Fire alarm on:
If applicable for the system, this type
of input is connected to a thermal fire
detector or with the output of a fire
detection central. In case of a fire,
not only will the fire detection system
notice the fire, but also the burglary
detection will probably switch into
alarm mode, this because of the
incorrect information received from
e.g. the PIR-sensor detecting the
moving heat from the fire or any
people entering the premisis.
In case of a fire, most probably there
will be also a fog expulsion. This
type of input will prevent this
awkward and unwanted situation.
Properties of the ‘fire alarm on mode’:
4
The unit will in any circumstances refuse to perform a fog expulsion. Even an eventual
panic input will be totally ignored.
4
The moment the fire alarm mode is active, the unit will sound through its internal siren.
The volume of this temporary warning can be set.-
;
speaker -
;
fire siren.
4
If a fire alarm mode output is set, this output will be active as long as the fire mode is
valid.
4
If the “fire alarm on” input is selected with a voltage edge (pulse) operation, it is
necessary to select also an input as “fire alarm off” to be able to switch off the fire
alarm mode by p.e. key switch.
4
The blocking of the fog expulsion will be only removed when the unit is subsequently
switched into guard mode.
Activation of the fire alarm on input:
Depending on the software settings, this input can start the fire alarm mode when:
- A negative or a positive voltage edge (pulse): an active puls will switch on the
fire mode. Following pulses have no influence. The software is going to force you to
select also a “fire alarm off input”. This input is described on next page (p17).
- An active voltage level (0 or 12 V): As long as the voltage is active, the fire mode will be
active. The setting of a “fire alarm out” input is not required. However, if there were
selected a ‘fire alarm out’ input, the status of this input would depend on the ‘off status’
of the fire alarm on mode. See next page (p 17)
i
Thermal fire detector
Common used fire detectors can be stated in 3
major categories:
- Optical fire detector: is in fact a smoke detector.
Smoke changes the light reflection properties of
the air. This changement in light reflection will be
noticed by an opto-electronic transmitter-receiver
and reported as a smoke detection. Reacts on
fog expulsion and causes fals smoke alarms.
- Ionic fire detector: is in fact also a smoke detector.
Smoke contains chemical waste particles, which
are produced as a result of burning. A slightly
radio-active element notices this specific air
pollution and this will be reported as a smoke
detection.
- Thermal fire detector: Reacts only on a relatively
fast temperature change and an absolute
maximum temperature at the ceiling. Doesn’t
react on fog expulsion.
Reacts on fog expulsion and causes
false smoke alarms
F
See also next page: fire alarm off input
BANDIT
240
PB
v.
408
p. 16 - Inputs - Functions
