374NG is
configured as a Timer by selecting
ELAP5E.
See section 6.5.3
inPut-A Configuration of Input A
Contains a sub-menu with two sub-
functions:
inP.tYPE Selects input sensor type
dEbounCE Defines input debounce
See section 6.5.4
inP .tYPE
Configures the Timer sensor Input A to
accept one of six types of input:
VoLt5 L Voltage pulse <1 >3V
VoLt5 H Voltage pulse <3 >10V
CoiL Magnetic pick-off
Pr .dEt Proximity detector *
ContACt Switch contact *
oP .CoL Open collector *
*Energise input by linking terminals 3
& 4 for Input A.
See section 6.5.5
dEbounCE
Defines the level of input debounce
applied to the input A to prevent false
counting:
dEFAuLt
HEAVY
LiGHt
See section 6.5.6
Display Summary of function
inPut b Configuration of input-b
As configuration of inPut A
*Energise input by linking terminals
terminals 7 & 8 for Input b.
See section 6.5.7
di5P-2 Lower display
Configures the lower display to show
set time 5Et t or, when the CYCLE5
repeat function is activated, the restart
delay count-down plus the cycle count
number.
With CYCLE5 not enabled:
Select Lower display shows
5td Set time 5et t
oFF Disables lower display.
See section 6.5.8
With CYCLE5 enabled:
Select Lower display shows
5td Cycle counts requested
and counts performed
with time-down shown
during requested delay
period. Brief notification
of timer status i.e. CYCLE
or dELAY at start of each
period.
LAbEL Exactly as 5td but with
periodic notification of
timer status i.e. CYCLE or
dELAY.
oFF Disables lower display.
See section 6.5.8
5tAr5toP Starting and stopping the timer
Defines how the Timer is started and
stopped.
Start Stop
ControL 1 A input high b input high
ControL 2 A input low b input low
ControL 3 A input high A input low
ControL 4 A input low A input high
LoCAL & button *button
High and low inputs are specified for a
voltage input. For other types of
sensor input, see section 6.5.9

19
Display Summary of function
unit5 Units of display
Enables the format of the displayed
time to be selected.
12 :00 :00 Hours, minutes & seconds
12 :00 Hours & minutes
30 :00 Minutes & seconds
30 Seconds
Excludes delay of optional control
outputs which is always shown in
seconds and the grand total which is
always shown in hours.
See section 6.5.10
5Et t Set time
This is the BA374NG Timer's setpoint.
When controlling an external event via
the optional control outputs the
BA374NG will time-down from the set
time to zero or time-up from zero to the
set time.
Note: Timer will only start if a non zero
value is entered for set time 5et t.
See section 6.5.11
CYCLE5 Repeat timing cycle
Contains a sub-menu with three
sub-functions, EnbL, CYCL Cnt and
r5t dELA.
See section 6.5.12
Cycle function enable EnbL
Enables or disables the cycles function
without changing the parameters.
See section 6.5.13
Cycle count CYCL Cnt
Defines the number of times that the
timer cycle is repeated.
See section 6.5.14
Restart delay r5t dELA
Defines the time delay between timer
cycles.
See section 6.5.15
AC5Et t Access 5Et t from display mode
Contains two sub-functions, EnbL
which when activated allows the set
time 5Et t and restart delay r5t dela
to be adjusted from the display mode.
The second sub-function ACCd defines
a separate access code to protect
access to 5Et t from the display mode.
See section 6.5.16
Display Summary of function
uP or dn Direction of count
Defines whether the Timer times-up
from zero to the set time 5Et t, or
times-down from 5Et t to zero.
See section 6.5.17
P-FAiL Power Failure
Defines how the Timer functions when
power is restored after a power failure.
Contains three alternative options
idle, Pau5E and continue.
Idle Idle
Timer returns in stopped state as if
having completed single timing cycle
displaying Timer value when power
was lost. Timing resumes when reset
followed by start instructions are
received.
Pause pau5e
Timer returns in paused state
displaying Timer value when power
was lost. Timing resumes when start
instruction is received.
Continue continue
Timer will continue without any manual
intervention.
See section 6.5.18
LoC r5Et Local reset
Contains two sub-functions which
when enabled allow the Timer and the
grand total, which represents total
Timer run-time, to be reset to zero via
the front panel push buttons while the
Timer is in the display mode.
See section 6.5.19
Local total reset r5Et .EnbL
When on is selected, Timer is reset to
zero, or 5et t if timing-down, when the
&and *buttons are operated
simultaneously for more than 2
seconds in the display mode.
See section 6.5.20
Local grand total reset CLr Gtot
When on is selected the grand total,
which represents total run-time, may
be reset to zero by operating the
)and *buttons simultaneously for
more than 10 seconds in the display
mode.
See section 6.5.21

20
Display Summary of function
e-r5et External reset
Defines the time taken for closure of
external contacts connected to
terminals RS1 & RS2 to reset the
Timer.
5td 1s
fa5t 2ms
See section 6.5.22
5tat op Status output
Contains sub-menu with four sub-
functions, EnbL, 5tat on, 5tat oFF and
5tat.dELA
Note: Output is a passive open
collector.
See section 6.5.23
Status output enable EnbL
Enables or disables the status output
without changing any of the
parameters.
See section 6.5.24
Status output on 5tat on
Status output turns on when the Timer
enters the state selected in this
function. Output phase can be
reversed.
See section 6.5.25
Status output off 5tat oFF
Status output turns off when the Timer
enters the state selected in this
function. Output phase can be
reversed.
See section 6.5.26
Status on delay 5tat.dELA
Introduces a specified delay between
the on condition occurring and the
status output being activated.
See section 6.5.27
oP1 Control output 1 (Optional)
Contains sub-menu with four sub-
functions, EnbL, oP1 on, oP1 oFF and
oP1 dELA.
See section 6.5.28
Control output enable EnbL
Enables or disables control output 1
without changing the parameters.
See section 6.5.29
Display Summary of function
Control output 1 on oP1 on
Control output 1 turns on when the
Timer enters the state selected in this
function. Output phase can be
reversed.
See section 6.5.30
Control output 1 off oP1 oFF
Control output 1 turns off when the
Timer enters the state selected in this
function. Output phase can be
reversed.
See section 6.5.31
Control output on delay oP1 dELA
Introduces a specified delay between
the on condition occurring and control
output 1 closing.
See section 6.5.32
oP2 Control output 2 (Optional) op2
Functions as control output 1.
See section 6.5.28 to 6.5.33
CLr Gtot Resets grand total to zero
This function resets the grand total,
which represents the total Timer run-
time, from within the configuration
menu when CLr YE5 is selected and
5urE is entered to confirm the
instruction.
Note: Once reset, the grand total can
not be recovered.
See section 6.5.34
CodE Security code
Defines a four digit alphanumeric code
that must be entered to gain access to
the instrument's configuration menu.
Default code 0000 disables the security
function and allows unrestricted access
to all configuration functions when the
(and )buttons are operated
simultaneously in the display mode.
See section 6.5.35
r5Et dEF Reset to factory defaults
Resets the BA374NG to the Timer
factory default configuration shown in
section 6.4 Instruction confirmed by
entering 5urE.
See section 6.5.36