The SD-503ST stand-alone combined smoke and heat detector
MLW5550
3
1
The SD-503ST Stand-alone combined smoke and heat
detector
The SD-503ST is used to detect fire hazards in the interior of
residential or commercial buildings. The detector can be installed in
mobile homes or caravans. The product is not designed to be installed
in industrial premises.
The detector indicates a fire hazard using the built-in LED indicator
and acoustic signalling.
The SD-503ST consists of two independent detectors – an optical
smoke detector and a heat detector. The optical smoke detector works
on the principle of scattered light. It is very sensitive to large dust
particles which are present in dense smoke. It is less sensitive to
smaller particles generated by the combustion of liquids such as
alcohol. That is why the fire detector also contains a built-in heat detector
which has a slower reaction but is much better at detecting fire which
generates only a small amount of smoke.
Detector range and location
The smoke detector must be installed so that any smoke easily drifts
into the detector owing to natural thermal currents, e.g. on the ceiling. It
is suitable for residential buildings but not suitable for free spaces,
outdoor environments or interiors with extremely high ceilings (above
5 m) where fire by-products can disperse over a large area – the
smoke would not reach the detector position.
The detectors should be installed by a trained technician with a valid
manufacturer’s certificate.
Detectors should be installed in the building according to the project
documentation. If such documentation is not available, the detector
positions should comply with the effective standards for fire alarm
signalling systems.
The detector must always be placed in the section leading to the exit
of the building (escape route), see
Fig. 1
. If the building has a floor
area greater than 150 m
2
, installation of an additional detector in some
other suitable place is required, see
Fig.2
.
1. kitchen,
2. living room,
3. – 6. bedrooms
/
/
basic
coverage
/
/
recommended
coverage
Fig 1
Fig 2
Fig 3
In multi-storey flats and family houses the detector should be
installed above the stairs. It is recommended to place additional
detectors in rooms where people sleep. See
Fig 3
.
Installation on level ceilings
Place the detector in the centre of the room if possible.
The detector
must not be recessed into the ceiling
due to the possible existence
of a cool air layer on the ceiling.
Never place the detector in the
corner of the room
(always keep at least 0.5 m distance from the
corner - see Fig 4). There is an insufficient circulation of air in the
corners.
Installation on sloping ceilings
If the ceiling is not suitable for mounting on a level surface (e.g. a
room under a roof ridge), the detector can be installed as in Fig. 5.
Fig. 4
Fig. 5
centre of the room, best location
acceptable location
Walls, partitions, barriers and lattice ceilings
The SD-503ST detector must not be installed closer than 0.5 m
from any wall or partition.
A narrow room with a width of less than 1.2 m
requires the detector(s) to be placed at a distance of at least one third of the
room’s width away. In a case when a room is separated into sections with
furniture, racks or semi partition walls which do not reach the ceiling, the
space is considered to be fully separated if the gap between the top of
these and the ceiling does not exceed 0.3 m
.
A free space of at least 0.5 m
is required under and around the detector. Any irregularities of the ceiling
(e.g. girders) exceeding 5 % of the ceiling height should be considered a wall
and the above mentioned limitations should apply.
Ventilation and air circulation
The detectors must not be installed directly by ventilation or air
conditioning vents.
In the case of air being supplied through a
perforated ceiling, each detector must be placed so that no perforation
hole occurs within 0.6 m of the detector.
•
Avoid installing the detector in the following locations:
•
places with poor air circulation (niches, corners, apexes of A-
shaped roofs, etc.)
•
places exposed to dust, cigarette smoke or steam
•
places with over-intense air circulation (close to ventilators, heat
sources, air conditioning outlets, etc.)
•
in kitchens and other cooking places (because steam, smoke or oily
fumes can cause false alarms or reduce detector sensitivity).
•
beside fluorescent lights or energy-saving light bulbs (electrical
interference can cause a false alarm)
•
in areas with lots of small insects
Warning:
Most false alarms are caused by improper detector
location.
See CEN/TS 54-14 standards for detailed installation guidelines.
Installation
When installing the detector, abide by the procedures recommended
in the previous paragraphs.
Fig. 6:
1– detector cover opening; 2 – detector cover closing; 3 – optical status
signalling (red LED); 4 – arrow showing where to insert the detector;
5 – configuration terminals; 6 – battery holders;
1.
Open the detector cover, by turning it anti-clockwise (1)
2.
Attach the plastic base to the selected place using screws
3.
Use the terminals (5) to set the required detector function
–
see the table below
