BEKA BA377E-SS User manual

Issue: 6
4th May 2021
BA377E-SS
Rugged one input
intrinsi ally safe
Timer or Clo k
Issue 6

2
1. DESCRIPTION
2. INTRINSIC SAFETY CERTIFICATION
2.1 ATEX gas certification
2.2 Zones, gas groups and T rating
2.3 Special conditions for safe use
2.4 Po er supply
2.5 Input terminals
2.5.1 Sensors that do not require
energising.
2.5.2 Sensors that require energising
2.6 Remote reset terminals
2.7 Control outputs - optional
2.8 Certification label information
3. SYSTEM DESIGN FOR HAZARDOUS AREAS
3.1 Use ith Zener barriers
3.1.1 Po er supply
3.1.2 Sensor inputs
3.1.3 S itch contact input
3.1.4 Open collector input
3.1.5 2- ire proximity detector input
3.1.6 Magnetic pick-off input
3.1.7 Voltage input
3.1.8 Remote reset
3.1.9 Control outputs - optional
3.2 Use ith Galvanic Isolators
3.2.1 Po er supply
3.2.2 Sensor inputs
3.2.3 S itch contact input
3.2.4 Open collector input
3.2.5 2- ire proximity detector input
3.2.6 Magnetic pick-off input
3.2.7 Voltage input
3.2.8 Remote reset
3.2.9 Control outputs - optional
3.3 Use in an Ex e or Ex p panel enclosure in
Zone 1 or Zone 2.
3.3.1 Installation in an Ex e panel
enclosure ithin Zone 1 or Zone 2.
3.3.2 Installation in an Ex p panel
enclosure ithin Zone 1 or Zone 2.
4. INSTALLATION
4.1 Location
4.2 Installation procedure
4.3 EMC
4.4 Timer or clock earthing
5.5 Scale card
5. ACCESSORIES
5.1 Display backlight
5.2 Control outputs
5.3 Scale card
5.4 Tag information
5.5 BA495 rear sealing kit
6. OPERATION AS A TIMER
6.1 Initialisation
6.2 Controls hen configured as a Timer
6.3 Displays hen 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: inPut
6.5.5 Input type: inP . tYPE
6.5.6 debounce: debounce
6.5.7 Lo er display: di5P-2
6.5.8 Starting & stopping the Timer:
5tAr5toP
6.5.9 Units of display: unit5
6.5.10 Set time: 5Et t
6.5.11 Repeat timing cycle: CYCLE5
6.5.12 Cycle function enable: EnbL
6.5.13 Cycle count: cycl cnt
6.5.14 Restart delay: r5t dela
6.5.15 Adjusting the set time 5Et t and
restart delay r5t dela from the
display mode: AC5Et t
6.5.16 Direction of count: uP or dn
6.5.17 Po er fail: p fail
6.5.18 Local reset: LoC rEt
6.5.19 Local total reset: rE5Et . enbl
6.5.20 Local grand total reset: clr Gtot
6.5.21 Control output 1 (Optional): oP1
6.5.22 Control output 1 enable: EnbL
6.5.23 Control output on at: oP1 on
6.5.24 Control output off at: oP1 oFF
6.5.25 Output on delay time: oP1 dELA
6.5.26 Control output 2 (Optional): oP2
6.5.27 Reset grand total from ithin the
configuration menu: Clr Gtot
6.5.28 Security code: CodE
6.5.29 Reset configuration to Timer
factory defaults: r5Et dEF
7. TIMER APPLICATION EXAMPLES
7.1 Measuring the time that a contact is closed
7.2 Controlling an IS solenoid valve
CONTENTS
The BA377E-SS is CE marked to sho compliance ith the European Explosive Atmospheres Directive
2014/34/EU and the European EMC Directive 2014/34/EU

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8 MAINTENANCE when onfigured 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 po er
9.2 Controls hen configured as a clock
9.3 Displays hen configured as a clock
9.4 Configration 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 Control output 1 (Optional): oP1
9.4.8 Enable Control output 1: EnbL
9.4.9 On and off times:
oP 1 : on 1; oP 1 : off 1
oP 1 : on 2; oP 1 : off 2
9.4.10 Control output 2 (Optional): oP2
9.4.11 Enable control output 2: EnbL
9.4.12 On and off times:
oP2 : on 1; oP2 : off 1
oP2 : on 2; oP2 : off 2
9.4.13 Access on & off times from display
mode: AC5P
9.4.14 Security code: CodE
9.4.15 Reset configuration to Clock
factory defaults: r5Et dEF
10. CLOCK CONFIGURATION EXAMPLE
10.1 Configuration procedure
11. MAINTENANCE when onfigured as a Clo k
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

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1. DESCRIPTION
The BA377E-SS is a rugged intrinsically safe, panel
mounting instrument ith a single input that can be
configured as a Timer or as a Clock. As a Timer the
BA377E-SS is able to measure and display the
elapsed time bet een external events, or control
external events via t o optional factory fitted control
outputs.
When configured as a Clock, the instrument can
display time in a variety of formats and the t o
optional control outputs may be configured to s itch
loads on and off at pre-set times.
This instruction manual is divided into sections.
Common features
2. Intrinsic safety certification
3. System design for hazardous areas
4. Installations
5. Accessories
Timer
6. Operation as a timer
7. Configuration example
8. Maintenance
Clo k
9. Operation as a clock
10. Configuration example
11. Maintenance
The BA377E-SS has been certified intrinsically safe
for use in gas and dust hazardous areas by Notified
Body Intertek Testing and Certification Ltd and
complies ith the European ATEX Directive 2014/34/
EU. It has a rugged stainless steel enclosure and an
impact resistant glass indo . In addition to normal
intrinsically safe applications, the certification allo s
it to be installed in an Ex e, Ex n, Ex p or Ex t panel
enclosure ithout invalidating the panel enclosure's
certification.
The common features sections of this instruction
manual describe ATEX certification for use in gas
atmospheres. Dust certification is described in
Appendix 1.
For international applications the BA377E-SS has
IECEx certification hich is described in Appendix 2.
This instruction manual supplements the abbreviated
instruction sheet supplied ith each instrument.
2. INTRINSIC SAFETY CERTIFICATION
The BA377E-SS has IECEx and ATEX gas
certification. This section of the instruction manual
describes ATEX gas certification. IECEx and other
approvals are each described in separate
appendixes to this manual. The intrinsic safety of
the instrument is unaffected by hether it is
configured as a Timer or as a Clock.
2.1 ATEX gas ertifi ation
Notified Body Intertek Testing and Certification Ltd
have issued the BA377E-SS ith an EU-Type
Examination Certificate number ITS16ATEX28408X.
This confirms compliance ith harmonised European
standards and it has been used to confirm
compliance ith the European ATEX Directive for
Group II, Category 1G equipment. The Timer or
Clock carries the European 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 S itzerland.
This section of the instruction manual describes
ATEX installations in explosive gas atmospheres
complying ith EN60079-14 Electrical Installation
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 BA377E-SS Timer or Clock has been certified
Ex ia IIC T5 Ga. When connected to a suitable
system it 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
ill only exist for a short time.
In gases that may be used ith equipment having a
temperature classification of:
Group A propane
Group B ethylene
Group C hydrogen
Having a temperature classification of:
T1 450ºC
T2 300ºC
T3 200ºC
T4 135ºC
T5 100ºC

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At ambient temperatures bet een:
-40 to +60oC When installed as an Ex i
intrinsically safe instrument in
an Ex e, Ex n, Ex p or Ex t
enclosure.
-40 to +70oC When used as an Ex i
intrinsically safe instrument
not in an Ex e, Ex n, Ex p or
Ex t enclosure.
2.3 Spe ial onditions for safe use
The ATEX intrinsic safety certificate number has an
‘X’ suffix indicating that for some applications special
conditions apply for safe use.
When installed in an Ex e, Ex n, Ex p or Ex t
panel enclosure all connections to the
BA377E-SS must e made y appropriately
rated Zener arriers or galvanic isolators.
This means that hen installed in an Ex e, Ex n,
Ex p or Ex t panel enclosure the BA377E-SS
remains an intrinsically safe instrument and must
comply ith the installation requirements sho n in
this manual.
The certificate also states:
The front of the stainless steel enclosure
complies with the requirements for Ex e, Ex n
Ex p & Ex t type of protection.
Therefore hen correctly installed the BA377E-SS
Timer or Clock ill not invalidate the Ex e, Ex n, Ex p
or Ex t panel enclosure certification in hich it is
mounted.
Note: At temperatures belo -20°C the
instruments ill continue to function, but the display
response ill become slo er and the contrast ill be
reduced.
2.4 Power supply
When installed in a hazardous area the BA377E-SS
must be po ered via a certified Zener barrier or
galvanic isolator from a dc supply located in the safe
area, or from certified associated apparatus ith an
intrinsically safe output.
The input safety parameters of the BA377E-SS
po er supply terminals 1 and 2 are:
Ui = 28V dc
Ii = 200mA dc
Pi = 0.84W
Any certified Zener barrier or galvanic isolator ith
output safety parameters equal to or less than these
limits may be used to po er the BA377E-SS.
The maximum equivalent capacitance and
inductance bet een terminals 1 and 2 is:
Ci = 2nF
Li = 4µH
To determine the maximum permissible po er
supply cable parameters the above figures, hich
are small and may be ignored for many applications,
should be subtracted from the maximum permitted
parameters, Co and Lo, specified for the Zener
barrier or galvanic isolator po ering the BA377E-
SS.
2.5 Input terminals
When configured as a Timer the BA377E-SS is
controlled via a single input that may be configured
for use ith different types of sensor. The input is a
separate intrinsically safe circuit, although the
negative side is internally connected to the negative
side of the po er supply and the reset terminal RS2.
See Fig 15.
Some types of sensor that may be connected to the
BA377E-SS input, such as a s itch contact or a 2-
ire proximity detector, require energising to
determine their state. For sensors requiring
energising fitting an external link bet een terminals 3
& 4 connects an internal 7V, 6mA supply to the input.
Energising is not required hen the BA377E-SS
input is connected to a voltage input source.
Fitting an energising link changes the output safety
parameters of the BA377E-SS input as sho n in the
follo ing table hich also sho s the types of sensor
requiring energising (link fitting).
Output safety parameters of
input terminals 5 & 6.
Type of input Link* Uo Io Po
S itch contact Yes 10.5V 8.2mA 25mW
Proximity detector Yes 10.5V 8.2mA 25mW
Open collector Yes 10.5V 8.2mA 25mW
Magnetic pick-off No 1V 11µA 3µW
Voltage input (lo ) No 1V 11µA 3µW
Voltage input (high) No 1V 11µA 3µW
*Link terminals 3 and 4

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2.5.1 Sensors that do not require energising
Sensors ith a voltage output do not require
energising, therefore terminals 3 & 4 should not be
linked. When not energised i.e. ithout a link the
BA377E-SS input complies ith the requirements for
simple apparatus. For intrinsic safety purposes,
sources of energy ith output parameters less than
1.5V; 100mA and 25mW are considered to be simple
apparatus (Clause 5.7 of EN60079-11), hich allo s
them not to be considered or documented hen
assessing the safety of an intrinsically safe system,
thus simplifying loop assessment.
This allo s almost any voltage output sensor to be
directly connected to the BA377E-SS input in a
hazardous area providing that:
a. The sensor is a certified intrinsically safe device
having output parameters equal to or less than:
Uo ≤ 28V dc
Io ≤ 200mA dc
Po ≤ 0.84W
or complies ith requirements for
simple apparatus.
b. The sensor and associated iring can
ithstand a 500V rms insulation test to earth.
c. The sensor is located in the same hazardous
area as the BA377E-SS.
The BA377E-SS EC-Type Examination Certificate
specifies that the equivalent capacitance and
inductance of the BA377E-SS sensor input is:
Ci = 2nF
Li = 4µH
To determine the maximum permissible cable
parameters these figures should be subtracted from
the maximum permitted output parameters Lo and
Co specified by the certificate for the sensor
connected to the BA377E-SS input terminals. The
BA377E-SS input parameters are small and
therefore unlikely to make a significant difference to
the allo able cable parameters.
2.5.2 Sensors that require energising
S itch contacts, proximity detectors and open
collector sensors require energising hich is
achieved by linking t o BA377E-SS terminals
together as described in section 2.5. When
energised, the output parameters of the BA377E-SS
input are:
Uo = 10.5V dc
Io = 8.2mA dc
Po = 25mW
These parameters do not comply ith the
requirements for simple apparatus and should be
considered hen assessing the safety of the sensor
connected to a BA377E-SS input.
Any certified intrinsically safe sensor may be
connected to the BA377E-SS energised input
providing that the sensor's input safety parameters
are equal to, or greater than, the output safety
parameters of the BA377E-SS input sho n above.
This is not restrictive and most intrinsically safe
sensors ill comply. A sensor complying ith the
requirements for simple apparatus, such as a
mechanically operated s itch contact, may also be
connected.
This allo s most mechanically operated s itches,
open collector transistors and certified intrinsically
safe NAMUR proximity detectors to be directly
connected to the BA377E-SS energised input. The
sensor and iring should be able to ithstand a
500V rms insulation test to earth and the sensor
should be located in the same hazardous area as the
BA377E-SS.
The BA377E-SS EC-Type Examination Certificate
specifies that the maximum capacitance and
inductance that may be safely connected to the
energised input (link connected) is:
Co = 2.4µF
Lo = 200mH
Again this is not restrictive as the combined
capacitance and inductance of most sensors and
connecting cable ill be less than this.

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2.6 Remote reset terminals
Connecting the external reset terminals RS1 and
RS2 together ill reset the BA377E-SS hen
configured as a Timer and synchronise the displayed
time hen configured as a Clock. The t o reset
terminals have the follo ing input and output safety
parameters:
Uo = 3.8V dc
Io = 1.6mA dc
Po = 2.0mW
Ui = 28V dc
Ii = 200mA dc
Pi = 0.84W
The equivalent capacitance and inductance bet een
them is:
Ci = 0nF
Li = 0µH
The maximum cable capacitance and inductance
that may be safely connected bet een the reset
terminals RS1 and RS2 is:
Co = 40µF
Lo = 1H
The reset terminals may be directly connected to any
mechanically operated s itch located ithin the
same hazardous area as the BA377E-SS. The
s itch and associated iring should be able to
ithstand a 500V insulation test to earth.
If the reset s itch is required in the safe area a
Zener barrier or intrinsically safe relay is required to
transfer the contact closure into the hazardous area.
A diode return barrier is not suitable for this
application. Almost any intrinsically safe relay ith
certification permitting the contacts to be connected
to equipment in the hazardous area may be used.
When used as a Timer the BA377E-SS may also be
reset from the display mode by operating the & and
push buttons simultaneously for more than t o
seconds. See 6.5.19
2.7 Control outputs - optional
Each of the t o factory fitted optional control outputs
is a separate galvanically isolated intrinsically safe
circuit ith output safety parameters complying ith
the requirements for simple apparatus. This allo s
the control output terminals A1 & A2 and A3 & A4 to
be connected to almost any intrinsically safe circuit
protected by a Zener barrier or galvanic isolator
providing the output safety parameters of the circuit
do not exceed:
Uo ≤ 28V dc
Io ≤ 200mA dc
Po ≤ 0.84W
The maximum equivalent capacitance and
inductance bet een each set of control output
terminals is:
Ci = 22nF
Li = 8µH
To determine the maximum permissible cable
capacitance Ci should be subtracted from the
maximum permitted external capacitance Co
specified by the certificate for the intrinsically safe
interface po ering the circuit being s itched by the
control output. See fig 4.

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2.8 Certifi ation label information
The BA377E-SS product certification label is fitted in
a recess on the top outer surface of the enclosure. It
sho s the ATEX and IECEx certification information
plus BEKA associates name and location and the
instrument serial number. Certification information
from other authorities may also be included.
BA377E-SS Certification information label
3. SYSTEM DESIGN FOR HAZARDOUS
AREAS
3.1 Use with Zener barriers
Zener barriers are the least expensive intrinsically
safe interface bet een a safe and hazardous area.
Ho ever, they require a high integrity earth
connection that may be expensive to install and they
do not provide isolation. When a high integrity earth
connection is not already available, it may be less
expensive and complicated to use galvanic isolators
for the installation of a single BA377E-SS.
Terminals 2, 6 and RS2 of the BA377E-SS are
internally connected together as sho n in Fig 15. If
any of these terminals are earthed, as sho n in
Figs 1 & 2, the other common terminals should only
be connected to the same earth, i.e. the barrier
busbar, or to circuits that have at least 500V
insulation to earth.
Any Zener barrier certified for the gas group and
Zone in hich the BA377E-SS is installed may be
used, providing the output parameters do not exceed
the input parameters of the BA377E-SS terminals to
hich it is connected. Only one polarity of Zener
barrier i.e. positive or negative may be used in each
system.
Fig 1 illustrates the basic circuit that is used for all
BA377E-SS Timer installations protected by Zener
barriers. BA377E-SS Clock installations are the
same, except that the input terminals 5 & 6 are not
used. For simplicity the optional control outputs are
described separately in section 3.1.9 of this manual.
Fig 1 BA377E-SS Timer used ith Zener barriers
Alternatively the sensor may be located in the safe
area. Fig 2 sho s ho an additional Zener barrier is
used to transfer signals to the Timer in the
hazardous area.

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When more than one Zener barrier is used in a
system all must have the same polarity. i.e. all
positive or all negative barriers. When designing a
Timer system it is important to remember that
terminals 2, 6 and RS2 of the BA377E-SS are
connected together ithin the instrument. Similarly,
terminals 2 and RS2 are internally connected
together hen the BA377E-SS is configured as a
Clock. See Fig 20.
Fig 2 BA377E-SS Timer used ith Zener barriers
and input sensor in the safe area.
3.1.1 Power supply
The BA377E-SS requires a minimum of 10V
bet een terminal 1 & 2 and consumes:
10mA ithout optional backlight
plus 22mA for optional backlight
plus 6mA hen terminals 3 & 4 are linked
Any Zener barrier certified for the gas group and
Zone in hich the BA377E-SS is installed may be
used to po er the instrument, providing the output
safety parameters of the barrier are equal to or less
than the input safety parameters of terminals 1 & 2.
Although this allo s a ide variety of barriers to be
used, a positive polarity 28V; 93mA; 300 Zener
barrier, hich has an end-to-end resistance of about
340, is an industry standard device hich is
frequently used. With this barrier the supply voltage
in the safe area must be bet een the minimum value
sho n belo and the maximum orking voltage of
the Zener barrier hich, depending upon
manufacturer, ill be approximately 26V.
13.5V min ithout optional backlight
20.9V min ith optional backlight
plus 2.1V hen terminals 3 & 4 are linked
3.1.2 Sensor input
When configured as a Timer the sensor input may be
connected to a ide variety of hazardous area
devices as sho n in Fig 1, or to safe area sensor as
sho n in Fig 2. The input must be maintained not
momentary. The BA377E-SS input is not used hen
the instrument is configured as a Clock.
No Zener barrier is required in series ith the input if
the intrinsically safe sensor is located ithin the
same hazardous area as the BA377E-SS. The
follo ing table sho s the instrument's input
s itching thresholds hen configured to operate ith
various sensors. For reliable operation the BA377E-
SS input must fall belo the lo er threshold and rise
above the upper threshold.
Sensor Swit hing thresholds
Lower Upper
Low voltage range 1.0V 3.0V
High voltage range 3.0V 10.0V
Proximity dete tor 1.2mA 2.1mA
Swit h 1001000
Open olle tor 2k10k
S itch contacts, proximity detectors and open
collector sensors require energising hich is
achieved by linking terminals 3 and 4 together as
described in section 2.5.
3.1.3 Swit h onta t input
Any mechanically activated s itch contact may be
directly connected to input terminals 5 & 6 providing
the s itch is located in the same hazardous area as
the BA377E-SS, and the s itch and associated
iring can ithstand a 500V rms insulation test to
earth. Most industrial push buttons and magnetically
activated reed relays comply ith these
requirements. The BA377E-SS contains a
configurable debounce circuit to prevent false
triggering of the instrument. Three levels of
debounce protection are available. See
section 6.5.6.
3.1.4 Open olle tor input
Any sensor ith an open collector output located in
the same hazardous area as the BA377E-SS, such
as a mechanically activated opto-isolator may be
directly connected to input terminals 5 & 6. The
sensor and the associated iring must be able to
ithstand a 500V rms insulation test to earth. The
BA377E-SS contains a configurable debounce circuit
to prevent false triggering. Three levels of debounce
protection are available. See section 6.5.6.

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3.1.5 2-wire proximity dete tor input
Most intrinsically safe NAMUR 2- ire proximity
detectors may be connected to the BA377E-SS
sensor input, providing the input safety parameters
of the proximity detector are equal to or greater than
the output safety parameters of a BA377E-SS input.
i.e.
Ui ≥ 10.5V dc
Ii ≥ 8.2mA dc
Pi ≥ 25mW
and the minimum operating voltage of the proximity
detector is less than 7.5V. The proximity detector
must be located in the same hazardous area as the
BA377E-SS.
The BA377E-SS contains a configurable debounce
circuit to prevent false triggering of the instrument.
Three levels of debounce protection are available.
See section 6.5.6.
3.1.6 Magneti pi k-off input
CoiL in the input configuration menu is a lo level
voltage input intended for use ith an intrinsically
safe magnetic pick-off sensor hich is not suitable
for controlling a BA377E-SS.
3.1.7 Voltage input
T o voltage input ranges are selectable in the
BA377E-SS Timer configuration menu, VoLt5 L and
VoLt5 H. When configured for either of the voltage
ranges and terminals 3 and 4 are not linked, the
input terminals 5 and 6 comply ith the requirements
for simple apparatus. This allo s the input to be
connected to any certified intrinsically safe voltage
source located ithin the same hazardous area as
the BA377E-SS having output parameters equal to
or less than:
Uo ≤ 28V dc
Io ≤ 200mA dc
Po ≤ 0.84W
The BA377E-SS Timer may therefore be directly
connected to and controlled by most certified
intrinsically safe high level voltage signals.
The maximum permitted cable parameters ill be
defined by the intrinsic safety certification of the
voltage source less the BA377E-SS input
parameters hich are small and can often be
ignored.
The BA377E-SS contains a configurable debounce
circuit to prevent false triggering of the instrument.
Three levels of debounce protection are available.
See section 6.5.6.
3.1.8 Remote reset
Connecting the external reset terminals RS1 and
RS2 together ill reset the BA377E-SS hen
configured as a Timer and synchronise the displayed
time hen configured as a Clock. Remote resetting
may be accomplished by any mechanically operated
s itch located in the same hazardous area as the
instrument providing the s itch and the associated
iring can ithstand a 500V rms insulation test to
earth. No Zener barrier is required.
A BA377E-SS may also be remotely reset from the
safe area. Any s itch may be used but a Zener
barrier is required to transfer the contact closure into
the hazardous area hich may be combined ith the
supply barrier so that only one package is required.
A diode return barrier is not suitable for this
application. Fig 1 illustrates ho a BA377E-SS may
be reset from both the safe and the hazardous area.
Note: When used as a Timer the BA377E-SS may
also be reset from the display mode by operating the
& and push buttons simultaneously for more
than t o seconds. See 6.5.19

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3.1.9 Control outputs (optional)
Each of the t o factory fitted optional control outputs
is a galvanically isolated single pole solid state
s itch as sho n in Fig 3. The outputs are polarised
and current ill only flo in one direction. Terminals
A1 and A3 should be connected to the positive side
of the supply.
Ron < 5 + 0.7V
Roff > 1M
Note: Because of the series protection diode some
test meters may not detect a closed alarm output
Fig 3 Equivalent circuit of each control output
Each control output is a separate galvanically
isolated intrinsically safe circuit ith output safety
parameters complying ith the requirements for
simple apparatus. This allo s the control output
terminals A1 & A2 and A3 & A4 to be connected to
almost any intrinsically safe circuit protected by a
Zener barrier having output parameters equal to or
less than:
Uo ≤ 28V
Io ≤ 200mA
Po ≤ 0.84W
The maximum equivalent capacitance and
inductance bet een each set of control output
terminals is:
Ci = 22nF
Li = 8µH
To determine the maximum permissible cable
parameters Ci and Li of the BA377E-SS should be
subtracted from the maximum permitted external
capacitance Co and inductance Lo specified by the
certificate for the Zener barrier po ering the circuit
as sho n in Fig 4. The internal capacitance and
inductance of other devices in the loop, such as the
solenoid valve in Fig 4, should also be subtracted
from Co & Lo.
Fig 4 Typical control output application

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3.2 Use with Galvani Isolators
Galvanic isolators are probably the simplest
intrinsically safe interface to install as they provide
isolation and do not require a high integrity earth
connection.
Any galvanic isolator certified for the gas group in
hich the BA377E-SS is installed, ith output
parameters less than the input parameters of the
BA377E-SS having the correct function may be
used.
Fig 5 BA377E-SS used ith galvanic isolators
Fig 5 illustrates the basic circuit that is used for all
BA377E-SS installations protected by galvanic
isolators.
Alternatively sensors may be located in the safe
area. Fig 6 sho s ho an additional galvanic
isolator is used to transfer the sensor output to the
BA377E-SS in the hazardous area, although it may
be difficult to find isolators for some types of sensor.
The BA377E-SS input energising link should be fitted
to suite the output of the galvanic isolator not the
sensor.
Fig 6 BA377E-SS Timer used ith galvanic
isolators and input sensor in safe area.
3.2.1 Power supply
The BA377E-SS requires a minimum of 10V
bet een terminal 1 & 2 and consumes:
10mA ithout optional backlight
plus 22mA ith optional backlight
plus 6mA hen terminals 3 & 4 are linked
Any galvanic isolator certified for the gas group and
Zone in hich the BA377E-SS is installed may be
used to po er the instrument. The output safety
parameters of the isolator must be equal to or less
than the input safety parameters of terminals 1 & 2
and the voltage at terminals 1 & 2 must be greater
than 10V. These requirements are not restrictive
and allo a ide range of galvanic isolators, such as
solenoid drivers, to be used.

13
3.2.2 Sensor inputs
As sho n in Fig 5 the BA377E-SS input can be
directly connected to hazardous area sensor, or to
safe area sensors via isolators as sho n in Fig 6.
Galvanic isolators are not required in series ith the
input if the intrinsically safe sensor is located ithin
the same hazardous area as the BA377E-SS. The
input must be maintained not momentary.
The BA377E-SS may be used ith a ide variety of
sensors, the follo ing table sho s the s itching
thresholds for each type. For reliable operation the
input signal must fall belo the lo er threshold and
rise above the upper threshold.
Sensor Swit hing thresholds
Lower Upper
Low voltage range 1.0V 3.0V
High voltage range 3.0V 10.0V
Proximity dete tor 1.2mA 2.1mA
Swit h 1001000
Open olle tor 2k10k
S itch contacts, proximity detectors and open
collector sensors require energising hich is
achieved by linking t o BA377E-SS terminals
together as described in section 2.5.
3.2.3 Swit h onta t input
Any mechanically activated s itch contact may be
directly connected to input terminals 5 & 6 providing
the s itch is located in the same hazardous area as
the BA377E-SS, and the s itch and associated
iring can ithstand a 500V rms insulation test to
earth. Most magnetically activated industrial push
buttons and reed relays comply ith these
requirements. The BA377E-SS contains a
configurable debounce circuit to prevent false
triggering of the instrument. Three levels of
debounce protection are available. See
section 6.5.6
3.2.4 Open olle tor input
Any open collector sensor located in the same
hazardous area as the BA377E-SS, such as a
mechanically activated opto-isolator, may be directly
connected to input terminals 5 & 6. The sensor and
the associated iring must be able to ithstand a
500V rms insulation test to earth.
The BA377E-SS contains a configurable debounce
circuit to prevent false triggering. Three levels of
debounce protection are available See section 6.5.6
3.2.5 2-wire proximity dete tor input
Most intrinsically safe NAMUR 2- ire proximity
detectors may be connected to the BA377E-SS
input, providing the input safety parameters of the
proximity detector are equal to or greater than the
output safety parameters of a BA377E-SS input. i.e.
Ui ≥ 10.5V dc
Ii ≥ 8.2mA dc
Pi ≥ 25mW
and the minimum operating voltage of the proximity
detector is less than 7.5V. The proximity detector
must be located in the same hazardous area as the
BA377E-SS.
The BA377E-SS contains a configurable debounce
circuit to prevent false triggering of the instrument.
Three levels of debounce protection are available.
See section 6.5.6
3.2.6 Magneti pi k-off input
CoiL in the input configuration menu is a lo level
voltage input intended for use ith an intrinsically
safe magnetic pick-off sensor hich is not suitable
for controlling the BA377E-SS,

14
3.2.7 Voltage input
T o voltage input ranges are independently
selectable in the BA377E-SS configuration menu,
VoLt5 L and VoLt5 H. When configured for either of
the voltage ranges and terminals 3 and 4 are not
linked, the input terminals 5 and 6 comply ith the
requirements for simple apparatus. This allo s the
inputs to be connected to any certified intrinsically
safe voltage source ithin the same hazardous area
as the BA377E-SS having output parameters equal
to or less than:
Uo ≤ 28V dc
Io ≤ 200mA dc
Po ≤ 0.84W
The BA377E-SS Timer may therefore be directly
connected to and controlled by most certified
intrinsically safe high level outputs.
The maximum permitted cable parameters ill be
defined by the intrinsic safety certification of the
voltage source less the BA377E-SS input
parameters hich are small and can often be
ignored.
The BA377E-SS contains a configurable debounce
circuit to prevent false triggering of the instrument.
Three levels of debounce protection are available.
See section 6.5.6
3.2.8 Remote reset
Connecting the external reset terminals RS1 and
RS2 together ill reset the BA377E-SS hen
configured as a Timer and synchronise the displayed
time hen configured as a Clock. Remote resetting
may be accomplished by any mechanically operated
s itch located in the same hazardous area as the
instrument providing the s itch and the associated
iring can ithstand a 500V rms insulation test to
earth. No galvanic isolator is required.
A BA377E-SS may also be remotely reset or
synchronised from the safe area. Any s itch may
be used but a galvanic isolator or IS relay is required
to transfer the contact closure into the hazardous
area. Fig 5 illustrates ho a BA377E-SS Timer may
be reset from both the safe and the hazardous area.
Note: The BA377E-SS can also be configured to
reset hen the & and push buttons are
operated simultaneously in the display mode for
more than t o seconds - see 6.5.19
3.2.9 Control outputs - optional
Each of the t o factory fitted optional control outputs
is a galvanically isolated single pole solid state
s itch as sho n in Fig 7. The outputs are polarised
and current ill only flo 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 7 Equivalent circuit of each control output
Each control output is a separate galvanically
isolated intrinsically safe circuit ith output safety
parameters complying ith the requirements for
simple apparatus. This allo s the control output
terminals A1 & A2 and A3 & A4 to be connected to
almost any certified intrinsically safe circuit protected
by a galvanic isolator providing the isolator has the
correct function and the output parameters do not
exceed:
Uo ≤ 28V
Io ≤ 200mA
Po ≤ 0.84W
The maximum equivalent capacitance and
inductance bet een each set of alarm terminals is:
Ci = 22nF
Li = 8µH (Effectively 0)
To determine the maximum permissible cable
parameters Ci and Li, plus those for any other
intrinsically safe instruments in the loop, should be
subtracted from the maximum permitted external
capacitance Co and inductance Lo specified by the
certificate for the galvanic isolator po ering the
circuit as sho n in Fig 8.

15
Fig 8 Typical control output application
3.3 Use in an Ex e or Ex p panel en losure
lo ated in Zone 1 or Zone 2.
The BA377E-SS ATEX EC-Type Examination
Certificate allo s the Timer or Clock to be installed in
an Ex e IIC Gb increased safety panel enclosure
located in Zone 1 or 2, or in an Ex p IIC Gb
pressurised panel enclosure located in a Zone 1 or 2
hazardous area. The BA377E-SS may also be
installed in an Ex n enclosure located in Zone 2.
When installed in a certified panel enclosure the
BA377E-SS Timer or Clock remains intrinsically safe
and must be protected by a Zener barrier or galvanic
isolator as described in sections 3.1 and 3.2. When
correctly installed, the BA377E-SS Timer or Clock
does not invalidate the certification of the Ex e, Ex n
or Ex p panel enclosure allo ing installation ith
higher po er control equipment.
3.3.1 Installation in an Ex e panel en losure
within Zone 1 or Zone 2.
Installation of a BA377E-SS Timer or Clock in an
Ex e IIC Gb increased safety panel enclosure does
not invalidate the Ex e panel's ingress and impact
protection as the front of the BA377E-SS complies
ith Ex e impact and ingress requirements.
Although mounted in an Ex e panel enclosure, the
BA377E-SS remains Group II Category 1G Ex ia IIC
T5 Ga intrinsically safe apparatus therefore it must
be po ered via a Zener barrier or galvanic isolator
as described in section 3.1 and 3.2 of this manual.
Fig 9 Typical installation in Ex e panel enclosure

16
Some Zener barriers and galvanic isolators are
certified for mounting ithin a protective enclosure
located in Zone 2 hich may permit them to be
mounted in the same Ex e enclosure as the
BA377E-SS Timer or Clock. Zener barriers and
galvanic isolators are not permitted in Ex e
enclosures located in Zone 1.
The Timer or Clock terminals, the iring to the Timer
or Clock and the intrinsically safe interface, if
mounted ithin the enclosure, should be segregated
from all other non-intrinsically safe iring and
equipment ithin the panel enclosure as required by
EN 60079-11 Equipment protected y intrinsic safety
and EN 60079-14 Electrical installations design,
selection and erection.
The Ex e panel enclosure should be fitted ith a
arning label saying 'Do not open hen non-
intrinsically safe circuits are energised', alternatively
all bare live non-intrinsically safe parts ithin the
panel enclosure should have an IP30 cover carrying
a arning label 'Do not open hen energised'.
The po er dissipation ithin an BA377E-SS fitted
ith operational alarms and a backlight is normally
about 350mW. In the very unlikely event that all
three circuits fail to the orst case condition at the
same time, the total po er dissipation rises to 2.5W
hich could raise the internal temperature of a small
thermally ell insulated panel enclosure.
3.3.2 Installation in Ex p panel en losure within
Zone 1 or Zone 2.
Installation of a BA377E-SS Timer or Clock in an
Ex p IIC Gb or Ex p IIC Gc pressurised panel
enclosure does not invalidate the Ex p panel's
impact and ingress protection as the front of the
Timer or Clock complies ith Ex p impact and
ingress requirements. Although mounted in an Ex p
panel enclosure, the BA377E-SS remains Group II
Category 1G Ex ia IIC T5 Ga intrinsically safe
apparatus and must therefore be po ered via a
Zener barrier or galvanic isolator as described in
section 3.1 and 3.2 of this manual.
When installed in an Ex p panel enclosure the four
vents at the rear of the Timer or Clock hich are
sho n in Fig 13 should not be obstructed.
Zener barriers and galvanic isolators may be
installed in the same Ex p enclosure as the
BA377E-SS. All may be mounted in an Ex px
enclosure installed in Zones 1 or 2, or in an Ex pz
enclosure installed in Zone 2, both of hich have a
non-hazardous interior. Some Zener barriers and
galvanic isolators may have certification permitting
installation ithin an Ex py enclosure hich has a
Zone 2 interior.
The Timer or Clock's terminals, the iring to the
Timer or Clock and the intrinsically safe interface, if
mounted ithin the enclosure, should be segregated
from all other non-intrinsically safe iring and
equipment ithin the panel enclosure as required by
EN 60079-11 Equipment protected y intrinsic safety
and EN 60079-14 Electrical installations design,
selection and erection.
If live maintenance is anticipated, it is recommended
that the Ex p panel enclosure should be fitted ith a
arning label saying 'Do not open hen non-
intrinsically safe circuits are energised', alternatively
all bare live non-intrinsically safe parts ithin the
panel enclosure should have an IP30 cover carrying
a arning label 'Do not open hen energised'.
Fig 10 Typical installation in Ex p panel enclosure

17
4. INSTALLATION
4.1 Lo ation
The BA377E-SS has a stainless steel case ith a
10mm thick toughened glass indo . The case
provides 7J and the indo 4J front of panel impact
protection. The captive silicone gasket, hich seals
the joint bet een the instrument and the panel
enclosure, ensures IP66 front of panel ingress
protection. The rear of the Timer or Clock has IP20
protection.
Although the front of the BA377E-SS has IP66
protection, it should be shielded from continuous
direct sunlight and severe eather conditions.
The BA377E-SS may be located in Zone 0, 1 or 2
providing that the operating temperature is bet een
–40°C and +60°C and the installation complies ith
the certification requirements.
Installation in Ex e and Ex p panel enclosures are
described in sections 3.3.1 and 3.3.2.
Fig 11 sho the overall dimensions of the
BA377E-SS together ith the recommended panel
enclosure cut-out dimensions and Fig 13 sho s the
terminal locations.
4.2 Installation Pro edure
a. Cut the aperture specified in Fig 11 in the panel
enclosure. Ensure that the edges of aperture are
de-burred.
b. Inspect the Timer or Clock's captive gasket and
ensure that it is not damaged before inserting the
Timer or Clock into the panel enclosure aperture.
c. If the enclosure panel is less than 1.0mm thick, or
is non-metallic, an optional BEKA stainless steel
support plate should be slid over the rear of the
Timer or Clock before the panel clamps are fitted
to evenly distribute the clamping force and prevent
the enclosure panel being distorted or creeping.
d. Slide a panel clamp into the t o grooves at each
corner of the indicator housing ith the M3 stud
protruding through the hole at the rear of the
clamp. Fit the stainless steel spring asher over
the stud and secure ith the stainless steel ing
nut.
e. Evenly tighten the four clamps to secure the
instrument. The recommended minimum
tightening torque for each ing nut is 22cNm (1.95
lbf in).
f. Connect the panel enclosure iring to the rear
terminal blocks as sho n in Fig 13. To simplify
installation, the terminals are removable so that
iring can be completed before the instrument is
installed. Cables should be mechanically secured
to ensure terminals are not damaged by vibration.
g. Finally, fit a silicone rubber push-on cap to the end
of each M3 threaded rod.
Support panel iring to prevent vibration damage
Note: Optional backlight is internally po ered
Fig 11 Dimensions

18
Fig 12 Installation procedure
4.3 EMC
The BA377E-SS complies ith the requirements of
the European EMC Directive 2014/34/EU. For
specified immunity all iring should be in screened
t isted pairs, ith the screens earthed at one point
ithin the safe area.
Fig 13 terminal
4.4 Timer or Clo k earthing
The BA377E-SS has an M4 earth stud on the rear
panel hich should be electrically connected to the
panel enclosure in hich the instrument is mounted,
or to the plant equipotential conductor.
4.5 S ale ard
The Timer or Clock’s units of measurement are
sho n on a printed scale card in a indo at the
right hand side of the display. The scale card is
mounted on a flexible strip that is inserted into a slot
at the rear of the instrument as sho n in Fig 14.
Thus the scale card can easily be changed ithout
removing the Timer or Clock from the panel or
opening the instrument enclosure.
Ne Timer or Clocks are supplied ith a printed
scale card sho ing the requested units of
measurement, if this information is not supplied
hen the instrument is ordered a blank card ill be
fitted.
A pack of self-adhesive scale cards printed ith
common units of flo measurement is available as
an accessory from BEKA associates. Custom
printed scale cards can also be supplied.
To change a scale card, unclip the tapered end of the
flexible strip at the rear of the instrument by gently
pushing it up ards and pulling it out of the
enclosure. Peel the existing scale card from the
flexible strip and replace it ith a ne printed card,
hich should be aligned as sho n belo . Do not fit
a ne scale card on top of an existing card.
Install the ne scale card by gently pushing the
flexible strip into the slot at the rear of the Timer or
Clock, hen it reaches the internal end-stop secure
it by pushing the end of the flexible strip do n ards
so that the tapered section is held by the rear panel.
Align the self-adhesive
printed scale card onto the
flexible strip and insert the
strip into the indicator as
sho n belo .
Fig 14 Inserting the flexible strip carrying the scale
card into the slot at rear of instrument.

19
5. ACCESSORIES
5.1 Display ba klight
The BA377E-SS Timer and Clock can be supplied
ith a factory fitted backlight that produce green
illumination enhancing display contrast and enabling
it to be read at night or in poor lighting conditions.
The backlight is internally po ered from the
instrument po er supply so no additional iring or
intrinsically safe interface is required, but the supply
current increases as sho n belo .
BA377E-SS Timer
urrent
onsumption
Without backlight 10mA
Additional for backlight 22mA
Addition ith terminals 3 & 4 linked 6mA
---------------
Total current 38mA max
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 ill be used for the
majority of Timer applications. If control outputs are
required they should be specified hen the
instrument is ordered.
5.3 S ale ard
The BA377E-SS has a indo on the right hand
side of the display through hich a scale card
sho ing the units of measurement such as hours
can be seen. Ne instruments are fitted ith a
scale card sho ing the units of measurement
specified hen the instrument as ordered, if the
units are not specified a blank scale card ill be
fitted. A pack of scale cards pre-printed ith
common units of measurement is available as an
accessory. These can easily be fitted on-site ithout
opening the instrument enclosure or removing it from
the panel. See section 4.5 of this instruction manual.
Custom scale cards for applications requiring less
common units of measurement are also available.
5.4 Tag information
Ne instruments can be supplied ith a tag number
or application information printed onto the rear panel
adjacent to the terminals. This information is not
visible from the front of the instrument after
installation.
5.5 Rear over sealing kit
The BA377E-SS Timer or Clock’s rear of panel
ingress protection can be increased from IP20 to
IP66 ith a BA495 rear cover sealing kit.
Manufactured from 316 stainless steel the cover
incorporates t o M20 unthreaded entries for cable
glands.
It allo s the BA377E-SS Timer or Clock to be
installed as an intrinsically safe instrument in an
open panel or to provide additional rear protection
hen installed ithin an Ex e enclosure.
Note: The BA495 rear cover is not certified to
provide Ex e protection, it only increases the
instrument’s rear protection to IP66.

20
6. OPERATION AS A TIMER
When configured as a Timer the BA377E-SS can
measure and display the elapsed time bet een
external events such as measuring and displaying
ho long machinery is operating. The Timer can be
started and stopped by a remote sensor ith a
continuous output, or from the front panel push
buttons.
The addition of t o optional factory fitted isolated
control outputs allo s the Timer to control external
events such as opening a valve for a predetermined
time. Again the Timer can be started and stopped by
a remote sensor, or from the front panel push
buttons.
When controlling external events the CYCLE function
enables the BA377E-SS Timer to be configured to
repeat the timing period up to 99 times ith a
configurable delay bet een timed periods up to 100
hours or to repeat continuously.
The BA377E-SS may be configured to time-up from
zero to the set time 5Et t, or to time-down from the
set time to zero. The set time may be entered and
displayed in hours, minutes or seconds, or a
combination of units. Elapsed or remaining time is
continuously displayed and a separate display may
be activated to sho the Timer set time 5Et t.
Resetting the timer cycle can be accomplished via
the front panel push buttons or by a remote contact.
A grand total time is maintained hich can be vie ed
by operating the front panel push buttons. It may be
reset to zero from ithin the configuration menu, or
the instrument may be configured to allo resetting
from the front panel push buttons.
Fig 15 sho s a simplified block diagram of the
BA377E-SS hen configured as a Timer. The input
can be configured to accept inputs from a ide
variety of sensors. When the sensor requires
energising, such as a s itch contact, open collector
or a t o ire proximity detector, a link connected
bet een terminals 3 & 4 supplies po er to the
sensor input.
The instrument can be supplied ith the follo ing
factory fitted accessories:
Internally po ered Backlight
Dual isolated Control Outputs
The t o factory fitted solid state isolated control
outputs may be independently configured to close
and open at specified parts of the timer cycle, such
as hen the timer starts or finishes.
6.1 Initialisation
Each time po er is applied to a BA377E-SS
initialisation is performed. After a short delay the
follo ing display sequence occurs:
All segments of the display are activated
BA377E-SS is ready to start functioning
using the configuration information stored in
the instrument's permanent memory.
Fig 15 BA377E-SS block diagram ith Timer
configuration.