What to do if Duomo Gas Detectors are subject to repeated alarms?
If your Duomo Gas Detectors are experiencing repeated alarms, make sure there isn't an occasional gas leak. This could be due to a valve or joint that leaks when under pressure.
What to do if Duomo BX444-Mc are in main alarm but the main gas valve isn't closing?
If the Duomo Gas Detectors are in a main alarm condition but the main gas valve is not closing, verify that the connections are correct and that power is supplied to the valve, ensuring it's not stuck open. You can check the alarm relays' function by pressing the TEST button. Also, confirm that the main alarm action is configured for a latching alarm (Switch 2 on 5th DIP switch).
Why is sensor fault continuing to alarm in Duomo BX444-Mc?
If a sensor fault continues to alarm in Duomo Gas Detectors, it could be due to the red Overload LED being lit. Check the sensor wiring. If the red Overload LED is lit, it indicates a short circuit or overload on the sensor or the connecting cable.
How to fix Duomo BX444-Mc when one or all of the sensor fault lights are illuminated?
If one or all of the sensor fault lights are illuminated on your Duomo Gas Detectors, check that the plug is inserted correctly and that the sensor wiring is correctly terminated at both the sensor and detector. Also, ensure that 12V DC is present at the sensor, with the green light on the sensor illuminated. Pressing the TEST button allows you to check the efficiency of the device and verify if the sensors have been connected correctly.
How to troubleshoot no supply to the solenoid valve in Duomo BX444-Mc Gas Detectors?
If there's no supply to the solenoid valve in your Duomo Gas Detectors, remember that the Main Alarm relay is a volt-free contact. Therefore, 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.
How to fix Duomo Gas Detectors when no lights are illuminated?
If no lights are illuminated on the fascia of your Duomo Gas Detectors, check that the electrical supply is reaching the device and that the plug in terminal rail is pushed into place.
What to do if sensor is connected, but no LED is lit on the front fascia of Duomo BX444-Mc?
If the sensor is connected, but no LED is lit on the front fascia of your Duomo Gas Detectors, check that the DIP switch is set to the ON position.
The BX444-M is a wall or panel mounted microprocessor based gas detector control unit.
The controller has a built in sensor test delay that permits the main alarm relay to remain on during a gas test.
Carefully read the following instructions prior to installation of this device. Always keep this pamphlet for future reference.
The BX444-Mc is a safety device designed to give audible alarms and automatically provide latched electrical isolation of associated gas safety shut off valves.
The sensors must be mounted as shown below with the sintered head pointing vertically down.
Always check the wiring before powering up the system. Do not test this sensor with anything other than Duomo test gas.
Zone ON or OFF - The BX444-Mc will not look for a sensor on a given zone if the switch is moved to the OFF position.
Type of gas to be sensed. These are labelled as GAS or CO. Symbols refer to EN standard symbols.
Positive safety determines the condition of the main alarm relay and hence the operation of the gas valve.
Main Alarm relay actuation method. Configurable for latching or temporary alarm operation.
Determines whether the audible alarm remains operational after levels have dropped. In memory mode, the alarm remains and will need to be manually reset.
Configured to indicate oxygen levels. The function is determined by setting either excess oxygen or oxygen depletion on the sensor itself.
Details the power-up sequence, LED checks, sensor warm-up period, and manual TEST button function.
General| Detection Gases | CH4, CO, H2S, O2 |
|---|---|
| Detection Range (CH4) | 0-100% LEL |
| Detection Range (H2S) | 0-100 ppm |
| Operating Temperature | -20°C to +50°C |
| Power Supply | Rechargeable Li-ion battery |
| Sensor Type | Electrochemical |
| Alarm Setpoints | Adjustable |
| Display | LCD |
| Alarms | Audible, Visual, Vibration |
| Protection Rating | ATEX, IECEx |
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