Electrical Contracting News (ECN) July 2017 | Página 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