Duomo GS920 User manual
GS920 SeismicactivityNaturalGas&L.P.G.Detector
t: 01905 797989
FEATURES
■Seismic Activity
■Natural Gas or Propane detection sensor
■230V AC 50Hz Power Supply
■12V DC Battery backup option
■Catalytic Sensor Technology
■-10°C to +40°C Operating temperture
■IP42 Protective Rating
■CE Certied and approved to EN50194 & EN61779
■6 Year sensor lifespan
(in clean air and within operating temperature)
■2 Year Guarantee - 3 Year by Registering at duomo.co.uk
APPLICATION
The GS920 is a stand alone gas detector for detcting methane
or LPG sensor (specify at order stage) with an integrated seismic
detector that will shut o o a gas valve in the event of seismic
activity making it an ideal sensor in areas prone to earthquakes.
With a built-in relay the GS920 can be used to shut o a gas valve
in the event of a leak, or operate remote sirens and beacons to alert
those nearby of a potential hazard.
OPERATION
As gas concentrations exceed 10%LEL the relay on the unit will
actuate into an alarm state. Using a built-in 3-axis accelerometer,
the GS920 will shut o a gas valve and halt the gas supply when
seismic activity reaches 6 on the Modied Mercalli scale (or 60
-70cm/s2).
Stopping the gas supply in a building at this time is a valuable, and
potentially life-saving, exercise. Ruptured pipework due to buildings
shifting can cause undetected leaks and an increased risk of
explosion.
A further relay on the unit is pre-set to actuate at 10% LEL of either
methane or LPG. This relay can break the electrical connection to a
gas valve, or make a connection to an external waring device such
as an audible alarm or ashing beacon.
BATTERY CONNECTION
It is possible to connect this unit to a 12V DC battery to perform two
functions:
Firstly, It can be used to power the unit itself for up to one hour in the
events of mains failure.
Secondly, the battery can power a remote 12V DC manual reset
solenoid valve or siren, over 300mA.
GS920 Seismic Activity Natural Gas / Propane Sensor
SPECIFICATION
Power
Power Supply 230V AC 50Hz +/- 10%
Secondary Battery 12V DC - 1.2Ah +/- 10%
Current Consumption 2W @ 230V
Technical Specication
Earthquake Proof Sensor 6th degree of Mecalli scale
Gas(es) Detected L.P.G or Natural Gas
Sensor Technology Catalytic
Dimensions Width 115mm |Height 150mm |Depth 45mm
LED indicator Green: Power ON
Yellow: Fault
Red: Alarm
Mounting Wall Mounted or Embedded box
Alarm Threshold 10% of LEL
Working Temperature -10°C to 40°C
Functioning Humidity 0-90% Relative Humidity
Body Material ABS Self Extinguishing
Protective Rating IP42
Compatibility
Calibration Gas Compatibility Duomo Nat Gas / L.P.G Test Gases
Approvals, Certications and Guarantee
Approvals CE Certication: No.96125
Guarantee 2 Year as Standard
3 Year by Registering at www.duomo.co.uk
IP42
LPG
Natural
Gas
Seismic
activity
t: 01905 797989
GS920 SeismicactivityNaturalGas&L.P.G.Detector Precautions and Maintenence
Check the integrity of the unit after having removed it from the box.
Check that the data written on the box correspond to the type of gas used.
When doing the electrical connections, follow the drawing closely.
Any use of the detector for purposes other than the intended one is considered improper and as a result of which Duomo
(UK) therefore disclaims any responsibility for possible damages caused to people, animals or objects.
Do not allow the sensor to become wet.
The product is not waterproof either when immersed in water or exposed to high levels of humidity.
Every six months must perform a function check of the sensor and connected controller. Suitable test gas must be used
to avoid damaging the sensor. Disabling the sensor or the controller must be carried out by a suitably trained technician.
Every year a more accurate check must be performed by qualied personnel. Please call Duomo (UK) on 01905 797989
Overall Dimensions (mm)
Important Notes
IMPORTANT: Assembly / maintenance of the appliance must be carried out by qualied personnel and in
accordance with applicable laws and regulations including EN 60079-10.
The manufacturer assumes no responsibility for the use of products that have to comply with particular
environmental and / or installation standards.
IMPORTANT: Before connecting the equipment, it is recommended that you read the instruction manual
carefully and keep it for future reference.
Electrical Connections
IMPORTANT: Before connecting to the mains power, ensure the voltage is correct. Carefully follow the
instructions and the connections according to Regulations in force, keeping in mind that the signal cables should
be laid separate from the power cables.
115mm 45mm
152mm
RESET
ALARM
FAULT
GS920
METANO
METHANE
Antiseismic
ON
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Configuration and Testing
Important Notes
IMPORTANT: Assembly / maintenance of the appliance must be carried out by qualied personnel and in
accordance with applicable laws and regulations.
The manufacturer assumes no responsibility for the use of products that have to comply with particular
environmental and / or installation standards.
IMPORTANT: Before connecting the equipment, it is recommended that you read the instruction manual
carefully and keep it for future reference.
Electrical Connections
IMPORTANT: Before connecting to the mains power, ensure the voltage is correct. Carefully follow the instructions
and the connections according to Regulations in force, keeping in mind that the signal cables should be laid
separate from the power cables.
Configuring the GS920
The GS920 has two DIP switches on the PCB.The left switch is used to activate the intrinsic safety option.The right switch is
used to select a pulsed output to a connected gas valve. The GS920 can be congured to provide several modes of
operation.The congurable parameters are:
Switch 1 on the DIP switch
Intrinsic 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 aects how the gas valve operates and means that you may need to
change how it is wired to the GS920.
Example shows Zone 1 On.
Switch 2 on the DIP switch
Main alarm relay actuation method.This can be congured to provide either a continuous or a pulsed
output alarm operation, whilst gas is sensed. When the main alarm is actuated in an alarm condition,
if the switch is in the 'ON' position the relay is set to impulse functioning. Each pulse lasts about 30
seconds. Positioning the switch to 'OFF' the relay goes into continuous functioning mode, until the
gas level drops under the alarm threshold.
Example shows Zone 1 Explosive.
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
Power ON and Testing
Once the device has been turned on, the MAINS LED will blink for approximately 60 seconds, after which it will remain
ON.The GS920 will then be ready for detection.
Press the TEST button on the PCB to simulate a gas leak. The ALARM LED will light up and the relay will actuate after 5
seconds. After the alarm, the LED will turn itself o, the buzzer will stop and the connected appliances will be turned o. To
complete the test, issue gas from a pre-calibrated bottle of Duomo test gas.This test should be carried out at least once a
year. (Do NOT use a cigarette lighter to perform a test as this could damage the sensor).
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Connections and Wiring Diagram
Layout
ON
1 2
RESET
ALARM
FAULT
GS920
METANO
METHANE
Antiseismic
ON
1
2
3
4
5
6
7
8
1. Test Button - Only to be used in testing in laboratory by
qualied technician.
2. Catalytic Sensor - Sensor for Methane or LPG detection
3. Power On - Intermittent when system in test mode.
Static when fully operational.
4. Fault - Illuminates when sensor is not functioning
correctly and should be replaced. After 6 years this will
ash continuosly and beep every hour.
5. Alarm - Will illuminate when Methane or LPG
concentration exceeds 10% LEL
6. Reset - Reset the GS920
7. Micro switches - Switch 1 turns Positive Safety option
ON or OFF. Switch 2 changes the unit between pulsed
(ON) and continuous (OFF) functioning mode.
8. Terminal connections - See wiring diagram above
345 6 7 8
Power Supply
230V
3A Max. Fused
and Isolated
Supply 230V Solenoid
valve NC
(normally closed)
N
Ph
12V DC
1 2
12V DC Solenoid
valve NC (normally
closed) 600mA
max.
345 6 7 8
Power Supply
230V
3A Max. Fused
and Isolated
Supply Intrinsic safety 230V
Solenoid valve NC
(normally closed)
N
Ph
12V DC
1 2
C
NC
NO C
NC
NO
With Positive Safety
switch on
Typical 12V DC
connection
With Positive Safety
switch o
345 6 7 8
12V DC
1 2
12V DC Solenoid
valve NO (normally
closed) 600mA
max.
Power Supply
230V
3A Max. Fused
and Isolated
Supply
N
Ph
With pulsed output
switched on
345 6 7 8
12V DC
1 2
C
NC
NO
C
NC
NO
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RESET
ALARM
FAULT
GS920
METANO
METHANE
Antiseismic
ON
RESET
ALARM
FAULT
GS920
METANO
METHANE
Antiseismic
ON
RESET
ALARM
FAULT
GS920
METANO
METHANE
Antiseismic
ON
Sensor Orientation
The GS920 must be mounted as shown below pointing vertically down.
Sensor Positioning
The GS920 sensor should be mounted in accordance
with certain considerations. Do not position next
to burners, heaters or ovens where temperatures
above the room ambient may be experienced. It is, if
possible, better to mount the sensors on the opposite
wall. This is, of course, dependant on the size of the
protected area.
Natural gas is lighter than air and will therefore rise,
meaning the GS920 sensor should be mounted 30cm
from the ceiling of the protected area.
LPG is heavier than air, therefore the GS920 sensor
should be mounted 30cm from the lowest point on
oor of the protected area. Natural Gas is lighter than
air and the GS920 should be mounted 30cm from the
highest point from ceiling of the protected area.
If you require assistance regarding locating sensors
please call our Droitwich factory on (01905) 797989
Important Notes
Always check the wiring before powering up the system.
Do not test this sensor with anything other than Duomo test gas. Concentrations above this will damage the sensor and
shorten sensor life.
The installation of this gas sensor does not release the user from observing all the regulations concerning the characteristics
of the installation and use of gas appliance, the ventalation of the protected environment and the removal of the products
of combustion. Duomo (UK) 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 sensor.
To ensure correct function after installation Duomo provide a commissioning service using calibrated test gases. For this
service call +44 1905 797989.
t: 01905 797989
Still experiencing difficulties?
If you have made the checks above and are still experiencing diculties then please call Duomo (UK) Ltd on
+441905 797989 for technical assistance.
Troubleshooting
The Problem The Solution
The sensor does not power up Check that the 12/24 VDC power is present, and that positive and negative polarity has not been
inverted.
The fault LED is illuminated
If the yellow fault LED remains illuminated check if a 5 year peroid has elapsed since installation
date. If the LED is blinking check if the earthquake proof sensor has been triggered. To reset, press
the reset button.
The detector is repeatedly issuing an alarm Check that there are no gas leaks. If the fault light is also illuminated, proceed as in the previous
paragraph
The detector does not shut o connected
devices when going into alarm state.
Check wiring is correct and that the jumper that carries the power to the relay has been set properly.
All relays must be free from electrical power. Check the connection drawing.
Connected Solenoid valve is not operating
well
Check that nothing is draining power. Direct connection to the GS920 is not permitted for 12V DC
solenoid valves or sirens with power demand higher than 300mA. To connect a solenoid valve with
a higher power demand you have to use a battery. You can connect a pulsed 12V DC reset solenoid
valve.
This is a working document and will be updated as new troubleshooting and FAQs become apparent. If your issue is not listed here please
call Duomo (UK) on 01905 797989 and inform us so we can list your issue and associated solution here.
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, qualied 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 valves to the area and contact your gas provider emergency line. They will advise accordingly.
t: 01905 797989
Commisioning
It is strongly recommended that this SGM595 gas sensor and connected detection system is commissioned and serviced
by Duomo Commissioning Engineers or engineers approved by Duomo. A quotation for commissioning or service will be
provided upon request.
Email site details and preferred date for commissioning or service to [email protected] to the Duomo Service Department.
Or call +44 1905 797989
The benets of this equipment being commissioned by Duomo are:
• On board spares - If for whatever reason this equipment doesn't function correctly Duomo engineers will have spares
on board to ensure that the commissioning is successful.
• A Duomo Commissioning Certicate is provided - A certicate from the original maufacturer ensures that the commisioning
or servicing carried out is at a high professional standard by a competent and qualied service engineer.
It is prudent to make electrical connection to the detector terminal plus when withdrawn and leave the plug o the detector
so that the Duomo Engineer is the rst to power up the unit on site. This allows wiring to be checked prior to commissioning
and avoids damage due to incorrect connection. Guarantees for this product will become void if damage is caused by the
installer.
Maintenence
This sensor must be function checked as described above using calibrated test gas every 6 months.
To arrange for a Duomo engineer to conduct this work or to arrange a service contract please call +44 1905 797989.
Commisioning, Service & Maintenence
Notes
www.duomo.co.uk
sales@duomo.co.uk
01905 797989
5 The Furlong, Berry Hill Industrial Estate, Droitwich, Worcestershire, WR9 9AH
@DuomoUK
linkedin.com/company duomo-uk
GS920 24102019 rev1
This document is protected by copyright ©
No changes by others are permitted without prior authorisation by Duomo (UK) Ltd.
Duomo (UK) Ltd reserve the right to modify and revise this datasheet without notication.
GAS SAFETY CONTROLS
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