BX444 Gas Detector

Detects Carbon Monoxide,Natural Gas & L.P.G.

230V and 12V DC.

One, two, three or four Zone.

Self Diagnostic

Manual or Automatic Reset

Adjustable Pre-Alarm

Catalytic and Electrochemical Sensors

Audible Alarm

Sensor Fault Alarm

Manual Test Function

144 x 144 DIN Enclosure

Panel or wall Mounting

1 Year Guarantee

Duomo is recognised within the Gas industry forproviding a comprehensive range of low cost, highreliability gas detection for many applications. Wehave installed and commissioned Natural gas andcarbon monoxide sensors in applications such asboiler rooms, kitchens, car parks, aircraft hangars,factories and shopping centres.ApplicationThe BX444 has been designed to meet all EuropeanNormative proposals for the detection of Natural Gas,LPG and Carbon Monoxide Gas Detectors. The BX444is provides protection from gas leakage in areas suchas Boiler Rooms Roof spaces unventilated voids. Car-bon Monoxide is an invisible, odourless gas which in-hibits the bodies ability to process Oxygen. The BX444protects against this in underground or poorly venti-lated car parks, boiler rooms, vehicle servicing areasetc. Remote sensors are installed in the areas whichrequire connected to remote sensors located in the pro-tected area. The 144 x 144 enclosure is wall or panelmounting.OperationIf the remote sensors sense the presence of Gas thedetector operates a pre-alarm relay - used for remotesirens or extract fans; if the level of gas continues torise then the main alarm relay is activated to, either inthe case of explosive gases, break the electrical sup-ply to the Safety Shut Off Valve or for CO sound a Gen-eral Alarm to allow evacuation of the area.

FeaturesThe Pre-Alarm can be adjusted, in the case of Natu-ral Gas or LPG, from 8% to 15% of the Lower Ex-plosive Level (LEL). For Carbon Monoxide, it canbe adjusted from 120ppm to 250ppm. The MainAlarm thresholds are not adjustable and are fixed at20% LEL for explosive gas and 300 ppm for Car-bon Monoxide. The detectors can be set for eithertoxic or explosive Gas. Or both.

It is possible to set one zone for explosive gas suchas Natural Gas or LPG and another for toxic gas forexample Carbon Monoxide. An LED display on thefascia indicates the levels of detected gas in either:-parts per million (ppm) or percentage of Lower Ex-plosive Level (%LEL). Lights above the display indi-cate which sensor the Numeric LED display refersto. It is possible to use the detector as a one, two,three or four zone by enabling or disabling eachchannel.

A ‘TEST’ button on the facia, when pressed, checksthe complete function of the BX444 and sensors. Apermanent diagnostic check is made of sensor func-tion. If any sensors should become faulty or be con-nected incorrectly the ‘FAULT’ light will illuminateand the detector will fail safe.

CAUTION!Carefully read the following instructions prior to installation of this device. Alwayskeep this pamphlet for future reference. Ensure that the gas detection system iswired correctly, the appropriate sensor is installed and used only for the purposewhich it is intended.

BX444 Four ZoneGas Detector

Key

1 EXPLOSIVE - Indicates when the natural gas & LPG function is selected.2 SENSOR LED’s - These show which sensor the displayed levels refer to.3 Numeric LED display - This shows the concentration of detected gas in either ppm or as %LEL.4 LEL - This shows that the numeric display refers to % LEL .5 ON - indicates external power source is healthy.6 BATTERY - 12V battery connected rather than mains supply.7 PRE-ALARM - Indicates when the gas level has reached the selected pre-alarm threshold.8 MAIN ALARM- Indicates when the concentration of gas reaches 20% LEL Methane or 300ppm of

Carbon Monoxide.9 PPM - The LED numeric display refers to parts per million of the detected gas.10 RESET - Press to reset alarm. This resets the detector memory.11 TEST- Push button. Provides full function test of detector.12 FAULT - Flashes when the sensor is either faulty, connected incorrectly or not selected.13 OVERLOAD - Power consumption of the BX444 is too high.14 TOXIC - Indicates that the Carbon Monoxide function is selected.

BX444 Facia

6

7

8

910

11

12

13

14

1 2 3 4 5

Digital Display

This shows the quantity of gas detected by each sensor.The display can be configured to display values in partsper million (ppm) percentage of the lower explosive level(LEL). As the blue lights marked 1 to 4 illuminate, thevalue shown on the display corresponds to the gas levelsdetected by sensors 1 to 4 respectively. During the Resetprocedure the explosive, toxic, sensor 1,2,3 and 4 lightswill flash. The display will scroll through numbers up to

990 for each zone and then will stabilize at 000.

Installation

Mounting the detector

The BX444 can be wall mounted or panelmounted. See fig.(2) for panel cutout dimen-sions . When panel mounted the supportbracket supplied loose should be fitted as shownin fig.(3)

Cable gland entries are provided in the form of 2pre-moulded 20mm ‘knockouts’ in the back ofthe BX444 box. Alternatively it is possible tocarefully drill into the sides of the box. Note: Seefig.(4) for suitable drill positions. Always ensurethat the printed circuit board will clear the cablegland when closed. It is recommended that thePCB facia assembly is removed prior to drillingfor gland entry.

Positioning Sensors

The SG590 (Methane) and CO100 (CarbonMonoxide) Sensors should be mounted inaccordance with the following considerations.Do not position next to burners, heaters orovens where temperatures above the roomambient may be experienced. It is, if possible,better to mount the sensors on the oppositewall. This is, of course, dependant on the size ofthe protected area.

Natural Gas is lighter than air and therefore willobviously rise, therefore the SG590 (methane)sensor should be mounted 300mm from theceiling of the protected area.

For LPG (Propane and butane) the SG590 LPGmust be connected. LPG is heavier than air sothe sensor must be located 300mm from floorlevel.

Carbon Monoxide has specific gravity of 0.97and is therefore slightly lighter than air. Howeverfor positioning purposes at the concentrations ofCO relating to the detector alarm thresholds theresultant combination of CO and air will neitherrise or fall. The best position to mount theC0100 is 1.6m above ground level.

If you require assistance regarding locating sen-sors please call our Droitwich Factory on (01905)797989 alternatively fax a drawing of your appli-cation to (01905) 774296 and we will advise ac-cordingly.

Fig.2

Fig.3

Fig.1

Typical External Wiring Diagram for BX444

Electrical Connection

The sensor can be located up to 100m from the gasdetector. Cable size should be 1mm CSA. If thesensor cables are run separately in specific conduit itis not essential to use screened cable but if the cablesare routed through conduit or trunking containing otherwiring the use of screened cable is advisable. Thewiring should be performed by a qualified person inaccordance with current regulations.

Fig.4

Cable Entry Points

The plug in terminal rail makes installation easy andquick.

Note: It is essential that enough length is left in thecable loom to allow the facia to be hinged open asshown in fig (3). The wiring must be checked prior topowering up the system.

Configuring the detector

How Many zones....?The BX444 can be configured to provide one, two,three or four zone protection. Sensors are enabledand disabled by switching the zone select switches on

and off. To disable a zone movethe switch to the ON position. Theswitches shown are in the zoneenabled position. When you havemade the switch change press thereset on the BX444 fascia.

Gas or Carbon Monoxide...?If the gas to be sensed is Explosive you must firstensure that the correct sensor is connected to thesystem. For instance, for Natural Gas SG590. Each

pair of switches shownbelow corresponds to asensor. From left toright, 1 to 4. To selectthe Explosive Indicationon the fascia for aparticular sensor moveswitch 1 to the ON

position and switch 2 to the off position. If anotherzone is being used to sense carbon monoxide, againensure that the correct sensor is connected to thatzone for example CO200.

Pre-alarm adjustment

ppm/LEL & auto/ manualreset selectors

Zone selectors

Explosive or Toxicselectors

Terminal block 1

Terminal block 2Continuous/pulsed main alarm

jumper

Printed Circuit board Layout

Select Toxic indication by moving switch 2 to the ONposition and switch 1 to the off position. In the abovepicture this shows zone 1 Toxic, zone 2 explosive, zone 3toxic, zone 4 explosive.

Pre-Alarm Sensitivity AdjustmentThe Pre-Alarm can be adjusted, in thecase of Natural Gas or LPG, from 8% to15% of the Lower Explosive Level (LEL).For Carbon Monoxide, it can be adjustedfrom 120ppm to 250ppm. Adjustment ismade using the pre-alarm potentiometermarked PT1. To increase the sensitivityturn the potentiometer away from thecentral point either left or right. i.e. Central Position is 15%LEL. Left or right 8% LEL.

Setting Main Alarm Memory functionThe Main Alarm thresholds are not adjustable and arefixed at 20% LEL for Natural Gas or LPG and 300 ppmfor Carbon Monoxide. The main alarm can be configuredto provide either a latching or an auto reset relayactuation. For example to turn off gas valves or to boostventilation in car parks or areas containing carbonmonoxide. Should gas be sensed in boiler roomslaboratories etc. the gas valve supplying the room will beturned off by the detector. This must only be manuallyreset following an alarm. However if the BX444 is beingused to control the levels of carbon monoxide in car parksas long as the ventilation is boosted and the levels ofCarbon Monoxide drop there is no requirement tomaintain the alarm so the unit can be allowed toautomatically reset.

IN CASE OF AN ALARM1 PUT OUT ANY NAKED FLAMES

2 CLOSE THE MANUAL GAS VALVE SUPPLYING THE PROTECTED AREA

3 DO NOT TURN ANY ELECTRICAL DEVICES ON OR OFF.4 OPEN ALL WINDOWS AND DOORS TO INCREASE VENTILATION

5 IF THE ALARM STOPS IT IS NECESSARY TO FIND THE CAUSE OF THE ALARM BEFORE ATTEMPTING

TO RESET THE DETECTOR. THIS MUST BE CARRIED OUT BY A RESPONSIBLE, QUALIFIED PERSON.6 IF THE ALARM CONTINUES AND THE CAUSE IS NOT EVIDENT OR POSSIBLE TO ELIMINATE, LEAVE

THE ROOM AND CONTACT YOUR GAS PROVIDERS’ EMERGENCY LINE. THEY WILL ADVISE

ACCORDINGLY.

The installation of this gas detector does not release the user from observing all the regulations concerningthe characteristics , installation and the use of gas appliances; the ventilation of the environment and theelimination of combustion products in accordance with local recommendations, regulations and byelaws.

For any damage caused to people, property or animals resulting from incorrect connection, installation orapplication of this gas detector Duomo will not be held responsible or liable.

This Gas detector is a safety device and therefore should only be maintained and installed by qualifiedpersons. To ensure correct function after installation Duomo provide a commissioning service using cali-brated test gases. For the service call 01905 797989.

Warning

To make the main alarm a latchingoperation, move switch 1 shown tothe off position. (This is the factorysetting).For an auto-reset function moveswitch 1 to the ON position. It isthen necessary for the BX444 to bereset in order for this change to take effect.Note: This setting should only be made by a qualifiedtechnician.

The BX444 can also be set to give a pulsed or continuousmain alarm function. This is mainly used to extend batteryback up time. For example, if a manual reset solenoidvalve is used to shut off the gas the 12V supply does notneed to be continuously applied. The valve will onlyrequire a triggerpulse to close it. Thissetting is made bymoving the jumpershown below to the Iposition. The factorysetting iscontinuous. It isagain necessary topress the reset toimplement thischange.

Setting Main Alarm Memory function

Faults - symptoms and solutions

When power is applied to the unit no lights or displays are lit.

Check the power supply.Check that the terminal plug on the reverse of the pcb is wired properly.Check that the terminal plug is pushed securely into the socket.

Fault light is illuminated and the BX444 is in alarm.

Has the correct number of sensors been selected on the p.c.b. See configuring the operation of the BX444.Is the green Light illuminated on the sensor?Check sensor connections.Is the connector plug in the sensor secure?Check that there is no interruption to the cable supply to the sensor.

The alarm function isn’t latching. When gas levels indicated drop below the main alarm threshold the mainrelay resets.

Check the position of the alarm function Switch. There are two modes. i) Auto reset ii) Latch with manual Reset.When you have selected the correct memory function you must press the reset button so that this change takeseffect. The main alarm relay changes over the volt-free relay and then with the Main Alarm light still on the relay re-energises.Check the position of the Jumper link JP1. This is located between the two terminal plugs. When in the ‘C’ positionthe relay will stay on, either until the level of detected gas drops if set for auto reset or until the level of gas dropsand the BX444 is manually reset. If the jumper is set to ‘I’position the relay will de-energise momentarily thenautomatically return to the on position. This function is used when the detector is connected to a manual reset valvewhich only needs a trigger pulse to close it. This also extends battery backup time as solenoid valves do not need tobe constantly powered. Check local regulations recommendations regarding manual reset gas valves and theircontrol.

Unit 5 Judge Court, North Bank, Berryhill Industrial Est. Droitwich, Worcestershire, England, UK, WR9-9AU

Telephone: 01905 797989 Fax: 01905 774296 email:sales@duomo.co.uk

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GuaranteeThis device is guaranteed for a period of 12 months from the date of purchase.

Conditions. Substitution free of charge of any component recognized as being faulty from production. The

unit must be delivered to the resaler or directly to Duomo.

KS21 Keystart Control Panel

The Duomo Gas Safestart is...a weep bypass assembly which proves that there are no gastaps open or serious leakages in gas pipe-work which relieson manually operated gas valves as the only means ofisolation.

Fact:Manual gas valves do get left on and will be operated byunauthorised individuals.

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