Duomo BX444-Mc User manual

BX444Mc GasDetectionController
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FEATURES
■4 Zone Protection
■O2depletion or excess monitoring
■Digital display with colour change feature
■Positive Safety Option
■Detection of Toxic 0-300ppm / Explosive Gas(es) 0-20%LEL /
Oxygen (O2) 0-25%
■4-20mA signal sensor input
■3 Stages of Alarm - 1st & 2nd level and Main Alarm
■IP44 Protective Rating
■CE Certied and approved to EN61010-1 and EN50270
■2 Year Guarantee - 3 Year by Registering at duomo.co.uk
OPERATION
The BX444Mc can be congured to detect explosive or toxic gases.
A back-lit colour display scrolls through each sensor and reports
their individual status. When any connected sensor detects the
presence of the target gas a proportional 4-20mA signal is sent to
the detector.
The BX444Mc then operates a pre-alarm relay (used for remote
sirens or visual indicators). If the level of gas continues to rise then
the second pre-alarm is actuated.
In the case of explosive gases, when the level of gas reaches 20%
LEL, the main alarm relay is activated to break the electrical supply
to the gas safety shut-o󰀨 valve (SSOV). A separate volt-free sensor
fault relay actuates if the correct return signal is not sensed by the
detector.
BX444MC 4 Zone Gas Detection Controller
SPECIFICATION
Power
Power Supply 230V AC 50Hz ± 10%
Secondary Battery 12V DC ± 10% Max 2.2Ah
Battery Charger Charger Capacity 2.2Ah
Power Consumption 12V - 5W Maximum
230V - 9.3W Maximum
Relay contact range 10A resistive 250VAC, 5A 30VDC Resistive
Alarm Settings
Pre-Alarm No.1 8% LEL / 120ppm
Pre-Alarm No.2 13% LEL / 200ppm
Main Alarm Fixed at 20% LEL / 300ppm
Sensor Fault Short circuit, interruption, sensor deterioration
Technical Specication
Dimensions Width 144mm | Height 144mm |Depth 110mm
Display Digital display with colour change feature
Mounting Wall or Panel Mounted
Input Signal 4-20mA
Device Precision 1% FS
Reaction Time <2 seconds
Working Temperature -10°C to 60°C
Start-up Self Diagnostic Delay 90 seconds
Protective Rating IP44
Conguration
Positive Safety Yes (ON/OFF)
Main Alarm Relay Actuation Yes (Latching/Temporary Alarm)
Gas Type Selection Yes (Toxic/Explosive)
Timed Sensor Test Facility Yes
Emergency Stop Connections Yes
O2Compatibility as Standard Yes
Perhipheral Specication
No. of Remote Sensors 1-4
Maximum Sensor Distance 100m
Cable Diameter for Sensors 1mm2CSA
(Screened and earthed at the controller end)
Compatibility
Sensor Compatibility All Duomo Sensors
Approvals, Certications and Guarantee
Approvals EN 61010-1 EN50270
Guarantee 2 Year as Standard
3 Year by Registering at www.duomo.co.uk
4
Zone / Sensor
O2
Monitoring
8888
Colour Change
Digital Display
Positive
Safety
IP44
EN61010-1
EN50270

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BX444Mc GasDetection Controller Overview
The BX444Mc is a wall or panel mounted microprocessor based gas detector control unit. It has a secure test facility
which allows sensors to be fully tested by applying test gas without disconnecting the electrical supply to Gas valves.
The BX444Mc can be congured to meet customer requirements. The following parameters can be changed using on
board DIP switches:
• Number of sensors from 1 to 4
• Type of gas to be sensed (explosive or toxic)
• Positive Safety Option (on or o󰀨)
• Main alarm relay action (latching or auto-reset)
The BX444Mc has two plug in terminal blocks. One is for the incoming mains supply and alarm circuit wiring and the
second is for connecting the sensor wiring.
This reduces the chance of incorrect site wiring. The front panel has two overload lights which indicate when a short
circuit or an overload has occurred on the sensor wiring.
144 77
108
144
140
141
141
Cutout
Dimensions (mm)
Mounting Bracket
Control panel
Mounting the BX444Mc
Overall Dimensions (mm)

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000
ppm
ON
1 2
ON
1 2
ON
1 2
ON
1 2
ON
1 2
4 5NPh 6 7 8 9 10 11 12 4 5321 6 7
ON
1 2
BX444-Mc
1
2
3
4
5
6
8
7
9
10
11
12
13
14
15
18
16
17
19
20
21
BX444Mc Fascia & PCB Layout
No Description Purpose & Functionality
1 ON LED illuminates when supply voltage is applied.
LED ashes during self diagnosis start up.
2 SERVICE REQUIRED This LED ashes when the scheduled service is required. Reminder set to either six months or one year
(determined by risk assessment). Contact Duomo UK on [phone]
3 SENSORS OVERLOAD LED Illuminated to indicate short circuit or overload on sensor circuitry.
4 BATTERY OVERLOAD LED Illuminated to indicate incorrect battery connection or high consumption during charging phase.
5 TEST
When pressed checks the sequence and function of BX444Mc.
Press and hold to initiate a full function test, release once controller is in alarm state required
Will eventually activate all relays and their associated outputs.
6 RESET When pressed resets the detector after an alarm or sensor fault condition.
7 LCD Display Represents current BX444Mc status (Normal/Test/Fault/Alarm), Connected sensors (Sensor readings and
settings scroll automatically), Indicates alarm condition and status. (See LCD Display Interface).
8 1st ALARM
At 8% LEL (Explosive) or 120ppm (Toxic) gas concentration:
LED illuminates and the Pre-Alarm relay No.1 is actuated.
(This relay output deenergises when level of gas exceeds 2nd ALARM levels).
9 2nd ALARM At 13% LEL (Explosive) or 200ppm (Toxic) gas concentration:
LED illuminates and the Pre-Alarm relay No.2 is actuated.
10 MAIN ALARM At 20% LEL (Explosive) or 300ppm (Toxic) gas concentration:
LED illuminates and the Main Alarm relay is actuated.
11 FAULT LED illuminates to Indicate short circuit, sensor fault, loss of signal, incorrect sensor connection or failure
(In case of sensor failure LED will ash when relevant sensor is scanned).
12 LEL (EXPLOSIVE) LED illuminates when internal DIP switch (CO/GAS) for a sensor is moved to GAS (Explosive) position.
As the sensor value is displayed the corresponding LED for that sensor is illuminated.
13 ppm (TOXIC) LED illuminates when internal DIP switch (CO/GAS) for a sensor is moved to CO (Toxic) position.
As the sensor value is displayed the corresponding LED for that sensor is illuminated.
14 Supply & Relay Terminals Electrical supply and relay connections. (See Wiring Schematic for connection instructions).
15 Sensor switches Used to enable or disable a sensor on a zone (ON/OFF) or determine type of gas to be detected (Toxic/
Explosive) - (See Conguring the BX444Mc section for setting instructions).
16 Positive Safety switch Positive Safety switch (See Conguring the BX444Mc section for setting instructions).
17 Oxygen detection switch If set to ON then the BX444Mc can only be used for Oxygen detection and no other types of sensors for any
other gases can be used. (See Conguring the BX444Mc section for setting instructions).
18 Sounder Operation switch Determines if Sounder remains operational if gas levels drop below alarm threshold.
(See Conguring the BX444Mc section for setting instructions).
19 Main Alarm Relay actuation Determines if Main Alarm relay remains in position even if gas levels drop below alarm threshold.
(See Conguring the BX444Mc section for setting instructions).
20 Emergency Stop
Connection Terminals
Remove link when Emergency Stop Button is tted. (See Wiring Schematic for connection instructions).
21 Sensor/ Battery Terminals Sensor and Battery (if tted) terminals (See Wiring Schematic for connection instructions).

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Indicates BX444Mc is in warm up phase with countdown timer at 89 seconds remaining.
A Red backlit display indicates there is an alarm condition.
LEL (Lower Explosive Limit) label shows a sensor is for detection of explosive levels of gas.
20 as concentration level would 20% of the LEL
a
b
c
d
aConcentration of gas at the displayed sensor number.
(Updated every 4 seconds).
bThe number of the sensor to which the concentration
applies.
cShows if the sensor is a toxic or explosive sensor.
dTimer symbol indicates BX444Mc is in warm up phase.
Displayed number is seconds until full operation phase.
LCD Display Interface
Warm up Phase
Normal Condition
Alarm Condition Toxic (ppm) setting
Alarm Condition Explosive (LEL) setting
Fault Condition
A Green backlit digital display indicates normal condition.
The display shows an absense of a gas leakage at sensor 1.
A Red backlit display indicates there is an alarm condition.
ppm (parts per million) label shows a sensor is for detection of toxic levels of gas.
300 as concentration levels would be 300ppm of target gas.
A Yellow backlit display indicates a short circuit, sensor fault, signal loss, incorrect sensor
connection or failure (In case of sensor failure LED ashes when relevant sensor is
scanned).

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Configuring the BX444Mc
The BX444Mc has three pairs of DIP switches on the PCB. The left switch on rst three double switches is used to enable
or disable the sensor for that respective zone. The right switch is used to congure the controller to indicate whether the
connected sensor is for explosive or toxic gas.
The BX444Mc can be congured to provide several modes of operation. The congurable parameters are:
Left switch on any of the 1st 4 double DIP switches
The BX444Mc will not look for a sensor on a given zone if the switch is moved to the OFF position.
It is not necessary to remove the return cable from the sensor.
Example shows Zone 1 On, Zone 2 On and Zone 3 O, Zone 4 O.
Left switch on 5th double DIP switch
Positive safety determines the condition of the main alarm relay and hence the operation of the gas
valve. When it is 'ON' the relay is in a normally open state. When it is 'OFF' the relay is in a normally
closed state. NOTE: This a󰀨ects how the gas valve operates and means that you may need to
change how it is wired to the BX444Mc. Example shows Positive Safety on
Left switch on 6th double DIP switch
Determines whether the audible alarm remains operational after levels have dropped. In memory
mode, the alarm remains and will need to be manually reset. In non memory mode, the alarm will
automatically reset after levels have dropped.
Example shows memory ON
Left switch on 6th double DIP switch
With switch 4 in the on position the BX444Mc is congured to indicate oxygen levels. The function
is determined by setting either excess oxygen or oxygen depletion on the sensor itself (Duomo
SGF104). Example shows oxygen monitoring ON
IMPORTANT NOTE. If Oxygen setting is selected it is not possible to connect any other types of
sensors for any other gases. For example natural Gas or CO
Right switch on any of the 1st 4 double DIP switches
Toxic or explosive levels. These are labelled as GAS or CO on PCB. The symbols on the front fascia
of the detector are EN standard symbols and refer to any explosive or toxic gas. If toxic gas, e.g.
carbon monoxide is to be sensed on a given zone move the switch to the CO position. If explosive,
e.g. natural gas, LPG, hydrogen etc. move the switch to the GAS position.
Example shows Zone 1 Explosive, Zone 2 Explosive, Zone 3 Toxic, Zone 4 Toxic,
Right switch on 5th double DIP switch
Main Alarm relay actuation method. This can be congured to provide either a latching or a temporary
alarm operation. When the main alarm is actuated in an alarm condition if the switch is in the 'C'
position the relay will remain in this position even after the concentration of gas has reduced below
the alarm threshold. If the switch is in the 'I' position the main alarm relay will actuate for 60 seconds
and then if the level of gas has dropped will return to the volt-free main alarm relay to the running
condition.The indication on the panel fascia and the audible alarm will still indicate main alarm. This
mode of operation is used when using manual reset gas valves and battery back-up systems for
extending standby battery life. Example shows detector congured for a latching main alarm
Gas Sensed
Main Alarm Relay
Reset Pressed
Time
1 minute
Gas Sensed
Main Alarm Relay
Reset Pressed
Main Alarm switch in ’l’ position
Time
Main Alarm switch in ’C’ position

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Note:
Connections when Positive Safety is o
Note:
Connections when Positive Safety is on
*1mm2 CSA cable only
Power Supply
230V AC
Emergency Stop
(Link if not required
BX444Mc wiring schematic
Sensor Installation
The sensors must be mounted as shown below with the
sintered head pointing vertically down. When replacing
sensors never seperate a sensing head from its PCB. The
sensor will have been calibrated using this particular board
and therefore will not function correctly with any other.
Electrical Installation
The BX444-Mc is a safety device designed to give audible
alarms and automatically provide latched electrical isolation
of associated gas safety shut o󰀨 valves in the event of a gas
leak or build up of toxic gases.
The sensors can be located up to 100m from the gas detector.
Cable size should be 1mm2CSA. If the sensor cables are
run separately in specic conduit it is not essential to use
screened cable but if the cables are routed through conduit
or trunking containing other wiring the use of screened cable
is advisable. The wiring should be performed by a qualied
person in accordance with current regulations. The plug-in
terminal rail makes installation easy and quick. Do not mount
close to any heat source or in an area where moisture is
likely to e󰀨ect operation. The IP rating of this unit is IP44.
Sensors should be positioned as shown below.
If you require any guidance on this please call Duomo
technical support on [phone].
Important Notes
Always check the wiring before powering up the system.
Do not test this sensor with anything other than Duomo
test gas (See 'BX444Mc Operation' section for further
information). Concentrations above this will damage the
sensor and shorten sensor life.
The installation of this gas detector does not release
the user from observing all the regulations concerning
the characteristics of the installation and the use
of gas appliances; the ventilation of the protected
environment and the removal of products of combustion.
Duomo will not be held responsible or liable for any damage
caused to people, property or animals resulting from incorrect
connection, installation or application of this gas detector. To
ensure correct function after installation Duomo provide a
commissioning service using calibrated test gases. For this
service call [phone].

Sensor range for use with BX444Mc
HCF100 Refrigerant Gas Sensor
CO233A CO Sensor
SGM595 Methane or LPG Sensor
CO100AR CO Sensor
Technical Specication
Gas(es) Detected Carbon Monoxide
Dimensions Width 100mm | Height 100mm | Depth 60mm
Display 6 Colour Digital Display
Sensor Technology Electrochemical
Settings Preset to TWA and STEL Standards
Output Signal 4-20mA
Sensor range 0-300ppm
Working Temperature -20°C to +50°C
Autosetting Yes
Protective Rating IP65
Approvals EN50270 & EN45544-1-3 Compliant
Technical Specication
Gas(es) Detected Freons (Inc R134A, R404A, R407C, R410A)
Dimensions Width 76mm | Height 150mm |Depth 58mm
Display N/A
Sensor Technology Semiconductor
Settings N/A
Output Signal 4-20mA
Sensor range 0-300ppm
Working Temperature -10°C to +60°C
Autosetting Yes
Protective Rating IP55
Approvals EN50270 & EN45544-1-3 Compliant
Technical Specication
Gas(es) Detected Carbon Monoxide
Dimensions Width 100mm | Height 100mm | Depth 60mm
Display N/A
Sensor Technology Electrochemical
Settings Preset to TWA and STEL Standards
Output Signal 4-20mA
Sensor range 0-300ppm
Working Temperature -15°C to +40°C
Autosetting Yes
Protective Rating IP55 (Enclosure) IP65 (Sintered Head)
Approvals BS EN50291 Compliant
Technical Specication
Gas(es) Detected Methane and LPG
Dimensions Width 73mm | Height 108mm |Depth 57mm
Display N/A
Sensor Technology Catalytic
Settings N/A
Output Signal 4-20mA
Sensor range 5% to 20% LEL
Working Temperature -10°C to +60°C
Autosetting Yes
Protective Rating IP55
Approvals EN50194 Compliant
IP65
IP55
4-20mA
4-20mA
4-20mA
4-20mA
8888
Colour Change
Digital Display
IP55 IP55 Propane
Freons Methane
CO CO

Sensor range for use with BX444Mc
SGF104 Oxygen Sensor
SG895 ATEX Sensor SG500 Methane or LPG Sensor
Technical Specication
Gas(es) Detected Methane, LPG, Ammonia, Hydrogen, Acetylene, Gasoline,
Methanol, Ethanol, White Spirit, Acetone, Hexane,
Ethyl Acetate, Toluene
Dimensions Width 100mm | Height 133mm |Depth 70mm
Sensor Technology Pellistor
Settings 0-20% LEL (0-300ppm for Carbon Monoxide)
Output Signal 4-20mA
Sensor range 0 - 100% of LEL or di󰀨. in ppm
Working Temperature -10°C to +70°C
Autosetting Yes
Protective Rating IP65
Approvals ATEX RATED EN60079-0, EN60079-1, EN61241-0 &
EN61241-1 Compliance
Technical Specication
Gas(es) Detected Oxygen
Dimensions Width 100mm | Height 100mm | Depth 60mm
Sensor Technology Optical (Fluorescence based)
Settings 19.5 or 18.5% of O2(depletion), 22.5, 23.5% (excess)
Output Signal 4-20mA
Sensor range 0-25%
Working Temperature -30°C to +60°C
Autosetting Yes
Protective Rating IP64
Approvals EN50104 and EN50270 Compliant
Technical Specication
Gas(es) Detected Methane or LPG
Dimensions Width 110mm | Height 50mm |Depth 35mm
Sensor Technology Catalytic
Settings N/A
Output Signal 4-20mA
Sensor range 0-20% LEL
Working Temperature -0°C to +40°C
Autosetting No
Protective Rating IP30 (Enclosure)
Approvals N/A
Calibration Gas
Available in 12L & 110L Cannisters
Valves and other spares also available
4-20mA4-20mA
4-20mA
IP64
IP65 IP30
10+
Gases
LPG
Methane
O2

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BX444Mc Operation test proceedure
Before powering up the BX444Mc once again check that all electrical connections are correct.
1Apply 230VAC supply to the Ph and N terminals. Ensure that the correct fuse is used in the supply (3A or 5A max)
2All of the LEDs on the fascia will illuminate in sequence which allows an oppurtunity to visually check the functionality of all the LEDs.
This process takes approximately 20 seconds.
3
The ON LED will remain ashing for 90 seconds. During this period the BX444Mc is in warm up phase. Gas detection functionality is
not available during this period.
When the ON LED remains stable the BX444Mc is in full operation mode.
4
Please note: The BX444Mc is not in override, the following step will activate relay outputs when Alarm level readings are exceeded.
By pressing and holding the TEST button a function test can be performed for all Pre-Alarm and Main Alarm relays together with LEDs
and internal buzzer. If a full test is required then hold the TEST button until 300ppm or 20%LEL reading is exceeded to activate all
relays.
The sequence will be:
(a) At 8% LEL/ 120ppm reading - Pre-Alarm no.1 relay actuated, 1st ALARM LED illuminates and Terminal 6 and 7 will be connected.
(b) At 13% LEL/ 200ppm reading - 1st ALARM outputs listed in step (a) are all deactivated (Relay, LED and Terminal connections) .
Pre-Alarm no.2 relay actuated, 2nd ALARM LED illuminates and Terminal 8 and 9 will be connected.
(c) At 20% LEL/ 300ppm reading - The Main Alarm relay is actuated, MAIN ALARM LED illuminates and Terminal 10 and 11 will be
connected and terminals 10 and 12 will be broken and the audible alarm will continue to sound (With Positive Safety On terminals 10
and 11 will be broken and terminals 10 and 12 will be connected).
The relevant Alarm LED will illuminate to show which zones are in alarm.
By releasing the TEST button the LED will go out and the audible alarm will stop. If latched alarm function on the main relay is
congured this will remain on until the RESET button is pressed.
5
In order to conduct a full function test and calibration it is essential to use Duomo (UK) Ltd or equivalent calibrated test gas. The
maximum concentrations are:
40% Methane (CH4) in Air
350ppm Carbon Monoxide (CO)
0.85% (MOL) for Propane
Any higher can reduce sensor lifespan. Note: NEVER TEST WITH NEAT GAS. THIS WILL POISON THE SENSOR.
6
To simulate a sensor fault and test associated outputs:
Disconnect the sensor plug The detector will go into FAULT ALARM and the sensor fault relay will be actuated as well as the FAULT
LED. This will close the contacts between terminals 4 and 5 and open the contacts between terminals 10 and 12 (Main Alarm relay).
When the plug is reconnected the detector can be reset by pressing the RESET button.

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Troubleshooting
The Problem The Solution
No light are illuminated on the fascia of the
detector
Check that the electrical supply is reaching the device and that the plug in terminal rail is pushed
into place.
One or all of the sensor fault lights are
illuminated
Check that the plug is inserted correctly.
Check that the sensor wiring is correctly terminated at both the detector and the sensor. Check that
12V DC is present at the sensor. The green LED on the sensor should be illuminated.
By pressing the TEST button on the detector fascia it is possible to check the e󰀩ciency of the
device and if the sensors have been connected correctly.
Sensor fault continues to alarm Check the sensor wiring. If the red Overload LED is illuminated then a short circuit or overload has
occured on the sensor or connecting cable.
The detector is subject to repeated alarms Ensure that there is not an occasional gas leak. This may be due to a valve or joint which leaks
under pressure.
The detector is in main alarm condition and
the main gas valve is not closing
Check that the connections are correct and that power is supplied to the valve i.e. The valve is not
stuck in the open position. The function of the alarm relays both the Pre-Alarm and the Main Alarm
can be checked by pressing the TEST button on the detector fascia. Check that the main alarm
action is congured for a latching alarm.
(Switch 2 on 5th DIP switch - See Conguring the BX444Mc)
There is no supply to the solenoid valve
The Main Alarm relay is a volt free contact, therfore you must connect the live supply to the
common of the main alarm relay contacts terminal 10.
A supply will then come from terminal 12 to the solenoid valve.
The sensor is connected but no LED is lit on
the front fascia
Check that the DIP switch is set to the ON position for the sensor
(Switch 1 on one of the rst three DIP switches - See Conguring the BX444Mc
In case of alarm
Extinguish any naked ames.
Do not switch lights or electrical devices on or o󰀨.
Open all windows and door to increase ventalation.
• If the ALARM LED is o󰀨 the levels of gas have dropped. A responsible, qualied person is now safe to nd the cause of the alarm.
• If the alarm sound reamins constant and the cause is not evident or not possible to eliminate turn o󰀨 the emergency isolation valaves to the area and
contact your gas provider emergency line. They will advise accordingly.
Still experiencing difficulties?
If you have made the checks above and are still experiencing di󰀨culties then please call Duomo (UK) Ltd on
[phone] for technical assistance.