Electrical Contracting News (ECN) July 2017 - Page 35

FIRE DETECTION & SAFETY Understanding CO alarms Unlike the smoke alarm Code, BS EN50292:2013 offers more general, less prescriptive guidance on carbon monoxide alarms. It stresses that CO alarms are not a substitute for good installation and regular servicing of fuel burning appliances or cleaning of fl ues. Alarms can be either hard-wired mains or battery powered and may have an automatic end-of-life warning. In the Standard (and Building Regulations) the recommendation for CO alarms is determined by the presence of combustion appliances within the property being considered. However, unlike fi re, CO cannot be contained within a single property and can spread unnoticed to others adjacent which may not even have a combustion appliance. It can also be generated by sources other than combustion appliances. There is therefore a compelling case for CO alarms in all homes. Detect and alert Obviously, it is essential that carbon monoxide from the source reaches the alarm to trigger it and also that the alarm sounder can alert or wake occupants. BS EN50292:2013 recommends that: • Ideally, a CO alarm should be installed in every room containing a fuel burning appliance (or outside boiler rooms) and in other areas to give warning such as well used remote rooms and all bedrooms. • If this is not viable, CO alarms should be considered in any room containing a fl ue- less or open-fl ue appliance and where the occupants spend most time. Alarms should also be installed in rooms through which an extended and/or concealed fl ue passes. SPECIAL FEATURE Hard-wired alarms are easily installed in new builds, refurbishments and rewires, particularly alongside hard- wired smoke and heat alarms. Again, England and Wales fall well below these recommendations with Building Regulations Approved Document J requiring just a CO alarm in the same room as certain new or replacement fi xed solid fuel appliance. Again, occupiers and installers will benefi t from fi tting more alarms than this. Other national Regulations are much closer to BS EN50292:2013, covering all fuel types, but they all exclude appliances solely for cooking – unlike the standard. Mains CO alarms According to all the Regulations and BS EN50292:2013 alarms can be powered by batteries designed for the whole working life of the alarm or by mains. Hard-wired alarms are easily installed in new builds, refurbishments and rewires, particularly alongside hard-wired smoke and heat alarms. Together they can also offer extra safety features. For example, Kidde’s 4MCO and 4MDCO hard-wired CO alarms can be interlinked not only with each other but also wi