Gas Alarm GX-C300S Carbon Monoxide Detector + External Sensor

The professional CO detector with external sensor for town and natural gas: monitor carbon monoxide and fuel gas simultaneously and shut off the hazard source

The Schabus PROFI CO Detector GX-C300S is a professional warning device for carbon monoxide (CO), combined with an external sensor for town and natural gas. Inside the device is an electrochemical CO sensor that has been fully tested to DIN EN 50291 by TÜV Süd. The enclosed external gas sensor GX-SE detects methane, butane, propane and ethanol and can be optimally positioned independently of the control unit. Thus a single device monitors both life-threatening carbon monoxide from combustion appliances and gas boilers as well as escaping fuel gas.

A 2-line plain-text display continuously shows the operating status and the CO concentration accurate to the ppm. In the event of an alarm the GX-C300S warns for CO as well as for gas acoustically and optically and at the same time switches a potential-free changeover relay. This allows the hazard source to be shut off: the relay can close a solenoid shut-off valve, de-energise the heating system or trigger forced ventilation. A second potential-free changeover relay reports technical faults to the building management system or home automation. An intelligent sensor system helps to avoid false alarms.

The GX-C300S is intended for living rooms and rooms with residential-like use and is particularly suitable for boiler and utility rooms, gas boiler rooms, boiler plant and technical rooms, but also for occupied rooms in combined heat and power plants and biogas plants as well as open gas cooking stations in the catering trade. The name says it all: when the 300 ppm threshold is reached, the system alarms immediately.

Two hazards, one device

The GX-C300S combines a standard-tested CO sensor with an external gas sensor, two relay outputs and a plain-text display.

What is included in the box

The device is ready for immediate use. The external sensor is already connected.

• GX-C300S CO warning device with pre-assembled cable in PG cable gland to the external GX-SE sensor for town and natural gas (methane, butane, propane, ethanol)
• Operating instructions GX-C300S and instructions for the SE sensor
• 1 small and 4 large screws with matching wall plugs
• PG cable glands: 1 small (for Re2) and 2 large (for Re1 and 230 V~)

The device has no options and no additional variants.

How the GX-C300S is constructed

The control unit with CO sensor, evaluation, display, alarm generator and relays sits in a housing on the wall. The gas sensor GX-SE is mounted separately at the desired location and is connected via a pre-assembled cable.

CO alarm to standard, gas alarm and shut-off

The alarming of the CO sensor follows the requirements of DIN EN 50291.

The alarm cannot be acknowledged. Only the acoustic alarm can be muted with the RESET | TEST button. When the concentration falls below the alarm limits, the device automatically returns to monitoring mode.

Alarm delay times to DIN EN 50291

DIN EN 50291 specifies alarm delay times depending on the gas concentration. During development of the sensor the lower limit of the times was taken into account.

• At 30 ppm no alarm may occur within 120 minutes
• At 50 ppm no alarm may occur within 60 minutes; the device alarms at the latest after 90 minutes
• At 100 ppm no alarm may occur within 10 minutes; the device alarms at the latest after 40 minutes
• At 300 ppm the device alarms at the latest after 3 minutes; on reaching the threshold immediately. Hence the type designation GX-C300S

Display indication: at 0 ppm “CO: Ready” is shown. In accordance with the standard no value is displayed below 30 ppm; the exact value also below 30 ppm is shown in the service menu under “CO Sensor”. From 30 ppm the ppm-accurate value appears; on alarming “Alarm”.

Mount correctly and put into operation

The control unit and the external sensor are mounted at different locations, each appropriate to the gas being monitored.

Wall mounting of the GX-C300S

1. Loosen the four housing screws and remove the front panel. If necessary, unplug the ribbon cable from the connector.
2. Mount the base shell of the housing on the wall with the enclosed screws and wall plugs.
3. After installation, plug the ribbon cable firmly back in and screw the front panel on.

Position of the external gas sensor GX-SE

• For natural gas (methane, CH4): on the wall, about 30 cm below the ceiling
• For liquefied or bottled gas (butane, propane): on the wall, about 15 to 30 cm above the floor
• Route the cable to the desired sensor position and fasten the sensor to the wall with the enclosed screw and wall plug
• Insert the RJ plug into the sensor until it clicks; the cable is already pre-assembled
• Further information on the mounting position is given in the enclosed sensor instructions

Mains connection 230 V

After opening the housing the safety cover (High Voltage) must be removed. The cable from the house connection is led through the PG cable gland at the front of the housing and screwed to the terminals L, N and PE. These are always provided twice and interconnected.

Connection of the potential-free relays

• Re1 (alarm) and Re2 (fault) are potential-free changeover contacts with contacts C (common), NC (normally closed) and NO (normally open)
• The switching current of 5 amperes must never be exceeded
• In monitoring mode the relay is energised (NO closed, NC open)
• In alarm or fault mode the relay drops out (NO open, NC closed)
• Details of the connection are given in the installation instructions of your gas heating or the solenoid shut-off valve used

Commissioning

1. Apply mains voltage. A short electrical function test is performed; the display greets you with the manufacturer’s name and the device type. During this time all self-tests of the CO sensor are completed.
2. Then the main display appears and the warm-up time of the external gas sensor starts (“Preheating”). After around 3 minutes the warm-up time is finished and the display reports “CH4: Ready”.
3. If the green LED lights alone, the device is ready for operation. The warning system now monitors the room and can remain in continuous operation for years without restriction.

Even after a short power failure the function test is started again.

Display information and self-monitoring

• Main display: “CO: Ready” and “CH4: Ready”, in addition “Preheating”, “Fault”, “Alarm” or “Replace me” for the gas sensor
• CO Sensor: ppm-accurate CO indication
• Sensor Test @: shows how much time has passed since the last sensor test
• Last Error: number of the last fault, see error codes

With each press of SERVICE you go to the next display until the main display appears again. If you remain on a display, the device automatically returns to the main display after 5 minutes (after 8 minutes on the CO ppm display), likewise if you hold SERVICE pressed for about 8 seconds.

Self-tests in the background

The built-in 32-bit microcontroller continuously monitors the system at around 300 points within the device. The values of various temperatures, voltages and currents are measured and compensated, partly stored for internal long-term tests, calculated with one another and some of them displayed on the display. The system performs tests on the sensor element every 24 hours; they run in the background. If the self-test is rated “not good”, the system performs up to three restarts, repeats the measurements and then decides whether a fault message is issued.

Note for maintenance companies

It is recommended that at every check all data are entered in a list with date and time. In this way conclusions can be drawn about the operational safety of the installation and any manipulations.

Test the alarm generator regularly

For your safety the manufacturer recommends regularly checking the acoustic alarm generator with the test button for proper function.

How to check the GX-C300S

1. Press the RESET | TEST button for a few seconds.
2. The LEDs light or flash, the alarm generator sounds and both relays Re1 and Re2 drop out.
3. Check whether connected devices such as solenoid shut-off valve, heating or building management system react as intended.

The correct operation of the sensor should be tested about every 3 months with suitable test gas.

Behaviour in the event of CO and CH4 alarm

1. Ventilate the room and by switching off the CO source ensure that no further carbon monoxide can escape. In the event of a CH4 alarm, by shutting off the gas source ensure that no further gas can escape. Inform other persons and ask everyone to leave the room.
2. Remain calm, open all doors and windows, take all combustion appliances out of operation; on gas appliances operate the emergency shut-off valve. Do not operate possible ignition sources. Provide fresh air.
3. If the alarm continues or occurs again, evacuate the building and leave all windows and doors open. Ensure that all persons in the building are warned.
4. Seek medical help for anyone showing symptoms of carbon monoxide poisoning and point out that inhalation of carbon monoxide is suspected.
5. If necessary call the emergency number of the supplier of your heating or gas installation so that the source of the release can be identified and eliminated.
6. Only put the combustion appliance back into operation when a competent person has checked it and released it for use.

Faults, error codes, sensor replacement and care

Recognising a fault

• Fault relay Re2 drops out; the building management system or home automation is informed
• The yellow “Error” LED flashes or lights up
• A short beep sounds every 10 seconds
• Press SERVICE repeatedly until the display gives information on the type of fault. Under “Last Error” there is a number that you quote to the technical support of Elektrotechnik Schabus, who will find a solution together with you

Few faults affect the measurement of the CO concentration and prevent alarming in the event of danger. There are, however, some faults that do not affect the warning system and merely indicate adverse ambient conditions with accelerated ageing or mains voltage fluctuations. The flash rhythms of the yellow LED are controlled by the microcontroller. If this itself has a problem, the yellow LED lights continuously. A controller problem can only be remedied at the manufacturer’s works in Stephanskirchen.

Error codes under “Last Error”

• 1: internal supply voltage too low
• 2: mains supply too low
• 3: sensor or sensor cable defective
• 4 to 9: the yellow, red or green LED cannot be switched on or off
• 10 and 11: internal output fault
• 12: sensor test failed
• 21: memory initialisation failed, yellow LED flashes slowly
• 22: internal software error, yellow LED flashes slowly
• 23: ambient temperature too low, yellow LED lights continuously
• 24: ambient temperature too high, yellow LED lights continuously
• 25: sensor test failed, yellow LED flashes rapidly
• 26: temperature sensor fault, yellow LED flashes slowly
• 27: memory error detected, yellow LED flashes slowly

For codes 1 to 12 there is no special LED indication.

Remedying faults

• Press the RESET | TEST button so that fault relay Re2 is energised again
• Only in the event of a new fault of the same or a different type does Re2 drop out again
• Most faults remedy themselves or when the device is disconnected from the power supply, allowed to cool for about 15 minutes and then restarted
• If there is no improvement, contact technical support

Maintenance and sensor replacement

The GX-C300S operates maintenance-free. Free the sensor and device of dust from time to time and use only dry cloths for this purpose. Keep the external sensor in particular free from moisture at all costs. The service life of the CO sensor depends on temperature and humidity: it is up to 10 years at a maximum of 28 °C and a minimum of 30 % rH, up to 6 years at a maximum of 40 °C and a minimum of 40 % rH.

After 5 years of operation the external gas sensor GX-SE must be replaced. The display then reports “CH4: REPLACE ME”.

1. Switch the device off or de-energise it and replace the sensor.
2. Switch the device on again and wait for the warm-up time (“Preheating”).
3. Confirm the sensor replacement by holding the SERVICE button pressed for 8 seconds on the main display.

Cleaning and care

• Avoid the influence of moisture (splash or rainwater), dust and direct sunlight on the device
• Clean only with a dry linen cloth; in the case of heavy soiling it may be slightly dampened
• Do not use solvent-containing cleaning agents

Manufacturer’s notes

• Read the operating instructions carefully before installation and commissioning and keep them; they form part of the product
• Installation must be carried out by a qualified specialist; please observe the five safety rules
• Install only in dry indoor areas on a wall
• Do not use in potentially explosive areas
• The device is not approved for any use other than that described
• Intended for residential buildings and living areas, sales areas such as shops and hypermarkets and rooms of small businesses such as workshops and service centres; all places of use are connected to the public low-voltage network
• All connection cables must be permanently installed as surface-mounted cables
• The cable to the external sensor must not be extended
• Keep the external sensor free from moisture at all costs
• Packaging material is not a children’s toy and does not belong in children’s hands
• The CE declaration is available for download on the manufacturer’s website

Statutory warranty, guarantee and disposal

The GX-C300S is covered by the statutory warranty of at least 2 years in the EU. The manufacturer Elektrotechnik Schabus additionally offers a 5-year guarantee that can be registered online. Repair and spare parts are available directly from the manufacturer, even beyond the statutory warranty. A prerequisite is that the device has been used in accordance with the operating instructions. The manufacturer accepts no liability for damage caused by accident, misuse, modification or negligence.

The GX-C300S does not belong in household waste. The crossed-out wheeled bin symbol on the product reminds you to use the take-back systems for waste electrical and electronic equipment (WEEE Reg. No. DE91394868). In this way the materials can be reused in an environmentally friendly manner at the end of the service life. Information on collection, reuse and recycling systems is available from the waste advisory service of your city or from the manufacturer.

Why the GX-C300S is suitable

Areas of application

• Boiler and utility rooms with gas transfer point
• Gas boiler rooms and boiler plant
• Technical rooms and buildings with solenoid shut-off valve
• Occupied rooms in combined heat and power plants
• Biogas plants
• Open gas cooking stations in the catering trade
• Utility rooms with gas cylinders and heaters
• Interlocking of the gas supply in the event of CO or gas release
• Connection to building management system and home automation

The Schabus PROFI CO Detector GX-C300S: CO detected, hazard averted.

Frequently asked questions