Decision Value; Alarm Algorithms For Smoke Detectors / Detection Levels / Offsets - Panasonic EBL128 Planning Instructions

Panasonic Eco Solutions Nordic AB
MEW01622 Rev: -
Sensor value
Obsc. in % / m
3.1
Fire alarm
offset 3.0 %
1.8
0.1
0
1 2
Smoke puff
or disturbance
13.3
13.4
detector is "dirty" and has to be replaced. See "
Figure 17. The week average sensor value will now stay on 1.8 %/m,
i.e. the detector will be more sensitive until it is replaced with a new
one.
Constant
Service signal
sensitivity
given
4 6
Figure 17. The basic working principle for an analog smoke
detector ("sensor"). Sensor value (A), Week average sensor
value (B), Fire alarm offset (3 %/m), Fire alarm level (C) and
Service level (D).
"Sensor Information" is available via menu H4/U4. Via EBLWin and
a PC connected to EBL128 you can also get continuous "Sensor
Information" for one or several detectors.
Also via the Web-server II 1598 you can get "Sensor Information" for
one or several analog detectors on a COM loop.
The smoke detector sensor values are presented as obscuration in %
per meter (%/m). (Heat detector values as °C.)

Decision value

In order to secure real fire alarms and reduce the nuisance alarms, a
decision value is calculated. The decision value is used to decide if it
is normal state, pre-warning, fire alarm or heavy smoke alarm and also
in the smouldering smoke algorithm (see page 98). The decision
value is calculated, see chapter "Filtering algorithm, page 96.
Alarm algorithms for smoke detectors /
Detection levels / Offsets
Each alarm algorithm has three detection levels:
1. fire alarm (fire alarm level = the week average sensor value + the
fire alarm offset)
2. pre-warning will be activated (if selected in EBLWin – Control
unit Properties) at a lower level (smaller offset) than for fire
alarm, i.e. pre-warning will be activated before the fire alarm from
the same alarm point.
EBL128 Planning Instructions V2.0.x
8
Smoke puff
or disturbance
92
" (D) in
Service level
Fire alarm level (C)
Sensor value (A)
Week average
sensor value (B)
Service level (D)
Time
10 12