GST200 Intelligent Fire Alarm Control Panel
Installation and Operation Manual
The Intelligent Solution
Page 44
Chapter 7 Standby Battery Calculations
Equation for calculating the battery capacity:
Battery capacity(Ah)=I
Qmax
×T
1
+(I
Qmin
+I
Lmax
+I
Fout
) ×T
2
In which:
I
Qmax
=0.6A, which is the quiescent current when the FACP is full-loaded;
I
Qmin
=0.42A, is the quiescent current when the FACP is with no load;
I
Lmax
=0.3A, is the maximum loop current;
I
Fout
=0.5A×3=1.5A, which is the alarm output current (The FACP provides 3
fire alarm outputs, output current of each is 0.5A).
T
1
is the monitoring time when the FACP is full-loaded, which shall be at least
24 hours according to EN 54-4.
T
2
is the alarm time which shall be at least 30 minutes according to EN 54-4.
From the above equation, we can get the battery capacity is 15.51Ah, so that a 17Ah
battery is recommended.