Specifications

4
The only restrictions to the correct operation of a Smoke Alarm system in a fire situation are: that
there are a sufficient number of alarms in the system, sufficient smoke reaches the alarms, they
are correctly installed and sited, and that they are regularly maintained and tested for correct
operation. If all of these factors are right, there is a very high probability that sufficient warning
will be given in life-threatening situations caused by a fire.
FITTING
We recommend the use of 1mm 6243Y 3 core and earth PVC insulated cable to BS6004 standard.
Building Regulations and
BS 5839: Pt.6 state that when using mains only alarms, they should be
wired from a dedicated circuit at the distribution board. If mains alarms with a back-up supply are
used, it is acceptable to wire them from a regularly used lighting circuit. In both cases, all hard
wired alarms should be on a single final circuit.
Use the third core of 6243Y cable as stated above. Do NOT use the earth wire of twin and earth
cable as this could cause problems of mistaken identity at a later date.
A junction box is required to make the electrical connections to comply with IEE Wiring Regulations
and a standard back box can be used with the 150 series alarms, but we would recommend the
purpose built Surface Mounting Kit Ei157 to provide an easier and more attractive option. The 140
and 160 series Smoke and Heat Alarms have an Easi-fit mounting plate, so no back box or
mounting kit would normally be required.
All of the Ei alarms are designed for ceiling mounting and will under most circumstances perform
better if sited in this position. If it really is not practical to mount them on the ceiling, a Smoke
Alarm can be wall mounted with the top edge 15-30cm from the ceiling. Ensure that it is 30cm
away from any corner or obstruction which may impede the movement of smoke to the alarm.
Do not wall mount heat alarms.
We recommend that under normal circumstances Smoke and Heat Alarms should only be
interconnected within the confines of a single family dwelling. If they are connected between
different units, there may be excessive nuisance alarms and it can be difficult to locate and silence
the unit causing the alarm. However, there is no technical reason why up to 20 alarms (providing a
relay is not used) cannot be interconnected in a single system that encompasses a number of
individual dwellings - such as may be required in an HMO, for instance. In circumstances such as
these, a very high level of system design, management and maintenance is necessary to reduce
the level of nuisance alarm. The minimum requirement should be to install an Alarm Locator Switch
Ei159 on each floor of the property. By pressing this switch, all alarms in the system are silenced,
for a period of approx 8 - 10 minutes, except for the unit initiating the alarm state. This allows
time to rectify the problem before the system is automatically reinstated to full working order.
14. Can I fit the
Smoke or Heat
Alarm on
the wall?
10. Will they
always work?
11. What cable do
I need for the
Mains connections
and where should
the supply be
taken from?
12. What cable do I
need for the
interconnect line?
13. How do I mount
the Alarms on
the ceiling?
15. How many
Smoke and Heat
Alarms can I link
together?