4
Planning
Determining the batteries
42
Building Technologies
A6V10334410_h_en_--
Fire Safety
2015-09-29
4.4
Determining the batteries
If the aspirating smoke detector's power supply via the external power unit fails,
power is supplied via batteries.
Determining the required battery type
The battery capacity depends on the following conditions:
Buffer time required
Battery age
Country-specific specifications, as regulated in local regulations or European
provisions
The required battery capacity can be identified using the following calculations:
C
Battery
= Battery capacity
f
= Factor for the battery age
t
Standby
= Buffer time
I
PSU
= Internal current of the power supply unit
t
Alarm
= Alarm time
To achieve the system voltage of DC 24 V, two batteries must be connected in
series.
The buffer times specified in the table apply in the case of an operating
temperature within the range -5…45 °C.
The batteries are charged using the external power unit. The charging current
for the batteries depends on the battery capacity. You should therefore select
your external power unit to match the batteries' capacity.
WARNING
Switching batteries in parallel
Risk of explosion and fire
●
Never connect batteries in parallel!
●
If you need more power, you must use batteries with a higher capacity.
See also
Battery FA2003-A1 (12 V, 7 Ah,
Battery FA2004-A1 (12 V, 12 Ah,
