Civil Engineering Reference
In-Depth Information
All such systems, including the installation, wiring,
power supplies, panelling, etc., must comply with the
requirements contained in each of the parts to BS 5839.
A variety of mechanisms are used to display the
location of detectors, alarm points, etc. These indicators
may be via the use of text display, a light emitting indica-
tor or any such alternative approved device. Whichever
device is used each zone should be indicated in such
a way as it provides a simple 'at a glance' overview of
all zones, and where fi tted addressable information for
each detection call point unit. At each panel a clear plan
indicating the zones that are covered by the particular
panel should be displayed (see Fig. 9.80).
In a large proportion of buildings a simple evacu-
ation strategy will be adopted and on the operation of
a manual call point or detection by an automatic fi re
detector, fi re alarm sounders will provide warning and
indicate the need for a full evacuation of the building.
Larger more complex buildings may well operate a
phased evacuation strategy and the evacuation signal,
as has already been discussed, may be restricted to a
single fl oor or a limited area within the building. On these
occasions other areas may be provided with an 'alert'
warning signal.
Zones
- to support the above arrangements the
building will need to be divided into a number of alarm
zones in such a way that the fi re alarm sounders refl ect
an operation of a manual call point within that area or a
detector.
In order to achieve effective zoning the following
should be considered:
➤
Boundaries of every alarm zone, with the exception of
external walls, should be fi re resisting (compartment)
➤
Any overlap between signals and alarm zones
should not result in confusion (which zone has been
alarmed)
➤
A common alarm signal must be provided into each
alarm zone for evacuation and a different signal in
all the zones for an alert signal.
The manual alarm zones may incorporate more than one
detection zone but the detection zones cannot incorp-
orate more than one alarm zone.
Figure 9.79
Typical fi re alarm panel
BED 3
BED 4
BED 5
MAIN CONTROL PANEL
LOCATED HERE
BED 6
ZONE
02
STAFF
ROOM
FLAT 1
LIVING
ROOM
ZONE
03
ZONE
04
ZONE
05
BED 7
KITCHEN
BED 8
DINING
ROOM
BED 9
BED17
BED10
BED16
Phase 2 Phase 1
ZONE
01
ZONE
06
BED15
BED11
BED14
BED12
BED 23
Figure 9.80
Typical zone plan located adjacent to a fi re panel
