Technical / Programming Manual
FT128 Rev 2.2
131
16.5 Learning function / Learning period
Detectors 4400 and 4401 can use a Learning function, i.e. Depending on the local
temperature changes and the local occurrence of smoke where the detector is situated,
each detector can after a learning period adapt a more appropriate alarm algorithm than
the default (Normal) one, an Area Alarm algorithm
.
16.5.1 Area Alarm algorithms
Normal area is the default Area alarm algorithm for each detector. There are four other
Area alarm algorithms that can be adapted after the learning period:
Smoke – Steam area, is dependent on occurrence of smoke, i.e. level 1 = S [%/m]
≥ half the fire alarm threshold level (S).
Heater area, is dependent on rise of temperature, i.e. level 2 = deltaT [°C/168
sec.] ≥ 12 (approx. 4.3°C/min.).
Cooking – Welding area, is depending on occurrence of smoke together with rise
of temperature, i.e. level 3 = 2S+deltaT ≥ 10.
Note: S has to be ≥ 2.5 and deltaT has to be ≥ 3.
Clean area, is the most sensitive condition, requiring a very clean and stable
environment, i.e. the values for all the other types of areas (level 1, 2 and 3) must
not be exceeded.
16.5.1.1 Smoke Steam, Level 1
In a learning period there are twenty 36h-periods (i.e. 20 x 36h = 720h = 30 days = one
month).
During each 36h-period it is recorded if level 1 is exceeded at least once. If so, the 36h-
period will get a check-mark (see example).
If three or more of the 36h-periods during the learning period have a check-mark, the
smoke - Steam area alarm algorithm will be adapted. In the example this happens in the
36h-period no. 10 (i.e. after 10 x 36h = 360h = 15 days).
After the 36h period no. 20, the next learning period starts again in the 36h period no. 1.
The check-marks are inherited from the previous learning period. Depending on whether
level 1 was exceeded or not during the 36h period, a check-mark or no check-mark will
be recorded if it has exceeded and no check mark if it did not exceed.
In the example, the Smoke - Steam area algorithm condition will be changed back to the
Normal area alarm algorithm after the 36h period no. 3, since at that time only two 36h
periods are left with check-marks in the learning period now. (should one or more 36h
periods get a check-mark, the Smoke - Steam area Alarm algorithm will be adapted again
as long as three or more of the 36h-periods during the learning period have a check-mark.)
The Area Alarm algorithm can be set via EBLWin to be either automatically adapted via the Learning function or manually set
via EBLWin. If manually set, also an alternative Area Alarm algorithm can be set that can be controlled via a time channel.
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