The JA-80S wireless fire detector
MHS51500FCC
1
The JA-80S wireless fire detector
The JA-80S is a component of Jablotron’s Oasis 80 alarm system. It
is designed to detect the presence of fire inside residential or
commercial buildings. It should not be installed in industrial premises.
The battery-powered detector communicates via OASIS radio protocol
and has a built-in local warning siren.
The detector combines an optical smoke sensor with a heat sensor.
Both sensors have their outgoing signals processed digitally, resulting
in higher false alarm immunity. The optical sensor works using a light
diffusion principle and is very sensitive to the presence of large-sized
particles which are characteristic of dense smokes. By contrast, the
sensor is less sensitive to small-sized particles which are typical of
cleanly burning fires. In particular, the smoke sensor is not capable of
detecting the by-products of cleanly-burning fluids such as alcohols, for
instance,. This deficiency is compensated for by the built-in heat
sensor. This sensor provides a slower reaction when compared to the
smoke sensor, but is much better at reacting to fires with rapidly rising
heat producing only a little smoke.
Exposing fire conditions to the smoke and heat sensors requires
some level of air circulation. It is therefore necessary to install the JA-
80S detectors in such a place on the ceiling that (in the case of fire)
smoke masses are forced to go in the direction of the detector’s
position. This can usually be achieved in most buildings. However, the
JA-80 is not suitable for installation in outdoor spaces or interiors with
an extremely high ceiling where fire by-products would not reach the
detector position.
Detection range, detector positioning
The following table shows the detector’s working range in relation to
the height of the ceiling on which the detector is installed. The range is
expressed as the radius of the circular fire detection area for a detector
installed on a ceiling directly above .
Ceiling height (m)
< 4.5
4.5-6
6-8
8-11
11-25
> 25
Smoke
detection
7.5* m 7.5* m
7.5* m
7.5* m
Not suitable
Not
applicable
Heat
detection
5* m
5* m
5* m
Not
suitable
Not
applicable
Not
applicable
Not applicable – meant for a particular ceiling height range
Not suitable –not usually used in such cases
* – the radius of the detection area below the detector
Installation on a horizontal level ceiling
Due to the possible occurrence of a cold air layer right under the
ceiling, the detectors must not be imbedded into the ceiling. The
distance between any point to be protected and an imaginary vertical
line from the detector down to the floor must not exceed the radius
indicated in the table.
Installation on a sloping ceiling
If the JA-80S is installed just under an apex formed by the joining of
two sloping ceilings the values indicated in the table can be increased
by 1% for every degree of slope up to a maximum of 25%. If the
space to be protected is under a saw-tooth type of roof, JA-80S
detectors should be installed under each apex. However, a roof with a
shallow saw-tooth form can be acceptable if the height difference
between the highest and lowest parts of the ceiling does not exceed
5% of the total ceiling height.
Walls, partitions, obstacles, and trussed ceilings
The JA-80S must not be installed closer than 0.5 m from any
wall or partition. A narrow room with a width of less than 1.2m
requires the detector(s) to be placed at a distance of at least one third
of the room’s width away. In the case of separating walls (partitions,
warehouse objects) which do not reach the ceiling, the space is
considered to be fully separated if the gap between the top of the
separating wall and the ceiling does not exceed 0.3 m. A free
space of at least 0.5m is required under the detector. Irregularities in
ceiling shape which do not exceed 5% of ceiling height are considered
insignificant – the ceiling can be regarded as being even and limits
from the table are applicable. However, any irregularity (including
beams) exceeding 5% of the ceiling height is considered to be a
wall with the consequences stated above.
Ventilation and air circulation
The detectors must not be installed directly by a fresh air inlet,
e.g. 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 0.6m of the detector.
Avoid installing the detector in the following locations:
•
Places with poor air circulation (niches, corners, apexes of A-
shaped roofs).
•
Places exposed to dust, cigarette smoke or steam.
•
Places with over-intense air circulation (close to ventilators, heat
sources or air conditioning outlets).
•
Kitchens and other cooking places (because steam, smoke or oily
fumes can reduce detector sensitivity).
•
Places close to metal objects (which can cause radio
communication screening).
Caution: The most common reason for the detector to be
accidentally triggered is improper detector location.
open
c
lo
s
e
test
button
with LED
Installation
Take the following steps:
1. Open the detector (rotate the rear cover)
2. Screw the rear cover onto the desired location
3. Leave the battery disconnected and the cover open and then
follow the control panel or receiver manual.
4. The basics of enrollment are:
1. Enter enrollment mode on the control panel by keying in “1” in
Service mode.
2. Install a battery into the detector to activate enrollment and self-
calibration (20 secs) which should be done in clean air without
smoke or fumes at a temperature of about +20°C.
3. Exit enrollment mode by pressing “#”.
4. To enroll a detector after having already connected a battery,
first disconnect the battery, and press and release the test
button to discharge any remaining charge to ready the device
for enrollment.
5. After closing the detector, check that the two halves of the
housing are securely together.
After installing a battery into the detector, allow one minute for
stabilisation. During this minute the LED is continuously lit.
Jumpers
Fire
Instant
SIREN ON / OFF allows the built-in siren to be disabled (OFF =
disabled)
FIRE / INST selects what the natural reaction of the control panel to
the detector signal will be.