Technical / Programming Manual
FT128 Rev 2.2
106
The alternative alarm algorithm can be used to reduce nuisance alarms during working
hours. The actual algorithm is shown in menu H4/U3 or EBLWin.
When FT128 has picked up a sensor value above the fire alarm level (xx° C) for a detector,
the next two values from the same detector also have to be above the fire alarm level to
activate fire alarm in FT128. (This results in approx. 14 seconds alarm delay).
The same is valid for pre-warning, except it is a lower level (xx° C) value compared to fire
alarm. The Pre-warning option under EBLWin –System Properties can be either be enabled
or disabled.
The same is valid for heavy heat alarm except it is a higher level than for fire alarm.
The fire alarm, pre-warning and heavy heat alarm levels can be set in EBLWin for the whole
system, see Section Alarm Algorithms, page 148.
The fire alarm, pre-warning and heavy heat alarm levels can be set in EBLWin collectively
for all detectors, see chapter “Alarm Algorithms” page 148. See also the FT128 Operation
Manual for more information.
14.5.1 Class A1 Algorithm
Conforms to Class A1.
Typical / maximum application temperature 25 / 50° C.
Max. / min. static response temperature 54 / 65° C.
The algorithm is as follows:
For a rate-of-rise ≤ 4° C per minute:
Fire alarm level is 56° C.
Pre-warning level is 46° C.
Heavy heat alarm level is 90° C.
For a rate-of-rise > 4° C per minute:
Fire alarm level is 46° C.
Pre-warning level is 36° C.
Heavy heat alarm level is 90° C.
The "Class A1 algorithm" will detect a fast temperature rise (rate-of- rise > 4° C per minute)
some minutes earlier than the "Class A2 algorithm".
14.5.2 Class A2 S Algorithm
Conforms to Class A2 S.
Typical / maximum application temperature 25 / 50° C.
Max. / min. static response temperature 54 / 70° C.
The algorithm is as follows:
Fire alarm level is 60° C.
Pre-warning level is 50° C.
Heavy heat alarm level is 90° C.
14.5.3 Class B S Algorithm
Conforms to Class B S.
Typical / maximum application temperature 40 / 50° C.
Max. / min. static response temperature 69 / 85° C.