The Association of Swiss Installers of Security Systems (SES) has established the following guidelines:
For the monitoring of flammable and explosive gases, such as Methane CH4, Ethanol C2H6, Propane C3H8, Butane C4H10, Pentane C5H12, Hexane C6H14 and Hydrogen H2, the following points should be observed:
Number of gas sensors
- At least two gas sensors must always be used in each room
- The maximum monitoring area per gas sensor is 60 m2
- The maximum distance from gas sensor to gas sensor must not be more than 10 m
- The maximum distance from the gas sensor to a wall must not be more than 6 m
- In corridors or rooms less than 3 m wide, the distance from gas sensor to gas sensor may not exceed 15 m
Installation of gas sensors
- For gases with a density lower than air, the gas sensors must be mounted on the ceiling. For example: Hydrogen H2, Methane CH4 etc.
- For gases with a density greater than air, the gas sensors must be mounted 30 cm above the floor. For example: Ethanol C2H6, Propane C3H8, Butane C4H10, Pentane C5H12, etc.
- Special clarifications are required for certain gases. If in doubt, please contact us.
Installation of the gas control panel
- A gas control panel should always be installed outside of the danger area.
- A gas control panel should be in an easily accessible location.
- A gas control panel for flammable (explosive) gases must be backed up by a UPS.
- The emergency power supply (UPS) for gas warning systems must ensure operation for at least 2 hours.
Servicing the gas warning system
- Gas warning systems must be put into operation by the installer.
- The gas measuring cells in the gas sensors are wearing parts and must be replaced every 1-5 years, depending on the type of gas.
- A gas warning system must be checked and calibrated by the installer at least once a year. Depending on the application, shorter intervals may be necessary.
- When servicing a gas warning system, the gas measuring cells must be replaced in accordance with the maintenance plan.
For more information, please contact the association and order their documentation: